3.2.3: Researching Potential Business Opportunities
Learning Objectives
By the end of this section, you will be able to:
- Describe opportunity screening
- Identify common sources of research data
- Explain how to research and verify business opportunities
- Identify industry and consumer sources of opportunities
In order to discover how reasonable your business idea is, you need to research many aspects of the concept. Opportunity screening is the process by which entrepreneurs evaluate innovative product ideas, strategies, and marketing trends. Focusing on the viability of financial resources, the skills of the entrepreneurial team, and the competition, this screening helps determine the potential for success in pursuing the idea and can help refine planning.
Common Sources of Research Data
As you embark on researching whether your idea is viable, a good place to start is with the sources recommended by the US Small Business Administration. These include US Census data (www.census.gov/academy), which provides insight into the population in your market area, such as the metropolitan statistical area data, as well as statistics on the economy and trade. For most entrepreneurs, research will also include asking potential customers, specifically your target customers, questions about products they like and don’t like, how a product or service could be improved, how the customer buying experience could be improved, and even where customers might go to purchase products and services instead of your business.
Small business marketers can use several no-cost or low-cost methods, including surveys, questionnaires, focus groups, and in-depth interviews. Of course, you do not need to be an expert in these areas. Business assistance is available to you from the Small Business Administration, the Service Corps of Retired Executives (SCORE), and your local Small Business Development Center. You may also have a local college or university business department that provides assistance to local area businesses.
LINK TO LEARNING
The Small Business Administration website and SCORE website are rich resources of information for entrepreneurs.
You will likely begin with secondary research —that is, data that are already available through some published source. There may be articles, research reports, or reliable Internet sources where you can research information about your industry, products, and customers. If you have the funds, you can also purchase research reports from firms that specialize in gathering research on certain topics or products. Secondary research has the advantage of being quickly available. However, secondary research often is not specific enough to provide all the details you need to know about your idea. For example, secondary research (this is research that has been developed from primary sources that is almost as useful as primary, direct research) might report how often consumers purchase shampoo, where they purchase shampoo, and what brands of shampoo they purchase. But if you want to understand the details of how people shampoo—for example, whether they shampoo then repeat, use a separate conditioner, or use a combination shampoo/conditioner product—then you would want to conduct primary research. Primary research is needed when secondary research does not address the questions you want to explore while investigating your business idea.
Primary research gathers data that do not yet exist. The information is specific to the business, product, or consumer. It takes time and money to obtain primary data. Some of the methods used to gather primary research data include developing a survey questionnaire, using secret shoppers, or using focus groups. Survey questionnaires can be simple, such as a customer comment card included on a receipt, or extensive, including dozens of detailed questions. Secret shoppers can be used by hiring a shopping service or using friends, family members, and even your customers. One local small business owner gave a friend gift certificates that could be used at his ice cream business in exchange for the friend reporting back on product quality, service, and other key issues.
Researching and Verifying the Entrepreneurial Opportunity
Whether you start your own business, buy an existing business, or purchase a franchise, researching the industry, your target market, and examining the economic and funding options are all part of performing due diligence. Due diligence is the process of taking reasonable steps to verify that your decisions are based on well-researched and accurate information. It means thoroughly researching potential pursuits, asking detailed questions, and verifying information.
Different industries have different meanings for due diligence. For example, in the legal industry, due diligence involves understanding the terms of a transaction and contract. In business finance, due diligence refers to raising capital or the work involved in merger and acquisition transactions. In the entrepreneurship field, research is necessary to verify whether the idea is really an opportunity, considering the entire process of starting the venture and funding the venture.
One of the more common questions entrepreneurs must ask is whether now is a good time to start a business. This question of timing is addressed in the investigation to determine whether the idea is merely interesting or fits the criteria of being an entrepreneurial opportunity.
An idea can move to a recognized opportunity when the following criteria are met. Figure <IP_ADDRESS> shows these three factors:
- Significant market demand
- Significant market structure and size
- Significant margins and resources to support the venture’s success
Significant market demand means that the idea has value by providing a solution to a problem that the target market is willing to purchase. This value can result from a new product or service that fills an unmet need, a lower price, improved benefits, or greater financial or emotional value. This value can also result from capitalizing on “nonconsumption.” For example, in the 1980s, the Disney Corporation realized that it was losing an opportunity to entice visitors to come to their theme parks from 9 p.m. to 9 a.m. when they were closed. So the company started having “school nights” when schools and students could use the parks at a discount.
Significant market structure and size involve growth potential and drivers of demand for the product or service. Barriers to entry are manageable, meaning that entering the industry or creating a new industry is not exceptionally difficult. If the industry already exists, there must be room within the industry for your venture to gain market share by providing a value that creates a competitive advantage.
Significant margins and resources involve the potential for achieving profit margins at a high-enough level that the work of starting the venture (including the entrepreneur’s time and energy) is worth the risks involved. If the operating costs are too high and the profit margin is too low, it is important to analyze whether the idea is truly feasible. Significant margins also include the capital requirements—how much money is needed to start the venture—as well as the technical requirements, the complexity of the distribution system, and similar resources.
Determining whether an idea has significant market demand, significant market structure and size, and significant margins and resources to support the venture’s success represents the most basic concerns when screening a business idea as an entrepreneurial opportunity.
Keep in mind that these three criteria are based partially on creating a for-profit venture. If your entrepreneurial venture is focused on solving a societal problem, you want to know that the identified problem is realistic and that there is a need for solving it. In a for-profit venture, significant market structure and margins relate to the expectation that the venture will have significant sales with significant profit margins to sustain and grow. There are also examples of profitable entrepreneurial ventures, like YouTube, that did not have any sales, but there was still an expectation that harvesting or selling YouTube would result in a significant profit for the entrepreneurial team. You can read more about Google’s purchase of YouTube .
After confirming that a business idea is an entrepreneurial opportunity, the entrepreneur should ask more detailed questions in the next phase of screening the business. Here are some examples:
- Would other people value your product or service?
- Does your product or service solve a significant problem?
- Is the market for the product definable/specific?
- Does the market have unique needs or expectations that align with your entrepreneurial opportunity?
- Is the timing right to start the venture?
- Are there infrastructure or supporting resources that need to be commercialized or created prior to your launch of the venture?
- What resources are needed to start the venture?
- What is the competitive advantage your venture offers within the industry and is this competitive advantage sustainable?
- What is the timeline between starting the venture and the first sale?
- How long before the venture becomes profitable and do you have the resources to support this timeline?
A good starting point in your opportunity screening research is to begin learning about the demographics of the market you are targeting (your target market). Demographics are statistical factors of a population, such as race, age, and gender.
The government collects census data demographics, which can provide a snapshot of the population in your city or town. Census data include the total population, a breakdown of the population by age, gender, race, and income, and some other useful data.
LINK TO LEARNING
The US Census website and your local chamber of commerce can help you learn more about the demographics of your target market or region.
For example, if you were considering opening a new ice cream store with unique flavors preferred by children, census data could tell you the number of children living in the area, the ratio of boys to girls, their ages, and the general income levels of the families in town. The census data would help you determine the size of the market and potential target market, local market growth, income levels, and key demographics that might fit the potential customer profile. Of course, there is other information you might want to collect, such as the percentage of the population that had lactose intolerance. If you found that a significant portion of your market was lactose intolerant, this could be your identified opportunity: You could create a lactose-free ice cream store or expand with a variety of lactose-free flavors. The census data also help identify where to locate your entrepreneurial venture. For example, if your lactose-free ice cream was expensive because of the necessary ingredients, you would not want to open your store in a low-income area.
There is a vast amount of data and information available through the Internet that can support your success in making informed decisions as you explore the feasibility of opening a successful venture. Or you can purchase more detailed consumer data through providers such as Claritas Research, which gathers information on demographics, consumer lifestyles, attitudes, and behaviors ( https://claritas360.claritas.com/myb...egments/?ID=70 ). For many small business startups that cannot afford sophisticated research data, the entrepreneur will probably have to rely on census data along with information that the local economic development council is able to provide.
WORK IT OUT
T-Shirt Startup
Create your own t-shirt line to target your classmates.
- What would be the theme?
- How much would you charge?
- Where would you sell the shirts?
- What are the expected sales of the business?
- What are the resources needed to get started?
After analyzing demographic data, the entrepreneur can then develop and conduct some basic research, which could range from observing customers to shopping at potential competitors. Entrepreneurs can also uncover business opportunities by asking questions of, and listening to, their customers, if they are working within the industry or looking for new entrepreneurial opportunities with a similar target market. Sometimes an easy and inexpensive customer survey can uncover problems and opportunities. Entrepreneurs can also gather information using their social media accounts and customer sales records.
For example, imagine a men’s clothing store in Denver that maintained a detailed customer database that they used primarily to order the colors and sizes their customers were most likely to purchase. A marketing consultant begins researching customer data and finds a number of former customers who had not shopped at the store for a year or more. The consultant uncovers some lapses in service that had cost the store thousands of dollars in sales. Store management, working with the information from the consultant, develops a direct marketing campaign that helps bring back former customers and adds new customers, resulting in a substantial sales increase.
The lesson here is that research is important at all stages of the business—before you start your business and consistently thereafter. Markets change as new people move in or out of an area, styles and preferences change over time, and new technology can radically impact what customers want to buy. We all know of businesses like Blockbuster or Xerox that ignored evolving technology, to the detriment of their success. Constantly tracking changes in the external environment and competitive arena is an ongoing activity that supports the continued success of the venture.
A popular tool for market analysis is a product from Claritas Research called Potential Rating Index for Zip Markets (PRIZM), which characterizes census data according to certain lifestyle traits, even down to the neighborhood level. As an example, let’s see how PRIZM can help us better understand the consumer market of a small town in Massachusetts. Oxford, Massachusetts (zip code 01540), has a population of 11,653, with slightly more half being female; a median income of $70,444; and a median age of 42.3 years. PRIZM data give us a better understanding of consumers than census data do in Oxford by examining the five dominant lifestyle segments from within PRIZM’s sixty-six segments. The PRIZM segments are based on socioeconomic rank determined by characteristics such as income, education, occupation, and home value. A thorough analysis of available data could suggest the most likely products and sources consumers in this zip code market would likely purchase.
Entrepreneurs might also obtain data from economic development agencies, the local chamber of commerce, the state small business development center, or industry associations. Of course, lots of data can be found with a good search on your computer. Your university reference librarian can tell you what resources they have available and which resources would best fit your research question(s) and area of focus for your idea.
ENTREPRENEUR IN ACTION
Elon Musk’s SpaceX
There have been many instances in which products have been promised but fail in their implementation. Space travel—think Elon Musk’s venture SpaceX (Figure <IP_ADDRESS>)—is an example of a bold concept that is still in the feasibility phase. Is it even possible to send humans to Mars? This is an extreme but interesting example for considering product feasibility.
Another application of the SpaceX technology is to develop satellite-based Internet access that can provide service to billions of people who do not already have Internet service. However, the project will require new satellite networks, and it may take twenty years to fully develop.
- What short-term and long-term considerations are necessary in the project?
- As the concept will take twenty years of satellite development, how can technological changes be incorporated into the development of the idea?
- Given the description of an entrepreneurial opportunity, does this idea fit that definition?
What should you do if your idea does not fit these criteria—significant market demand, market structure and size, and margins and resources—and your passion to develop the idea into an opportunity and new venture is still strong? This is also part of the entrepreneurial process. You, as the lead entrepreneur, are charged with the task of identifying the obstacles to turning your idea into an opportunity and what actions are necessary to overcome these. This could mean adjusting the idea, adding new features, or even removing some features. Adding new features should focus on increasing the value or benefit offered by the product or service, or creating a tighter alignment with the needs of the target market. Removing features could decrease the production costs or even the complexity in using the product.
As part of your research to verify whether your idea is truly an entrepreneurial opportunity, researching your state’s laws and regulations is essential. Conduct an Internet search for your state’s business regulations applicable to your business. You will need to comply with these laws, as well as purchase any licenses and permits necessary for your business. You should also check with your local or county government for additional local regulations, including zoning and signage laws. Remember that laws vary by state, so what is legal in one state may not be legal in another, or there might be stricter regulations. For emerging industries, the regulations and laws can fluctuate as industries evolve. This is especially true for emerging industries such as the sale and distribution of medical marijuana.

Getting a License or Permit to Start a Business
When starting a business, be sure that you have all the required licenses and permits, keeping in mind that you may need licenses from federal, state, county, and local government agencies. You can start with the SBA website . Another helpful resource is Fundera , an online financial resource that provides information about obtaining business licenses in all fifty states and links to essential government organizations for each state. And try nav.com as well.
States regulate a larger number of business activities than the federal government. Business activities that are regulated locally include auctions, construction, dry cleaning, farming, plumbing, restaurants, retail, and vending.
- Select a business in a regulated industry and research what would be needed to start the venture in a specific locale.
Many estimates indicate that half of all new businesses will no longer exist within the first five years, but good research can help you avoid your business becoming a statistic. 16 On the surface, this fact can be daunting. However, there are many reasons why a business no longer exists that can reflect a positive outcome, such as the sale of a business or a merger with another business. Another example is when an entrepreneur intentionally starts a venture knowing that there is a short-term timeline for success, with the expectation that new technology will replace the gap that the venture originally filled. Most entrepreneurs are not big risk-takers but understand that there are no guarantees in starting a new business venture. Instead, entrepreneurs tend to take calculated business risks based on the best research they can gather. At some point, however, the entrepreneur recognizes that despite all the good research they have gathered, they still need to take a leap of faith when starting their new venture.

Why Small Businesses Fail
Why do half or more of new small businesses no longer exist after the first five years? In many cases, it is failure of the business. The Small Business Institute at Thomas College in Maine has cited factors in Table <IP_ADDRESS> as the most common reasons for small business failures. Many business development agencies have compiled similar lists.
| Reason | Description |
|---|---|
| Low sales | Entrepreneurs may have overestimated sales, assuming they could take sales away from established competitors. |
| Lack of experience | Running a business is hard, and a new business can be especially challenging, as it is difficult to prepare adequately for the unexpected. |
| Insufficient capital | When calculating how much money you will need to start your new business venture, be sure to account for the time it will take before your business breaks even and be sure also to allow for some contingency funds for when the unexpected happens. |
| Poor location | For some types of businesses, location is critical. Of course, location may be less important for a home-based business and not at all important for an Internet business. |
| Poor inventory management | Too much inventory results in the business becoming cash-strapped and unable to buy advertising or other important goods and services. |
| Overinvestment in fixed assets | Especially when starting a business, it is usually less expensive to lease or purchase used equipment, thereby saving cash for meeting operational expenses. |
| Poor credit arrangement management | Start your venture small and limit the amount of money you need to borrow. Work with your banker from the beginning by sharing your business plan and vision for the business with the banker and, most important, show that you are proactive in planning for when you will need to borrow money. |
| Personal use of business funds | The owner should pay him/herself a minimal salary and not dip into business funds. If the business has done well, the owner will earn additional funds at the end of the year. |
| Unexpected growth | Surprisingly, some businesses fail because the business owner cannot manage growth. Growing a new venture, especially if the growth is at a higher rate than expected, can create surprising challenges. For example, if creating a product, you need to consider the capacity of the factory where you are producing the product. If you are at 100 percent capacity and your orders increase, you will need to think about what actions can support this increase in demand. If you cannot meet the demand, you will have unhappy customers and negative publicity that will reflect negatively on your leadership and managerial skills. Your lack of planning for this surge in sales may open opportunities for someone else to start a competing business. |
| Competition | Many small business owners underestimate their competition. Remember, if there is money to be made, there will be competition! Larger competitors can beat you every day of the week on price, so find another way to challenge competitors. |
- Given the preceding reasons for small business failure, what can be done to head off such failure?
- Why is it necessary to assemble a team of professional advisors to address financial, personnel, legal, accounting, and other business issues?
- Why is it vital to identify suppliers and personnel to be able to provide a product or service?
- What factors are important when considering whether a product should be manufactured internally or outsourced to a third party?
Let us analyze, as an example, opportunity recognition displayed by a company called Sweet Beginnings. Eddie Griffin, Kevin Greenwood, and Tiffany Chen were all residents of Chicago who were seeking jobs and a fresh start on life after serving time in prison. They wanted a chance to rebuild their lives and the ability to support themselves financially. Unfortunately, the odds were against them in their North Lawndale community: There was a 40 percent unemployment rate, 57 percent of residents had criminal histories, the average annual income was only $25,000, and the area was known for drugs, sex workers, and gangs. Statistically, they were destined to return to the criminal justice system.
But fate intervened in the form of Brenda Palms Barber, who knew all of these statistics. Palms Barber was the Executive Director of the North Lawndale Employment Network (LEN). When employers refused to hire Griffin, Greenwood, and Chen, whom she had coached, she researched what it would take to open various businesses, including a temp agency, a landscaping company, and a delivery service, with the intent to offer employment to LEN clients. A recommendation from a board member’s connection led her to consider, of all things, raising bees. It was not until she learned that the ins and outs of the apiary profession are passed on by word of mouth that she felt it was ideal for her clients who often faced learning challenges due to limited academic experience.
In 2005, Palms Barber founded Sweet Beginnings, a social enterprise that employs former inmates and teaches them job skills by running an apiary business directly in the heart of North Lawndale. The Sweet Beginnings brand, Bee Love (shown in Figure <IP_ADDRESS>), sells honey and honey-infused skincare products in airports, hotels, and supermarkets, including Whole Foods. Palms Barber recognized that the skills her potential employees learned in the streets were transferrable to running and managing the business.
Palms Barber also realized that a product gap existed between customer needs and products offered. She identified the niche market of customers who wanted all-natural skincare products and liked the idea of purchasing them from a social enterprise. Bee Love positioned itself for success as an appealing, high-end natural product to environmentally conscious consumers willing to pay a premium for it.
Palms Barber recognized an opportunity when she identified the societal problem of employment for people who had experienced incarceration. In seeking solutions to this problem, she encountered roadblocks from employers’ resistance to hiring ex-prison inmates. She then researched other possible solutions including business startups. The idea of raising bees at first seemed an unusual solution to the problem of employment for her unique clients. In her due diligence, she identified a gap between customer preferences for all-natural skincare products and currently available offerings. Combining these ideas resulted in the opening of Bee Love. The fits between the clientele of ex-inmates, apiary, and skincare products supported the opening of this unique venture. Exploring the gaps was part of the process of finding the right solution and realizing that the idea of starting a business to support ex-inmates was an actual opportunity worth developing into a new venture.
Industry Sources of Opportunity
Your research process should include learning everything you can about the industry you plan to enter. This will help you to identify opportunities. An excellent source for industry information is the business reference section of your college library. Industry averages are available in reference books and can also be found at Dun & Bradstreet/Hoovers (www.hoovers.com/industry-analysis.html). The industry analysis contains important information including a brief description of the industry and its characteristics, the competitive landscape, along with products, operations, and technology.
Industry sources reveal knowledge about a specific industry from the perspective of identifying unmet needs or areas for improvement within that industry. For example, Airbnb reshaped the hotel industry by connecting travelers with property owners, so that the travelers could rent the property when the owner was not using it. As Airbnb has grown, the company has made improvements to their offerings in meeting the needs of the traveler’s demand based on property location and in categorizing the supply (the homeowner’s property) for increased efficiency, meeting the needs of both the property owner and the traveler. Researching specific industries from supply and demand perspectives, and noticing unused supplies, as we saw in the Airbnb example, also applies to other industries, such as a sandwich shop. What happens to the unsold bread at the end of the day when there is an excess supply? For Stacy Madison and her pita sandwich food cart, unsold bread presented an opportunity to create pita chips by turning an oversupply into sliced and seasoned pita chips.
Almost every industry is worth investigating from the perspective of identifying unused resources or extra resources that could be restructured for what are known as a shared economy or a gig economy . A shared economy considers that there are times when an asset in not in use. This downtime when the asset is not in use provides an opening for someone else to use that asset, like Airbnb. Other companies, like Uber, Lyft, DoorDash, and Postmates, support the gig economy in aligning a person’s choices for when they want to work with the flow of the work demand. A gig economy is an open or fluid market system with temporary positions made up of independent short-term workers. In these examples, we can see the alignment of supply and demand. The entrepreneurial opportunity happens in providing a platform to assist in connecting the supply and demand.
The tech sector, for example, is continually adapting to change. Items such as 3D printers and mobile devices are making the technology landscape expand. As new products come to market, the need for applications and increased efficiency abound. Several other industries are experiencing growth, including health care and nutrition. According to Global Market Insights (2019), the clinical nutrition market will exceed $87,530.7 million dollars by 2025. This same source reported that this industry was valued at over $10,562.7 million in 2018, a significant increase over the previous seven years. Drivers in this industry include sedentary lifestyles and related health issues, such as obesity. The result of these societal changes is an increase in clinical nutrition products and home healthcare services. According to business management author, professor, and corporate consultant, Peter Drucker, entrepreneurs excel at finding and developing potential business opportunities created by social, technological, and cultural changes.
Consumer Sources of Opportunity
Consumer sources of opportunities relate to changes in our society, such as new habits or behaviors brought about by exposure to new information. For example, most people feel the pressure related to having less free or unrestricted time. Figure <IP_ADDRESS> tracks the average number of hours worked by country per worker per year.
The International Labour Organization and Bureau of Labor Statistics report that most people in the United States work more than forty hours per week, work significantly more hours per year than workers in many other countries, and are vastly more productive than they were half a century ago.
Another consideration is tracking where our time is spent during commuting. The average commute time in major cities in the United States is twenty-six minutes, ranging from thirty-eight minutes in New York City to the shortest commute time of twenty minutes in Buffalo, New York. When we add in commute times, work hours, and other required activities like sleeping and eating, we find that people struggle to find time for relaxation and personal activities. This large trend leads to recognizing that our working population in the United States and other countries would value novel approaches to completing tasks and making life simpler. For instance, several businesses have looked at making life easier and saving the consumer time, such as Amazon’s One-Click-Checkout, grocery delivery, and product recommendations. Other examples include mobile businesses like pet grooming that come to your home, or diaper delivery services that pick up used diapers, wash and dry them, and return clean diapers to your home. Understanding consumer needs and problems opens the possibility of creating a business that addresses those needs or problems.
Another consumer trend is the demand for affordable housing. One solution involves offering more affordable “tiny homes” that make homeownership more accessible (Figure <IP_ADDRESS>). As one entrepreneurial opportunity materializes into a new product, spin-off ideas may also arise. The tiny home concept attracted the attention of groups that assist homeless veterans. The Veterans Community Project in Kansas City, has developed a community of forty-nine tiny homes for homeless veterans and the project is so successful that more than 500 cities around the country are building tiny home housing projects for veterans there.
ENTREPRENEUR IN ACTION
Vestergaard
Vestergaard has a mission to prevent diseases, especially for vulnerable populations around the world, and to contribute to a healthier and more sustainable planet through good actions.
LifeStraw is a product that Vestergaard launched in 2005, making water safe to drink in areas where clean water is not readily available and redefining beliefs around safe drinking water. LifeStraw uses a combination of a hollow fiber membrane, a filtration process, and in some products, a second filtration process to remove chemicals like chlorine, lead, and pesticides.
- Apply the concepts of supply and demand in describing LifeStraw from the perspective of an entrepreneurial opportunity.
- What are three drivers that support the creation of LifeStraw?


10.4: Preparing Alkyl Halides from Alkenes - Allylic Bromination
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- Steven Farmer, Dietmar Kennepohl, & William Reusch
- Cañada College
Objectives
After completing this section, you should be able to
- write the equation for the bromination of a symmetrical alkene using N-bromosuccinimide.
- predict the product formed when a given symmetrical alkene is treated with N-bromosuccinimide.
- identify the reagent, the symmetrical alkene, or both, needed to produce a given allyl halide by allylic bromination.
- list the following radicals in order of increasing or decreasing stability: allyl, vinyl, primary alkyl, secondary alkyl, tertiary alkyl, methyl.
- explain the ease of forming an allyl radical, and the difficulty of forming a vinyl radical, in terms of relative $\ce{\sf{C–H}}$ bond dissociation energies.
Study Notes
We have discussed the electrophilic addition of X 2 and HX to alkenes as a route to forming alkyl halides (Sections 7.8 and 8.2 ). In this section we introduce bromination at the allyic position with N-bromosuccinimide (NBS). Notice that at the moment we are restricting our studies to the allylic bromination of symmetrical alkenes, such as cyclohexene. When we introduce an element of asymmetry, we find that more than one allyl radical can be formed; therefore, we must assess the relative stability of each radical when trying to predict which product will predominate. The method of doing this assessment is described in the next section.
Allylic Bromination
Previously, alkyl halides have been produced though reactions with alkenes. Hydrogen halides (HCl, HBr, and HI) react with alkenes in an electrophilic addition reaction discussed in Section 7-8 to yield alkyl halides as products. Also, Bromine (Br 2 ) and chlorine (Cl 2 ) can react with alkenes to provide dihalogenated products as discussed in Section 8-2 .
Another method for preparing alkyl halides from alkenes is with N-bromosuccinimide (NBS) in carbon tetrachloride (CCl 4 ) solution with the presence of light. The reaction specifically causes the substitution of bromine with a hydrogen attached to a carbon adjacent to the double bond - the allylic position.
General Reaction
Mechanism
The allylic bromination with NBS is analagous to the alkane halogenation reaction ( Section 10. 2) since it also occurs as a radical chain reaction. NBS is the most commonly used reagent to produce low concentrations of bromine. When suspended in tetrachloride (CCl 4 ), NBS reacts very rapidly with the HBr formed during the reaction mechanism to provide bromine (Br 2 ) which is required for the reaction to continue. Under the correct conditions, NBS provides a constant but very low concentration of Br 2 in the reaction mixture. The low concentration of Br 2 helps to prevent the formation of unwanted side-products.
The mechanism starts with the formation of a small amount of bromine radical which then abstracts an allylic hydrogen to form an allylic radical and HBr. The HBr can then react with NBS to form the Br 2 required for the reaction. The allylic radical then abstracts a bromine atom from Br 2 to form the allyl halide product and a bromine radical. The bromine radical produced allows the reaction to continue.
The predominance of allylic substitution over other positions is based on bond dissociation energies. An allylic C-H bond has a strength of about 88 kcal/mol which is much weaker than a typical alkyl C-H bond (98 kcal/mol) or vinylic C-H bond (111 kcal/mol). Therefore, an allylic C-H bond is most likely to form a free radical and react.
Because a allylic C-H bond requires less energy to undergo homolytic cleavage than even a tertiary C-H bond, it can be inferred that a allylic radical is more stable than a tertiary radical. The ordering of stability in radicals can be expanded to include vinylic and allylic radicals. The enhanced stability of allyl radicals can be attributed to resonance stabilization which will be discussed in the next section.


15.11: Steps of Capital Budgeting
Learning Outcomes
- Discuss the steps in the capital budgeting process
So let’s say our supervisor comes to us with the following situation: We need to add a product line, and we have three options. Each option requires capital outlay including new equipment and manufacturing space. They all require a quite substantial initial investment. Where do we start?
Watch It
The first step will be a screening decision. In this step we will look at all of the projects, and determine whether they meet the company’s basic guidelines for consideration. Our company, may for example, require a 20% rate of return on a new investment before it will even be considered as an option. Once we screen all of the potential options, if any meet this guideline, we can move on the the preference decision.
The preference decision takes all of the projects that meet the screening process and then decide which to choose. Perhaps, we have three machines available that would all provide us with a 20% rate of return on the investment each year. Now, we need to decide between the three machines, which one to pick!
We can use a variety of methods once we get to this point to make our choice!
Practice Questions


9: Thermochemistry
Useful forms of energy are also available from a variety of chemical reactions other than combustion. For example, the energy produced by the batteries in a cell phone, car, or flashlight results from chemical reactions. This chapter introduces many of the basic ideas necessary to explore the relationships between chemical changes and energy, with a focus on thermal energy.
Contributors
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Paul Flowers (University of North Carolina - Pembroke), Klaus Theopold (University of Delaware) and Richard Langley (Stephen F. Austin State University) with contributing authors. Textbook content produced by OpenStax College is licensed under a Creative Commons Attribution License 4.0 license. Download for free at<EMAIL_ADDRESS>).


11.11: Timur
It was under Timur (1370 – 1405) that Central Asia moved to the fore of world events. He attempted to soothe the persistent differences that existed between the steppe and sedentary societies and actually developed a political arrangement that could harness the best attributes of each society, without the dangerous side effect of communal violence associated with combining the two civilizations. He also constructed a new political and military machine that was deeply ingrained in the political background of the Chagatai Khanate, even while he acknowledged that Inju satisfied neither the nomad nor the settled society and eliminated the practice. Astutely recognizing that serious conflict existed between these two incongruent cultures under his control, Timur provided a framework for both societies to live in harmony.
Born in 1336 near Kesh in modern day Uzbekistan, Timur came out of Central Asia and was a product of the Turko-Mongol fusion. He descended from an aristocratic Mongol clan, but he was raised as a Muslim and spoke a Turkic language. Although Timur himself was a native to Transoxiana, he could not assert Genghis-Khanid legitimacy. Unable to trace his ancestry to Genghis Khan, he could not take the title of khan in his own right. Timur understood that because he did not have the correct pedigree, he would have to earn it. His solution was to take the title of emir, meaning commander, and rule through a Chagatayid puppet khan acting as a figurehead. The emir also married into the family of Genghis Khan. While the law of descent was not intended to work this way, Timur changed it to accommodate his children, who would be able to claim Genghis-Khanid legitimacy.
To strengthen the security of his position as emir, he constructed a system of support that ordered his political connections in a series of concentric rings. In his primary circle resided his family and close allies. The second ring consisted of loyal tribes and Timur’s own Barlas Clan, from which he traced his lineage. The third circle was made up of those peoples Timur had defeated on the battlefield; the second and third rings balanced one another. The outermost bands included Timur’s hereditary professional administrators and bureaucrats, soldiers from the plains serving in his cavalry units, and finally the Persian urban and agricultural populations, from which he recruited his infantry and siege units.
Like many transitional figures in history, such as Suleiman the Magnificent, Timur bridged the medieval and modern worlds. He attempted to imitate Genghis Khan’s success in the field and designed a novel military machine that was well adapted to the environment in which he lived. His military was the product of a Turko-Mongol fusion, employing Turkic siege techniques and the Mongol cavalry. Unlike Genghis Khan, however, Timur increasingly combined his cavalry, siege, and infantry units, placing his heavy cavalry at the center of formations. His army also utilized an early form of artillery. He ventured to monopolize the market on gunpowder technology so that other powers could not benefit from it.
Timur was determined to keep his volatile army occupied, so they would not be a burden to the sedentary population in his realm. It was in this context that he developed a formula for success that promoted peace at home and war abroad, a policy that best served the interests of the merchants and townspeople. He externalized the violence of the steppe and destroyed all of the other trade routes that bypassed his territory. Timur attempted to reactivate and dominate the Silk Road and diverted trade to his lands in order to help rebuild the cities that had been damaged from years of Mongol and nomad rule. He did not aim at permanent occupation or the creation of new states; he just wanted to devastate, even going so far as to campaign against the Golden Horde, Delhi Sultanate, and the Ottoman Empire, all in an effort to redirect trade in his direction.
Timur began his military campaigns attempting to secure the back door of the steppe. During this period, which lasted from 1370 to 1385, he conquered and subdued Mogholistan to the northeast, with the aim of securing the core central land route of the Silk Road. (The Chagatai Khanate had already been divided into two parts by the 1340s, Transoxania in the west, and Mogholistan in the east.) Then he engaged the Golden Horde between 1385 and 1395. The Golden Horde had been the master of the northern trade route that bypassed Timur’s territory. In order to eliminate this option, he went to war against them in order to divert trade to toward his lands. Timur showed his strategic genius in these expeditions. He defeated a steppe power on the steppe. He put the pieces of his army together in such a way so that he could take his enemies on in their arena and on their terms. In this manner, Timur crushed Tokhtamysh , leader of the Golden Horde, in 1395. During the course of this campaign, Timur destroyed their principle trade cities of Astrakhan and Sarai. An interesting byproduct of Timur’s campaign against the Golden Horde was that it precipitated the rise of the Grand Duchy of Moscow . He had weakened the Golden Horde to such an extent that it made it possible for Moscow to throw off the Mongol yoke.
Timur raided into India from 1398 to 1399 and dealt a blow to the southern sea route that connected the Occident to the Orient. This expedition was primarily for looting, since he never intended to conquer and annex the territory of Nasir-ud-Din Mahmud Shah Tughluq , the last member of the Tughluq Dynasty of the Delhi Sultanate. During this campaign, Timur’s tactical brilliance was on full display; he had an uncanny ability to adapt to any martial environment that he confronted. For instance, when threatened with a cavalry of war elephants, Timur responded by unleashing a pack of camels laden with incendiary material to charge the enemy lines. Shrieking dromedaries with their backs ablaze incited utter pandemonium among Nasir-ud-Din’s cavalry of elephants, who rampaged through the sultan’s own lines. Timur easily routed the sultan’s forces. When faced with the townspeople of Delhi rising up against their aggressors, Timur brutally sacked the capital of the sultanate and justified the violence in religious terms. His was a Muslim victory over the Hindu unbelievers of India.
In Timur’s final period of conquest, which lasted from 1400 to 1404, he campaigned against the Islamic far west, directing his army against the Ottomans. Actually, Timur had initially attempted to avoid conflict with the Ottomans, whose forces had earned an impressive reputation on the battlefield. In fact, Timur had even tried to negotiate with Bayezid I, the Ottoman Sultan, offering him part of Golden Horde’s territory west of Dnieper River. But these two expansionist realms inevitably came into conflict in eastern Anatolia. The conflict between the two empires began as the Ottomans expanded to the east and took control of some Turkmen tribes in eastern Anatolia already under the protection of Timur. The emir responded by taking some other Turkmen tribes under Ottoman suzerainty. Offensive missives replete with insulting incriminations ensued. Timur bided his time, waiting for the perfect moment to attack the Ottomans. In 1402, he launched a devastating attack into the heart of Anatolia, as the Ottomans were preoccupied with campaigning against the Hungarians. During the Battle of Ankara in 1402, Timur managed to convince many of the Ottoman forces to defect to his side. He captured the Ottoman sultan, who died in captivity three months later. Timur had not attempted to conquer the Ottomans; he just wanted to punish them for their unwillingness to cooperate. His Levantine expedition also seems to have been designed to weaken the western terminus of the Silk Road in Aleppo, Syria.
Timur died in 1405 while on a campaign against the Ming Dynasty. He had built an empire that spanned the breadth of Central Asia. Unlike Genghis Khan, whose empire continued to expand after his death, the sons of Timur and their followers squabbled over succession, leading to a series of internecine battles. Members of the Timurid Dynasty competed among themselves, with commanders switching loyalties. The empire consequently fragmented. The successors of Timur could not manage the difficulties of governing an empire, and it withered away quickly. The political situation resembled that which Chagatayids had to contend with, the steppe military that had been redirected, but with Timur’s death, they returned. A number of Timurid rulers followed; a weak state emerged from all this strife.
Terror and Destruction
Timur certainly committed what we would describe today as war crimes; there definitely was an element of terrorism to his campaigns. In fact, as an admirer of architecture, he is known to have constructed pyramids of human skulls. Extant accounts describe him slaughtering 100,000 Indian prisoners following the Delhi uprising. But not all destruction was the same; and there was a definite difference between that of Genghis Khan and Timur. The emir’s annihilation of the region was not meant to serve a utilitarian purpose so much as to inflict suffering. Genghis Khan’s used terror as a method to protect his troops, whereas Timur engaged in terror and destruction for pleasure.
Legacy
A product of the Turko-Mongolian fusion, Timur had been the first to reunite the eastern and western parts of the Chagatai ulus. His empire represents the construction of the political boundaries passed down to posterity; the maintenance of this space would define boundaries of modern day Central Asia up to the twentieth century. Under Timur we see growing political and cultural distinctions between Iran, Central Asia proper, and India begin to cement. In this context, we see a split taking place on the steppe that will lead to a differentiation of the Uzbeks and Kazaks. By the late fourteenth century, the tribes on the steppe to the north will become known to Muslim writers as Kazaks, whereas the tribes to the south will be increasingly referred to as Uzbeks, a differentiation that has continued to persist and helped to delimit modern borders.


11.24: Reading- Demonstrating Customer Value
Introduction
Rent the Runway is a company that lets customers borrow expensive designer dresses for a short time at a low price—to wear on a special occasion, e.g.— and then send them back. A customer can rent a Theia gown that retails for $995 for four days for the price of $150. Or, she can rent a gown from Laundry by Shelli Segal that retails for $325 for the price of $100. The company offers a 20 percent discount to first-time buyers and offers a “free second size” option to ensure that customers get the right fit.
Do the customers get a bargain when they are able to wear a designer dress for a special occasion at 15 percent of the retail price? Does the retail price matter to customers in determining value, or are they only considering the style and price they will pay for the rental?
What does value really mean in the pricing equation?
The Customer’s View of Price
Whether a customer is the ultimate user of the finished product or a business that purchases components of the finished product, the customer seeks to satisfy a need through the purchase of a particular product. The customer uses several criteria to decide how much she is willing to spend in order to satisfy that need. Her preference is to pay as little as possible.
In order to increase value, the business can either increase the perceived benefits or reduce the perceived costs. Both are important aspects of price. If you buy a Louis Vuitton bag for $600, in return for this high price you perceive that you are getting a beautifully designed, well-made bag that will last for decades—in other words, the value is high enough for you that it can offset the cost. On the other hand, when you buy a parking pass to park in a campus lot, you are buying the convenience of a parking place close to your classes. Both of these purchases provide value at some cost. The perceived benefits are directly related to the price-value equation; some of the possible benefits are status, convenience, the deal, brand, quality, choice, and so forth. Some of these benefits tend to go hand in hand. For instance, a Mercedes Benz E750 is a very high-status brand name, and buyers expect superb quality to be part of the value equation (which makes it worth the $100,000 price tag). In other cases, there are tradeoffs between benefits. Someone living in an isolated mountain community might prefer to pay a lot more for groceries at a local store than drive sixty miles to the nearest Safeway. That person is willing to sacrifice the benefit of choice for the benefit of greater convenience.
When we talk about increasing perceived benefits, we refer to this as increasing the “value added.” Identifying and increasing the value-added elements of a product are an important marketing strategy. In our initial example, Rent the Runway is providing dresses for special occasions. The price for the dress is reduced because the customer must give it back, but there are many value-added elements that keep the price relatively high, such as the broad selection of current styles and the option of trying a second size at no additional cost. In a very competitive marketplace, the value-added elements become increasingly important, as marketers use them to differentiate the product from other similar offerings.
Perceived costs include the actual dollar amount printed on the product, plus a host of additional factors. If you learn that a gas station is selling gas for 25 cents less per gallon than your local station, will you automatically buy from the lower-priced gas station? That depends. You will consider a range of other issues. How far do you have to drive to get there? Is it an easy drive or a drive through traffic? Are there long lines that will increase the time it takes to fill your tank? Is the low-cost fuel the grade or brand that you prefer? Inconvenience, poor service, and limited choice are all possible perceived costs. Other common perceived costs are the risk of making a mistake, related costs, lost opportunity, and unexpected consequences, to name but a few.
Viewing price from the customer’s point of view pays off in many ways. Most notably, it helps define value–the most important basis for creating a competitive advantage.
Contributors and Attributions
- Revision and adaptation. Provided by : Lumen Learning. License : CC BY: Attribution
- Chapter 9: Pricing the Product, from Introducing Marketing. Authored by : John Burnett. Located at : http://solr.bccampus.ca:8001/bcc/file/ddbe3343-9796-4801-a0cb-7af7b02e3191/1/Core%20Concepts%20of%20Marketing.pdf . License : CC BY: Attribution
- Bibhu Mohapatra: NY Fashion Week. Authored by : j-No. Located at : https://www.flickr.com/photos/j-no/6167576401/ . License : CC BY-NC-ND: Attribution-NonCommercial-NoDerivatives


11.1: What Is Copyright?
Copyright is the law. While digital technology has made some aspects of copyright more complex, knowing the basics can help you to use material legally and protect your own creative works.
You create copyrighted works regularly. When you write an original email or paper, record a song or video, or take a photograph you have created a work that is protected by copyright. It is important to know how to manage your rights as a creator.
Every day you work with copyrighted materials created by other people. Whenever you read a book, download a song, stream a video, or play a video game, you are potentially dealing with copyrighted materials. It is important to understand what is and is not covered by copyright law and the ways you may use these works under the law.
Copyright Law
U.S. Copyright Law has its origin in the U.S. Constitution:
The Congress shall have the power … to promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries.
– U.S. Constitution Article 1, Section 8
The purpose of copyright is to encourage the creation and sharing of creative works. Copyright gives creators an incentive to produce and share new works by granting them exclusive rights to their work for a limited time. This provides an opportunity for a creator to benefit from his or her work.
In the United States, Congress determines the limits of this monopoly, including the length of time that copyright coverage lasts. These limits can (and have) changed over time. Copyright laws differ from country to country.


1.15: Management Roles
- Differentiate between leadership, informational, and decision-making roles.
We have discussed the types (levels) of managers and some of their responsibilities but not their specific activities. All managers must be comfortable with three main types of activities or roles. To do their jobs, managers assume these different roles. No manager stays in any one role all of the time, but shifts back and forth. These roles are leadership (or interpersonal), informational, and decision making. They were written about in detail in the 1970s by Henry Mintzberg, a professor at McGill University in Canada. His classifications are still one of the most studied descriptors of management roles today. [1]
Leadership and Interpersonal Roles
Which type of manager spends more time in leadership activities? The short answer is all effective managers display leadership characteristics. Leadership is the ability to communicate a vision and inspire people to embrace that vision.
Top managers are often required to fulfill what Mintzberg described as figurehead activities. They are the public face of the management team and represent the business in legal, economic, and social forums. [2] Middle managers are also leaders, although their focus may be more on interpersonal skills, such as motivating employees, negotiating salaries, and encouraging innovation and creativity. First-line managers lead both by example when they actively participate in the tasks assigned to their workers and by modeling the policies and work ethics of the organization.
Informational Roles
Informational roles involve the receiving and sending of information—whether as a spokesperson, a mentor, a trainer, or an administrator. A top manager is a voice of the organization and has to be aware that even personal opinions will reflect (for better or worse) on the business. With the free flow of information on the Internet, it is very difficult for top managers to separate their personal identities from their corporate positions. For example, there was a consumer backlash in 2017 when Uber CEO Travis Kalanick accepted a seat on President Trump’s economic advisory council. Kalanick initially said that he was “going to use [his] position on the council to stand up for what’s right.” He resigned a few days later in response to the protest. [3]
Middle managers must skillfully determine what information from top management should be shared with others, how it should be interpreted, and how it should be presented. Similarly, they must weigh the value of information they receive from first-line managers and employees in order to decide what to forward to top management. If transmitted information tends to be untrue or trivial, then the manager will be viewed as a nonreliable source and his or her opinions discounted.
The informational role for first-line managers is primarily one of disseminating what they have been given and helping the employees to see how their own contributions further organizational goals. They have a responsibility to see that the employees understand what they need to be successful in their jobs.
Decision Making Roles
All managers are required to make decisions, but managers at different levels make different kinds of decisions. According to Mintzberg, there are four primary types of management decision roles. These include the following:
- Entrepreneur. The entrepreneurs in a firm are usually top-level managers. They identify economic opportunities, lead the initiative for change, and make product decisions.
- Disturbance handler. Top and middle managers will react to disturbances (unexpected events) in the organization—whether internal or external. They will decide what corrective actions should be taken to resolve the problems.
- Resource allocator. All levels of management will make resource allocation decisions, depending upon whether the decision affects the entire organization, a single department, or a particular task or activity.
- Negotiator. Depending on the effect on the organization, most negotiation is done by top and middle-level managers. Top managers will handle negotiations that affect the entire organization, such as union contracts or trade agreements. Middle-level managers negotiate most salary and hiring decisions. [4]
To summarize, managers must play many roles. Some are better than others in particular roles and will tend to be called on for those jobs. Putting a diverse management team in place will ensure that the organization has enough managers to meet most challenges.
- B. (2016, September 20). Mintzberg's Management Roles - Boundless Open Textbook. Retrieved July 28, 2017, from https://www.boundless.com/management/textbooks/boundless-management-textbook/introduction-to-management-1/additional-roles-and-skills-of-managers-20/mintzberg-s-management-roles-127-605/ ↵
- Ibid. ↵
- Pittsburghers Protest Uber As CEO Reacts To Public Outcry. (n.d.). Retrieved July 28, 2017, from http://pittsburgh.cbslocal.com/2017/02/04/pittsburgh-uber-protest/ ↵
- Mintzberg's Management Roles - Boundless Open Textbook. ↵
Contributors and Attributions
- Management Roles. Authored by : John and Lynn Bruton. Published by Lumen Learning. License : CC BY: Attribution
- Modification of Image: Roles and functions of managers in a top-down organizational structure. Authored by : JMcIntyre; Modification by Lumen Learning. Located at : http://jmcintyre.wikispaces.com/bbi2o_functions_of_business_management . License : CC BY-SA: Attribution-ShareAlike


24.3: Ecology of Fungi
Skills to Develop
- Describe the role of fungi in the ecosystem
- Describe mutualistic relationships of fungi with plant roots and photosynthetic organisms
- Describe the beneficial relationship between some fungi and insects
Fungi play a crucial role in the balance of ecosystems. They colonize most habitats on Earth, preferring dark, moist conditions. They can thrive in seemingly hostile environments, such as the tundra, thanks to a most successful symbiosis with photosynthetic organisms like algae to produce lichens. Fungi are not obvious in the way large animals or tall trees appear. Yet, like bacteria, they are the major decomposers of nature. With their versatile metabolism, fungi break down organic matter, which would not otherwise be recycled.
Habitats
Although fungi are primarily associated with humid and cool environments that provide a supply of organic matter, they colonize a surprising diversity of habitats, from seawater to human skin and mucous membranes. Chytrids are found primarily in aquatic environments. Other fungi, such as Coccidioides immitis , which causes pneumonia when its spores are inhaled, thrive in the dry and sandy soil of the southwestern United States. Fungi that parasitize coral reefs live in the ocean. However, most members of the Kingdom Fungi grow on the forest floor, where the dark and damp environment is rich in decaying debris from plants and animals. In these environments, fungi play a major role as decomposers and recyclers, making it possible for members of the other kingdoms to be supplied with nutrients and live.
Decomposers and Recyclers
The food web would be incomplete without organisms that decompose organic matter (Figure \(\PageIndex{1}\)). Some elements—such as nitrogen and phosphorus—are required in large quantities by biological systems, and yet are not abundant in the environment. The action of fungi releases these elements from decaying matter, making them available to other living organisms. Trace elements present in low amounts in many habitats are essential for growth, and would remain tied up in rotting organic matter if fungi and bacteria did not return them to the environment via their metabolic activity.
The ability of fungi to degrade many large and insoluble molecules is due to their mode of nutrition. As seen earlier, digestion precedes ingestion. Fungi produce a variety of exoenzymes to digest nutrients. The enzymes are either released into the substrate or remain bound to the outside of the fungal cell wall. Large molecules are broken down into small molecules, which are transported into the cell by a system of protein carriers embedded in the cell membrane. Because the movement of small molecules and enzymes is dependent on the presence of water, active growth depends on a relatively high percentage of moisture in the environment.
As saprobes, fungi help maintain a sustainable ecosystem for the animals and plants that share the same habitat. In addition to replenishing the environment with nutrients, fungi interact directly with other organisms in beneficial, and sometimes damaging, ways (Figure \(\PageIndex{2}\)).
Mutualistic Relationships
Symbiosis is the ecological interaction between two organisms that live together. The definition does not describe the quality of the interaction. When both members of the association benefit, the symbiotic relationship is called mutualistic. Fungi form mutualistic associations with many types of organisms, including cyanobacteria, algae, plants, and animals.
Fungus/Plant Mutualism
One of the most remarkable associations between fungi and plants is the establishment of mycorrhizae. Mycorrhiza , which comes from the Greek words myco meaning fungus and rhizo meaning root, refers to the association between vascular plant roots and their symbiotic fungi. Somewhere between 80 and 90 percent of all plant species have mycorrhizal partners. In a mycorrhizal association, the fungal mycelia use their extensive network of hyphae and large surface area in contact with the soil to channel water and minerals from the soil into the plant. In exchange, the plant supplies the products of photosynthesis to fuel the metabolism of the fungus.
There are a number of types of mycorrhizae. Ectomycorrhizae (“outside” mycorrhiza) depend on fungi enveloping the roots in a sheath (called a mantle) and a Hartig net of hyphae that extends into the roots between cells (Figure 24.3.3). The fungal partner can belong to the Ascomycota, Basidiomycota or Zygomycota. In a second type, the Glomeromycete fungi form vesicular–arbuscular interactions with arbuscular mycorrhiza (sometimes called endomycorrhizae). In these mycorrhiza, the fungi form arbuscules that penetrate root cells and are the site of the metabolic exchanges between the fungus and the host plant (Figure \(\PageIndex{3}\) and Figure \(\PageIndex{4}\)). The arbuscules (from the Latin for little trees) have a shrub-like appearance. Orchids rely on a third type of mycorrhiza. Orchids are epiphytes that form small seeds without much storage to sustain germination and growth. Their seeds will not germinate without a mycorrhizal partner (usually a Basidiomycete). After nutrients in the seed are depleted, fungal symbionts support the growth of the orchid by providing necessary carbohydrates and minerals. Some orchids continue to be mycorrhizal throughout their lifecycle.
Art Connection
If symbiotic fungi are absent from the soil, what impact do you think this would have on plant growth?
Other examples of fungus–plant mutualism include the endophytes: fungi that live inside tissue without damaging the host plant. Endophytes release toxins that repel herbivores, or confer resistance to environmental stress factors, such as infection by microorganisms, drought, or heavy metals in soil.
Evolution Connection: Coevolution of Land Plants and Mycorrhizae
Mycorrhizae are the mutually beneficial symbiotic association between roots of vascular plants and fungi. A well-accepted theory proposes that fungi were instrumental in the evolution of the root system in plants and contributed to the success of Angiosperms. The bryophytes (mosses and liverworts), which are considered the most primitive plants and the first to survive on dry land, do not have a true root system; some have vesicular–arbuscular mycorrhizae and some do not. They depend on a simple rhizoid (an underground organ) and cannot survive in dry areas. True roots appeared in vascular plants. Vascular plants that developed a system of thin extensions from the rhizoids (found in mosses) are thought to have had a selective advantage because they had a greater surface area of contact with the fungal partners than the mosses and liverworts, thus availing themselves of more nutrients in the ground.
Fossil records indicate that fungi preceded plants on dry land. The first association between fungi and photosynthetic organisms on land involved moss-like plants and endophytes. These early associations developed before roots appeared in plants. Slowly, the benefits of the endophyte and rhizoid interactions for both partners led to present-day mycorrhizae; up to about 90 percent of today’s vascular plants have associations with fungi in their rhizosphere. The fungi involved in mycorrhizae display many characteristics of primitive fungi; they produce simple spores, show little diversification, do not have a sexual reproductive cycle, and cannot live outside of a mycorrhizal association. The plants benefited from the association because mycorrhizae allowed them to move into new habitats because of increased uptake of nutrients, and this gave them a selective advantage over plants that did not establish symbiotic relationships.
Lichens
Lichens display a range of colors and textures (Figure \(\PageIndex{5}\)) and can survive in the most unusual and hostile habitats. They cover rocks, gravestones, tree bark, and the ground in the tundra where plant roots cannot penetrate. Lichens can survive extended periods of drought, when they become completely desiccated, and then rapidly become active once water is available again.
Lichens are not a single organism, but rather an example of a mutualism, in which a fungus (usually a member of the Ascomycota or Basidiomycota phyla) lives in close contact with a photosynthetic organism (a eukaryotic alga or a prokaryotic cyanobacterium) (Figure \(\PageIndex{6}\)). Generally, neither the fungus nor the photosynthetic organism can survive alone outside of the symbiotic relationship. The body of a lichen, referred to as a thallus, is formed of hyphae wrapped around the photosynthetic partner. The photosynthetic organism provides carbon and energy in the form of carbohydrates. Some cyanobacteria fix nitrogen from the atmosphere, contributing nitrogenous compounds to the association. In return, the fungus supplies minerals and protection from dryness and excessive light by encasing the algae in its mycelium. The fungus also attaches the symbiotic organism to the substrate.
The thallus of lichens grows very slowly, expanding its diameter a few millimeters per year. Both the fungus and the alga participate in the formation of dispersal units for reproduction. Lichens produce soredia , clusters of algal cells surrounded by mycelia. Soredia are dispersed by wind and water and form new lichens.
Lichens are extremely sensitive to air pollution, especially to abnormal levels of nitrogen and sulfur. The U.S. Forest Service and National Park Service can monitor air quality by measuring the relative abundance and health of the lichen population in an area. Lichens fulfill many ecological roles. Caribou and reindeer eat lichens, and they provide cover for small invertebrates that hide in the mycelium. In the production of textiles, weavers used lichens to dye wool for many centuries until the advent of synthetic dyes.
Link to Learning
Lichens are used to monitor the quality of air. Read more on this site from the United States Forest Service.
Fungus/Animal Mutualism
Fungi have evolved mutualisms with numerous insects in Phylum Arthropoda: jointed, legged invertebrates. Arthropods depend on the fungus for protection from predators and pathogens, while the fungus obtains nutrients and a way to disseminate spores into new environments. The association between species of Basidiomycota and scale insects is one example. The fungal mycelium covers and protects the insect colonies. The scale insects foster a flow of nutrients from the parasitized plant to the fungus. In a second example, leaf-cutting ants of Central and South America literally farm fungi. They cut disks of leaves from plants and pile them up in gardens (Figure \(\PageIndex{7}\)). Fungi are cultivated in these disk gardens, digesting the cellulose in the leaves that the ants cannot break down. Once smaller sugar molecules are produced and consumed by the fungi, the fungi in turn become a meal for the ants. The insects also patrol their garden, preying on competing fungi. Both ants and fungi benefit from the association. The fungus receives a steady supply of leaves and freedom from competition, while the ants feed on the fungi they cultivate.
Fungivores
Animal dispersal is important for some fungi because an animal may carry spores considerable distances from the source. Fungal spores are rarely completely degraded in the gastrointestinal tract of an animal, and many are able to germinate when they are passed in the feces. Some dung fungi actually require passage through the digestive system of herbivores to complete their lifecycle. The black truffle—a prized gourmet delicacy—is the fruiting body of an underground mushroom. Almost all truffles are ectomycorrhizal, and are usually found in close association with trees. Animals eat truffles and disperse the spores. In Italy and France, truffle hunters use female pigs to sniff out truffles. Female pigs are attracted to truffles because the fungus releases a volatile compound closely related to a pheromone produced by male pigs.
Summary
Fungi have colonized nearly all environments on Earth, but are frequently found in cool, dark, moist places with a supply of decaying material. Fungi are saprobes that decompose organic matter. Many successful mutualistic relationships involve a fungus and another organism. Many fungi establish complex mycorrhizal associations with the roots of plants. Some ants farm fungi as a supply of food.  The photosynthetic organism provides energy derived from light and carbohydrates, while the fungus supplies minerals and protection. Some animals that consume fungi help disseminate spores over long distances.
Art Connections
Figure \(\PageIndex{3}\): If symbiotic fungi are absent from the soil, what impact do you think this would have on plant growth?
- Answer
-
Without mycorrhiza, plants cannot absorb adequate nutrients, which stunts their growth. Addition of fungal spores to sterile soil can alleviate this problem.
Glossary
- arbuscular mycorrhiza
- mycorrhizal association in which the fungal hyphae enter the root cells and form extensive networks
- ectomycorrhiza
- mycorrhizal fungi that surround the roots with a mantle and have a Hartig net that extends into the roots between cells
- lichen
- close association of a fungus with a photosynthetic alga or bacterium that benefits both partners
- mycorrhiza
- mutualistic association between fungi and vascular plant roots
- soredia
- clusters of algal cells and mycelia that allow lichens to propagate


3.2A: Microscopy
- Compare and contrast light and electron microscopy.
Cells vary in size. With few exceptions, individual cells cannot be seen with the naked eye, so scientists use microscopes (micro- = “small”; -scope = “to look at”) to study them. A microscope is an instrument that magnifies an object. Most photographs of cells are taken with a microscope; these images can also be called micrographs.
The optics of a microscope’s lenses change the orientation of the image that the user sees. A specimen that is right-side up and facing right on the microscope slide will appear upside-down and facing left when viewed through a microscope, and vice versa. Similarly, if the slide is moved left while looking through the microscope, it will appear to move right, and if moved down, it will seem to move up. This occurs because microscopes use two sets of lenses to magnify the image. Because of the manner by which light travels through the lenses, this system of two lenses produces an inverted image (binocular, or dissecting microscopes, work in a similar manner, but they include an additional magnification system that makes the final image appear to be upright).
Light Microscopes
To give you a sense of cell size, a typical human red blood cell is about eight millionths of a meter or eight micrometers (abbreviated as eight μm) in diameter; the head of a pin of is about two thousandths of a meter (two mm) in diameter. That means about 250 red blood cells could fit on the head of a pin.
Most student microscopes are classified as light microscopes. Visible light passes and is bent through the lens system to enable the user to see the specimen. Light microscopes are advantageous for viewing living organisms, but since individual cells are generally transparent, their components are not distinguishable unless they are colored with special stains. Staining, however, usually kills the cells.
Light microscopes, commonly used in undergraduate college laboratories, magnify up to approximately 400 times. Two parameters that are important in microscopy are magnification and resolving power. Magnification is the process of enlarging an object in appearance. Resolving power is the ability of a microscope to distinguish two adjacent structures as separate: the higher the resolution, the better the clarity and detail of the image. When oil immersion lenses are used for the study of small objects, magnification is usually increased to 1,000 times. In order to gain a better understanding of cellular structure and function, scientists typically use electron microscopes.
Electron Microscopes
In contrast to light microscopes, electron microscopes use a beam of electrons instead of a beam of light. Not only does this allow for higher magnification and, thus, more detail, it also provides higher resolving power. The method used to prepare the specimen for viewing with an electron microscope kills the specimen. Electrons have short wavelengths (shorter than photons) that move best in a vacuum, so living cells cannot be viewed with an electron microscope.
In a scanning electron microscope, a beam of electrons moves back and forth across a cell’s surface, creating details of cell surface characteristics. In a transmission electron microscope, the electron beam penetrates the cell and provides details of a cell’s internal structures. As you might imagine, electron microscopes are significantly more bulky and expensive than light microscopes.
Key Points
- Light microscopes allow for magnification of an object approximately up to 400-1000 times depending on whether the high power or oil immersion objective is used.
- Light microscopes use visible light which passes and bends through the lens system.
- Electron microscopes use a beam of electrons, opposed to visible light, for magnification.
- Electron microscopes allow for higher magnification in comparison to a light microscope thus, allowing for visualization of cell internal structures.
Key Terms
- resolution : The degree of fineness with which an image can be recorded or produced, often expressed as the number of pixels per unit of length (typically an inch).
- electron : The subatomic particle having a negative charge and orbiting the nucleus; the flow of electrons in a conductor constitutes electricity.


19.4: Verifications
Suppose we need to verify that a given configuration is defined by a certain property. Is it possible to do this task by a geometric construction with given tools? We assume that we can verify that two constructed points coincide.
Evidently if a configuration is constructible, then it is verifiable — simply repeat the construction and check if the result is the same. Some nonconstuctable configuration can be verifiable. For example, it does not pose a problem to verify that the given angle is trisected while it is impossible to trisect a given angle with ruler and compass. A regular 7-gon provides another example of that type — it is easy to verify, while Gauss–Wantzel theorem states that it is impossible to construct with ruler and compass.
Since we did not prove the impossibility of angle trisection and Gauss–Wantzel theorem, the following example might be more satisfactory. It is based on Exercise 19.3.2 which states that it is impossible to construct an equilateral with set-square only.
Make a set-square construction verifying that a given triangle is equilateral.
- Hint
-
Observe that three perpendiculars on the diagram meet at one point if and only if the triangle is isosceles. Use this observation couple of times to verify that the given triangle is equilateral.
This observation leads to a source of impossible constructions in a stronger sense — those that are not even not verifiable.
The following example is closely related to Exercise 10.3.2 . Recall that a circumtool produces a circle passing thru any given three points or a line if all three points lie on one line.
Show that with a circumtool only, it is impossible to verify that a given point is the center of a given circle \(\Gamma\) . In particular it is impossible to construct the center with a circumtool only.
In geometric constructions, we allow to choose some free points, say any point on the plane, or a point on a constructed line, or a point that does not lie on a constructed line, or a point on a given line that does not lie on a given circle, and so on.
In principle, when you make such a free choice it is possible to make a right construction by accident. Nevertheless, we do not accept such a coincidence as true construction; we say that a construction produces the center if it produces it for any free choices.
- Solution
-
Arguing by contradiction, assume we have a verifying construction.
Apply an inversion in a circle perpendicular to \(\Gamma\) to the whole construction. According to Corollary 10.5.1 , the circle \(\Gamma\) maps to itself. Since the inversion sends a circline to a circline, we get that the whole construction is mapped to an equivalent construction; that is, a constriction with a different choice of free points.
According to Exercise 10.3.1 , the inversion sends the center of \(\Gamma\) to another point. However this construction claims that this another point is the center — a contradiction.
A similar example of impossible constructions for a ruler and a parallel tool is given in Exercise 14.2.4 .
Let us discuss another example for a ruler-only construction. Note that ruler-only constructions are invariant with respect to the projective transformations. In particular, to solve the following exercise, it is sufficient to construct a projective transformation that fixes two points and moves their midpoint.
Show that there is no ruler-only construction verifying that a given point is a midpoint of a given segment. In particular it is impossible to construct the midpoint only with a ruler.
- Hint
-
Consider the perspective projection \((x,y) \mapsto (\tfrac{1}{x}, \tfrac{y}{x})\). Let \(A = (1, 1), B = (3, 1)\), and \(M = (2, 1)\). Note that \(M\) is the midpoint of \([AB]\).
Their images are \(A' = (1, 1)\), \(B' = (\tfrac{1}{3}, \tfrac{1}{3})\), and \(M' = (\tfrac{1}{2}, \tfrac{1}{2})\). Clearly, \(M'\) is note the midpoint of \([A'B']\).
The following theorem is a stronger version of the exercise above.
There is no ruler-only construction verifying that a given point is the center of a given circle. In particular it is impossible to construct the center only with a ruler.
The proof uses the construction in Theorem 16.3.2 .
- Sketch of the proof
-
The same argument as in the problem above shows that it is sufficient to construct a projective transformation that sends the given circle \(\Gamma\) to a circle \(\Gamma'\) such that the center of \(\Gamma'\) is not the image of the center of \(\Gamma\) .
Choose a circle \(\Gamma\) that lies in the plane \(\Pi\) in the Euclidean space. By Theorem 16.3.1 , the inverse of a circle in a sphere is a circle or a line. Fix a sphere \(\Sigma\) with the center \(O\) so that the inversion \(\Gamma'\) of \(\Gamma\) is a circle and the plane \(\Pi'\) containing \(\Gamma'\) is not parallel to \(\Pi\) ; any sphere \(\Sigma\) in a general position will do.
Let \(Z\) and \(Z'\) denote the centers of \(\Gamma\) and \(\Gamma'\) . Note that \(Z'\notin(OZ)\) . It follows that the perspective projection \(\Pi\to \Pi'\) with center at \(O\) sends \(\Gamma\) to \(\Gamma'\) , but \(Z'\) is not the image of \(Z\) .


1.3: Module 3- World Coordinate System
Module 3: World Coordinate System
Learning Outcomes
When you have completed this module, you will be able to:
- Describe the World Coordinate System, the UCS icon, and the right-hand rule.
- Draw 3D models with the UCS located at the World Coordinate System.
The World Coordinate System
AutoCAD has two distinct three-dimensional coordinate systems: the World Coordinate System (WCS) and the User Coordinate System (UCS). The World Coordinate System is permanently located at the absolute coordinates X0Y0Z0. It is a fixed coordinate system which can never be moved. The WCS is normally not used to construct models. You will be using it in this module to construct models as learning tool only.
The User Coordinate System (UCS) is the coordinate system that is used to construct 3D models. The UCS can be placed exactly at the WCS or at any location in 3D space. In this module, model will be constructed with the UCS located at the WCS. It is essential to be able to locate and orientate the UCS to construct most models. This is taught in Module 4 and 5.
The UCS Icon
Figure 3-1 shows the UCS icon and the positive X, Y and Z directions indicated by the UCS icon. When constructing models, it is very important to know which direction is positive and negative on all three axis.
When the UCS is located at the World Coordinate System, it will display a small square at the origin as can be seen in Figure 3-2. If it is located at any other location, it will display as shown in Figure 3-3.
The Right-Hand Rule
Even though the 3D UCS icon indicates the positive Z direction, it is important to know how it is obtained. AutoCAD uses the right-hand rule to find the positive Z direction. See Figure 3-4. To use the right-hand rule, you must first know the positive X and Y directions of the current UCS.
Using your right hand, point your thumb in the direction of the positive X axis. Extend your index finger in the direction of the positive Y axis. The middle finger indicates the direction of the positive Z axis. By rotating your hand, the X, Y and Z axes will rotate to change the UCS location and orientation. It is important to be able to visualize how and where to move the UCS as you construct more complicated models.
Drawing with theZ Coordinate
While drawing in 2D, you only had to worry about entering the X and Y coordinates. Since the Z coordinate was omitted, AutoCAD used the default value of zero. When drawing in 3D, you must add the Z value in some coordinate input. For example, to enter the coordinates X2Y3Z4, enter 2,3,4 if it is an absolute coordinate and @2,3,4 if it is a relative coordinate.
Absolute X0Y0Z0
The absolute coordinate 0,0,0 is the origin of the World Coordinate System. This is the same location used in 2D when only 0,0 was entered. This is an important coordinate location as everything drawn in model space relates back to this location. Keep this in mind when drawing all future models. It is especially important when constructing models that relate to real world locations. For example, when drawing a map, X0Y0Z0 is located at the equator and your model must be drawn in relation to that location.
WORK ALONG: Drawing 3D Wireframe Models with the UCS Located at the WCS
Step 1
Using the NEW command, start a new drawing using the template: 3D Layout English .
Step 2
Save the drawing with the name: AutoCAD 3D Workalong 03-1 . (Figure Step 2)
Step 3
Set the current view to SE Isometric. (Figure Step 3)
Step 4
Ensure that the UCS Icon is enabled (On) and the Origin is enabled as shown in Module 1 WORKALONG: Using the UCSICON, VIEW, and 3DFORBIT Commands.
Step 5
Set layer: Model as the current layer. Enter the LINE command, as shown below, to draw the lines to start the construction of the model. (Figure Step 5)
Command: LINE
Specify first point: 0,0,0
Specify next point or [Undo]: @2,0
(Since you are working at Z zero, you can omit the Z value.)
Specify next point or [Undo]: @2,2
Specify next point or [Close/Undo]: @4,0
Specify next point or [Close/Undo]: @0,2
Specify next point or [Close/Undo]: @-8,0
Specify next point or [Close/Undo]: C
Command:
(Draw the object that is located on the XY axis as you did in 2D.)
Step 6
Using the OFFSET command, offset the two lines 1.5 units as shown in the figure. Change the layer properties of the two lines to layer: Construction. (Figure Step 6)
Step 7
Use the CIRCLE command to draw a 2 diameter circle with its centre located at the intersection of the two construction lines. (Figure Step 7)
Step 8
Freeze layer: Construction . Enter the COPY command, as shown below, and copy the three lines and the circle 4 units in the positive Z direction. (Figure Step 8).
Command: COPY
Select objects:
(Select the three lines and the circle as shown in Figure Step 8.)
Select objects:
Specify base point or displacement, or [Multiple]: 0,0,0
Specify second point of displacement or <use first point as displacement>: @0,0,4
(Copy the 4 objects 4 units in the positive Z direction. Looking at the UCS or using the right- hand rule will indicated if it is a positive or negative direction.)
Command:
Step 9
Using the 3DFORBIT command, orbit the model slightly. (Figure Step 9)
Step 10
Using the COPY command, copy the 2 lines 2 units in the positive Z directions. (Figure Step 10)
Step 11
Use the LINE command to draw six lines between the ends of the existing lines. Ensure that you snap to the ends of the lines. (Figure Step 11)
Step 12
Using the COPY command, copy the short line located at the right end of the model two times. Ensure that you use snap mode to locate the lines exactly. (Figure Step 12)
Step 13
Draw three lines between the ends of the existing lines. Ensure to snap to the ends of the existing lines. (Figure Step 13)
Step 14
Using the VIEW command, save the current view with the name: Working Isometric. (Figure Step 14)
Step 15
Change the current view to SE Isometric. (Figure Step 15)
Step 16
Enter the UNITS command. In the Units dialogue box, set the Insertion Units to Inches. Insert the key: AutoCAD 3D Workalong 03-1 . It will overlay the model with a magenta model. (Figure Step 16)
Step 17
Save and close the drawing.
WORK ALONG: Drawing 3D Wireframe Models With the UCS Located at the WCS
Step 1
Using the NEW command, start a new drawing using the template: 3D Layout Metric.
Step 2
Save the drawing with the name: AutoCAD 3D Workalong 03-2 . (Figure Step 2)
Step 3
Set the current view to SE Isometric. (Figure Step 3)
Step 4
Ensure that the UCS Icon is enabled (On) and the Origin is enabled as shown in Module 1, WORKALONG: Using the UCSICON, VIEW, and 3DFORBIT Commands.
Step 5
Set layer: Model as the current layer. Draw the shape of the top of the object. Use the ARRAY command to speed up the construction. (Figure Step 5)
Step 6
Using the COPY command, as shown below, copy all of the objects 10 units in the negative Z direction. (Figure Step 6)
Command: COPY
Select objects:
(Select all objects.)
Select objects:
Specify base point or displacement, or [Multiple]: 0,0,0
Specify second point of displacement or <use first point as displacement>: @0,0,-10
Command:
Step 7
Using the 3DFORBIT command, orbit the model slightly until it appears similar to the figure. (Figure Step 7)
Step 8
Draw the vertical lines by snapping to the endpoints to complete the wireframe model. (Figure Step 8)
Step 9
Using the VIEW command, save the current view with the name: Working Isometric . (Figure Step 9)
Step 10
Change the view to SE Isometric. (Figure Step 10)
Step 11
Enter the UNITS command. In the Units dialogue box, set the Insertion Units to Millimeters. Insert the key:
AutoCAD 3D Workalong 03-2 . It will overlay the model with a magenta model. (Figure Step 11)
Step 12
Save and close the drawing.
Key Principles
Key Principles in Module 3
- AutoCAD has two distinct three dimensional coordinate systems: the World Coordinate System (WCS) and the User Coordinate System (UCS).
- The World Coordinate System is permanently located at the absolute coordinates It is a fixed coordinate system which can never be moved. The WCS is normally not used to construct models.
- The User Coordinate System is the coordinate system that is normally used to construct 3D The UCS can be placed exactly at the WCS or at any location in 3D space.
- AutoCAD uses the right-hand rule to find the positive Z To use the right-hand rule, you must first know the positive X and Y directions of the current UCS. Using your right hand, point the thumb in the direction of the positive X axis. Extend your index finger in the direction of the positive Y axis. Your middle finger indicates the direction of the positive Z axis.
- The absolute coordinate 0,0,0 is the origin of the world coordinate This is the same point used when drawing in 2D when 0,0 was entered. This is an important coordinate location as everything drawn in model space relates back to this location.
Lab Exercise 3-1
Time allowed: 45 minutes.
| Drawing Name | Template | Units |
|---|---|---|
| AutoCAD 3D Lab 03-1 | 3D Layout English | Inches |
Step 1
Save and name the drawing: AutoCAD 3D Lab 03-1 .
Step 2
Draw all construction objects on layer: Construction and model objects on layer: Model .
Step 3
Draw a wireframe model of the object shown in the figure. (Figure Step 3A and 3B)
Step 4
Start your model with the current view SE Isometric. If required, orbit it slightly with 3DFORBIT to help the line of sight.
Step 5
Save the isometric working view with the name: Working Isometric .
Step 6
When complete, freeze layer: Construction.
Step 7
Enter the UNITS command. In the Units dialogue box, set the Insertion Units to Inches.
Step 8
Check your drawing with the key. The key name is the same as the drawing name.
Hint 1
Lab Exercise 3-2
Time allowed: 45 minutes.
| Drawing Name | Template | Units |
|---|---|---|
| AutoCAD 3D Lab 03-2 | 3D Layout English | Millimeters |
Step 1
Save the drawing with the name: AutoCAD 3D Lab 03-2 .
Step 2
Draw all construction objects on layer: Construction and all model objects on layer: Model .
Step 3
Draw a wireframe model of the object shown in the figure. (Figure Step 3A, 3B, 3C, and 3D)
Step 4
Start your model with the current view SE Isometric. If required, orbit it slightly with 3DFORBIT to help the line of sight.
Step 5
Save the isometric working view with the name: Working Isometric .
Step 6
When complete, freeze layer: Construction .
Step 7
Enter the UNITS command. In the Units dialogue box, set the Insertion Units to Millimeters.
Step 8
Check your drawing with the key. The key name is the same as the drawing name.