Question:
Which statement best compares single-celled and multi-celled organisms?
OPTIONS:
- Tissues in a single-celled organism are like the cells in a multi-celled organism.
- The nucleus in a single-celled organism is like the skin of a multi-celled organism.
- Organelles in a single-celled organism are like the organs in a multi-celled organism.
- The cytoplasm in a single-celled organism is like the nervous system in a multi-celled organism.
Answer:
Organelles in a single-celled organism are like the organs in a multi-celled organism.
Question:
The burning of fossil fuels has increased the carbon dioxide content of the atmosphere. What is a possible effect that the increased amount of carbon dioxide is likely to have on our planet?
OPTIONS:
- A warmer climate
- A cooler climate
- Lower relative humidity
- More ozone in the atmosphere
Answer:
A warmer climate
Question:
In a comparison of metals to nonmetals, metals tend to have
OPTIONS:
- lower melting points and greater conductivity than nonmetals.
- lower conductivity and lower density than nonmetals.
- higher density and lower melting points than nonmetals.
- greater conductivity and higher melting points than nonmetals.
Answer:
greater conductivity and higher melting points than nonmetals.
Question:
In a desert environment, cactus wrens often build their nests in cholla cacti to avoid predators. This behavior does not hurt the cacti. Which type of relationship do cactus wrens and cholla cacti demonstrate?
OPTIONS:
- competitive
- commensalism
- mutualism
- parasitism
Answer:

commensalism