Question: Q: Organisms that lack both a nucleus and membrane-bound organelles are known as what, in general?   Read this paragraph and choose the correct option from the provided answers:  Two of the three domains—Bacteria and Archaea—are prokaryotic, meaning that they lack both a nucleus and true membrane-bound organelles. However, they are now considered, on the basis of membrane structure and rRNA, to be as different from each other as they are from the third domain, the Eukarya. Prokaryotes were the first inhabitants on Earth, perhaps appearing approximately 3.9 billion years ago. Today they are ubiquitous—inhabiting the harshest environments on the planet, from boiling hot springs to permanently frozen environments in Antarctica, as well as more benign environments such as compost heaps, soils, ocean waters, and the guts of animals (including humans). The Eukarya include the familiar kingdoms of animals, plants, and fungi. They also include a diverse group of kingdoms formerly grouped together as protists.   Choices:  - photosynthetic  - barren  - trophic  - prokaryotic   A:
Answer: prokaryotic

Question: Q: The number of electron pairs that hold two atoms together is called?   Read this paragraph and choose the correct option from the provided answers:  Summary Bond order is the number of electron pairs that hold two atoms together. Single bonds have a bond order of one, and multiple bonds with bond orders of two (a double bond) and three (a triple bond) are quite common. In closely related compounds with bonds between the same kinds of atoms, the bond with the highest bond order is both the shortest and the strongest. In bonds with the same bond order between different atoms, trends are observed that, with few exceptions, result in the strongest single bonds being formed between the smallest atoms. Tabulated values of average bond energies can be used to calculate the enthalpy change of many chemical reactions. If the bonds in the products are stronger than those in the reactants, the reaction is exothermic and vice versa. Saylor URL: http://www. saylor. org/books.   Choices:  - nuclear order  - proton order  - electron order  - bond order   A:
Answer: bond order

Question: Q: When cardiac muscle contracts, the heart does what?   Read this paragraph and choose the correct option from the provided answers:  Cardiac muscle is found only in the walls of the heart. It is striated, or striped, because its muscle fibers are arranged in bundles. Contractions of cardiac muscle are involuntary. This means that they are not under conscious control. When cardiac muscle contracts, the heart beats and pumps blood.   Choices:  - cardiac arrest  - irregular heartbeat  - heart murmur  - pumps blood   A:
Answer:
pumps blood