Q: Similarity in biochemicals, like the glucose used by virtually all living things for energy, provides evidence of what? Read this paragraph and choose the correct option from the provided answers: Virtually all living things use glucose for energy, but glucose is just one of many examples of biochemical compounds that are found in most or all living things. In fact the similarity in biochemical compounds between living things provides some of the best evidence for the evolution of species from common ancestors. A classic example is the biochemical compound called cytochrome c. It is found in all living organisms because it performs essential life functions. Only slight variations in the molecule exist between closely related species, as you can see in the Figure below . The molecule is identical in humans and their closest relatives, the chimpanzees. And even between humans and the single-celled tetrahymena (pictured in the Figure below ), the cytochrome c molecule is nearly 50 percent the same. Choices: - gravity - variation - DNA - evolution A:
evolution

(Question)
Q: When the maximum amount of solute has been dissolved in a given amount of solvent, we say that the solution is what? Read this paragraph and choose the correct option from the provided answers: When the maximum amount of solute has been dissolved in a given amount of solvent, we say that the solution is saturated with solute. When less than the maximum amount of solute is dissolved in a given amount of solute, the solution is unsaturated. These terms are also qualitative terms because each solute has its own solubility. A solution of 0.00019 g of AgCl per 100 g of H2O may be saturated, but with so little solute dissolved, it is also rather dilute. A solution of 36.1 g of NaCl in 100 g of H2O is also saturated but rather concentrated. Ideally, we need more precise ways of specifying the amount of solute in a solution. We will introduce such ways in Section 11.2 "Quantitative Units of Concentration". In some circumstances, it is possible to dissolve more than the maximum amount of a solute in a solution. Usually, this happens by heating the solvent, dissolving more solute than would normally dissolve at regular temperatures, and letting the solution cool down slowly and carefully. Such solutions are called supersaturated solutions and are not stable; given an opportunity (such as dropping a crystal of solute in the solution), the excess solute will precipitate from the solution. It should be obvious that some solutes dissolve in certain solvents but not others. NaCl, for example, dissolves in water but not in vegetable oil. Beeswax dissolves in liquid hexane but not water. What is it that makes a solute soluble in some solvents but not others? The answer is intermolecular interactions. The intermolecular interactions include London dispersion forces, dipole-dipole interactions, and hydrogen bonding (as described in Chapter 10 "Solids and Liquids"). From experimental studies, it has been determined that if molecules of a solute experience the Saylor URL: http://www. saylor. org/books. Choices: - blended - used - empty - saturated A:
(Answer)
saturated

Ques: Q: Human blood has a buffering system to minimize extreme changes in what? Read this paragraph and choose the correct option from the provided answers: Buffers work well only for limited amounts of added strong acid or base. Once either solute is all reacted, the solution is no longer a buffer, and rapid changes in pH may occur. We say that a buffer has a certain capacity. Buffers that have more solute dissolved in them to start with have larger capacities, as might be expected. Human blood has a buffering system to minimize extreme changes in pH. One buffer in blood is based on the presence of HCO3 and H2CO3 [H2CO3 is another way to write CO2(aq)]. With this buffer present, even if some stomach acid were to find its way directly into the bloodstream, the change in the pH of blood would be minimal. Inside many of the body's cells, there is a buffering system based on phosphate ions. Choices: - sodium level - calcium - ions - ph A:
Ans: ph

(Q).
Q: Helium-3 is produced by beta decay of a certain what? Read this paragraph and choose the correct option from the provided answers: helium-3 is produced by beta decay of a certain nuclide. Choices: - electron - quark - particle - nuclide A:
(A).
nuclide

Ques:Q: Which kinds of cells have nuclei and other membrane bound organelles? Read this paragraph and choose the correct option from the provided answers: Like the cells of all eukaryotes, animal cells have a nucleus and other membrane-bound organelles. Unlike the cells of eukaryotes in the Plant and Fungus Kingdoms, animal cells lack a cell wall. This gives animal cells flexibility. It lets them take on different shapes. This in turn allows them to become specialized for particular jobs. Choices: - lipids - monocytes - prokaryotes - eukaryotes A:

Ans:eukaryotes

Q: If both atoms are the same, they have the same electronegativity and share what type of bond? Read this paragraph and choose the correct option from the provided answers: Choices: - metabolic - ionic - isotopic covalent - nonpolar covalent A:
nonpolar covalent