Answer the following question given this paragraph: Evidence from the fossil record can be combined with data from molecular clocks. A molecular clock uses DNA sequences (or the proteins they encode) to estimate relatedness among species. Molecular clocks estimate the time in geologic history when related species diverged from a common ancestor. Molecular clocks are based on the assumption that mutations accumulate through time at a steady average rate for a given region of DNA. Species that have accumulated greater differences in their DNA sequences are assumed to have diverged from their common ancestor in the more distant past. Molecular clocks based on different regions of DNA may be used together for more accuracy. Q: Species that have diverged from their common ancestors have greater differences in what? Choices: - life span - cell structure - immunology - dna sequence A:
dna sequence
Answer the following question given this paragraph: Q: What's the name for a cluster of genes, where one promoter serves adjacent genes? Choices: - nucleus - proton - plasma - opteron A:
opteron
Q: Answer the following question given this paragraph: 7. Compare and contrast the ecosystem concepts of niche and habitat. Q: Niche and habitat are concepts related to what broader term? Choices: - population - biome - community - ecosystem A:
A: ecosystem
Question: Answer the following question given this paragraph: The nuclei that are to the left or to the right of the band of stability are unstable and exhibit radioactivity. They change spontaneously (decay) into other nuclei that are either in, or closer to, the band of stability. These nuclear decay reactions convert one unstable isotope (or radioisotope) into another, more stable, isotope. We will discuss the nature and products of this radioactive decay in subsequent sections of this chapter. Several observations may be made regarding the relationship between the stability of a nucleus and its structure. Nuclei with even numbers of protons, neutrons, or both are more likely to be stable (see Table 21.1). Nuclei with. Q: Nuclei with even numbers of protons, neutrons, or both are more likely to be this? Choices: - ionic - solid - unstable - stable A:
Answer: stable
*Question*
Answer the following question given this paragraph: Have you ever experienced heartburn? Heartburn is actually a condition caused by stomach acid, rather something in your heart. The stomach produces HCl, which is a necessary component of digestion. However, excessive amounts of stomach acid can cause a great deal of discomfort. Various factors can cause the overproduction of acid, mostly related to the types (and amounts) of food and beverages that are being consumed. Caffeine and other oils in coffee (even decaf) will increase HCl production in the stomach. Smoking cigarettes and drinking alcohol also increase the formation of stomach acid. Q: What is a common condition caused by stomach acid? Choices: - arthritis - headache - sunburn - heartburn A:
**Answer**
heartburn
Q: Answer the following question given this paragraph: A piston having a certain pressure and volume (left piston) will have half the volume when its pressure is twice as much (right piston). One can also plot P versus V for a given amount of gas at a certain temperature; such a plot will look like the graph on the right. Boyle's law is an example of a second type of mathematical problem we see in chemistryone based on a mathematical formula. Tactics for working with mathematical formulas are different from tactics for working with conversion factors. First, most of the questions you will have to answer using formulas are word-type questions, so the first step is to identify what quantities are known and assign them to variables. Second, in most formulas, some mathematical rearrangements (i. , algebra) must be performed to solve for an unknown variable. The rule is that to find the value of the unknown variable, you must mathematically isolate the unknown variable by itself and in the numerator of one side of the equation. Finally, units must be consistent. For example, in Boyle's law there are two pressure variables; they must have the same unit. There are also two volume variables; they also must have the same unit. In most cases, it won't matter what the unit is, but the unit must be the same on both sides of the equation. Q: Boyle's law applies to matter which is in what state? Choices: - liquids - plasma - solids - gas A:
A: gas