Jellyfish, earthworms, grasshoppers, and humans are all classified in the same

a. kingdom

b. phylum

c. class

d. species

Next pretest: evolution select the correct answer in a laboratory population of flies, the female flies are gray and the males are yellowish gray. biologists observed that all the male flies had an equal chance for reproduction, but the male flies with the brightest colors were more likely to successfully reproduce. what phenomenon could explain such a change? a sexual selection b. disruptive selection c. stabilizing selection d. directional selection

For the strategies below, decide whether they are best described as demand-side solutions or supply-side solutions to meeting human needs for fresh water. remember that a demand-side solution reduces demand for fresh water, whereas a supply-side solution increases the supply of fresh water. (a) damming a river to create a reservoir (b) desalinating seawater (c) a nation invading a neighboring country to access their rivers (d) raising water prices for consumers and businesses (e) providing tax breaks for companies that use less water (f) replacing inefficient irrigation with more-efficient drip irrigation to grow crops (g) requiring low-flow showerheads in all new homes

Researchers studying a small milkweed population note that some plants produce a toxin and other plants do not. they identify the gene responsible for toxin production. the dominant allele (t) codes for an enzyme that makes the toxin, and the recessive allele (t) codes for a nonfunctional enzyme that cannot produce the toxin. heterozygotes produce an intermediate amount of toxin. the genotypes of all individuals in the population are determined (see chart) and used to determine the actual allele frequencies in the population. is this population in hardy-weinberg equilibrium? a) yes. b) no; there are more homozygotes than expected. c) no; there are more heterozygotes than expected. d) more information is needed to answer this question.