Populations evolve for many reasons. suppose there is a population of plants that have either purple flowers or white flowers, and the allele for purple flowers is dominant. this means that plants with two purple alleles have purple flowers. plants with one purple allele and one white allele also have purple flowers. only plants with two white alleles have white flowers. for each event or condition described below, answer the following questions. a. which mechanism of evolution is at work? b. how does this event affect the population's gene pool? c. do the frequencies of the two alleles change, and if so, how?

Consider an organism that is eukaryotic, found in both unicellular and multicellular forms, may resemble a plant but is not photosynthetic, has chitin in its cell walls, and absorbs organic nutrients from decomposing material in the environment. this organism would be classified as which of the following types of organisms? a. fungib. protozoac. bacteriad. archaea

What initially causes a nerve impulse? release of enzymes out of the neuron movement of chemicals into the dendrites of the neuron pathogens attacking the dendrites of the neuron red blood cells bathing the neuron

Refer to this portion of a dichotomous key for fish identification to answer the question. 1. (a) has a single dorsal fin ® 5 (b) has a double dorsal fin ® 2 2. (a) one fin is spiny, the other is smooth ® 3 (b) one fin is not spiny or smooth ® 4 5. (a) has small fin on back near tail ® 6 (b) has no fin on back near tail ® 7 6. (a) has barbs near the mouth ® catfish (b) does not have barbs near the mouth ® 10 7. (a) tail is asymmetrical ® 8 (b) tail is symmetrical ® 9 10. (a) scales are small ® trout (b) scales are large ® whitefish what is the next step to complete to identify a fish that has a single dorsal fin, no fin on the back near the tail, and no barbs near the mouth? step 2 step 5 step 7 step 10