Question 3 (2 points) Which of the following scenarios is an example of evolution by natural selection? (2 points)
1. A population of brown birds is nearly wiped out from a volcanic eruption. Most of the surviving birds are red, and after several
generations the population is predominantly red.
II. Lions, cheetahs, and other large predators prey on a population of antelope; the fastest antelope are most likely to escape
predators and live to reproduce.
III. Fertilizer runoff (phosphates) pollutes a nearby pond, where it stimulates over production of algae using up most of the pond's
oxygen and killing off the pond's larger fish,
оа
I only
Oь
Il only
ос
Ill only
Od
I and II only
Оe
II and III only

Amylase is an enzyme found in the human digestive system. why do you think it was important to keep the enzyme temperature above 37 degrees celsius (98.6 degrees f)? describe what might happen if the temperature decreased by 10 degrees celsius.

Atypical human cell is approximately 12.00 μm in diameter and enclosed by a membrane that is 5.000 nm thick. (a) what is the volume of the cell including the membrane? (b) what is the volume of the cell membrane? (c) what percent of the total volume does its membrane occupy? to simplify the calculations, model the cell as a sphere. enter your answers using four significant figures.

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