How do predators affect population size in a food web?
i'm very confused of the two options, because some species of prey are becoming extinct. i'm not sure if i'm overthinking it or not. i'm picking between a and b.

a: they limit the size of populations of prey species.

b: they distribute populations in an ecosystem more evenly.

c: they increase the size of their prey populations.

d: they control the food supplies for all species.

Astudent observes a star from two positions of earth in its orbit, in summer and winter, and measures the change in the position of the star. which of these can be best calculated by this method?

Which of the following describes a negative feedback loop? when the heart rate is too high, the body sends hormones that continually increase the heart rate higher. when a pregnant woman is in labor, the body sends hormones that increase the intensity of contractions, which then increases the secretion of the same hormones. when blood sugar is too low, the body sends hormones that raise blood sugar until it reaches a typical level and hormone secretion slows. when a person is jogging, the body sends hormones that continually decrease the rate of oxygen supply to the legs.

Which units ate used to measure both velocity and speed? check all that apply