Two species of frogs are unable to mate with each other because they have different mating calls. this is an example of

a) genetic drift
b) geographic isolation
c) none of these
d) reproductive isolation

Apaleontologist finds a plant fossil that shows that the plant had seeds. what can the paleontologist conclude?

Which tool could you see a plant cell? a. a filter b. a microscope c. a microwave d. an electromagnet

When does a spring tide occur? question 9 options: they occur when the sun, moon, and earth are aligned. in spite of their name, these tides occur twice a year in the spring and fall. they occur on the date of the vernal equinox each year, no matter what stage the moon is in. this is why they are called spring tides. they occur when the sun, moon, and earth are at 45-degree angles from each other. this happens once every spring. they occur when the sun, moon, and earth are aligned. in spite of their name, these tides occur all year long.