What must happen for speciation to occur?
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a. gene flow must increase.
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b. a population must be isolated in some way.
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c. all alleles in the population must become fixed.
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d. asexual reproduction must occur.

Which part of the cell is affected by the movement of molecules through diffusion, osmosis and active transport?

The two main stages of cell division are called

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.