c.midrib. The petiole is a stalk arising from the stem of the plant that connects the stem to the leaf blade. In the middle of the leaf blade is the midrib, which is an extension of the petiole.
Answer:
C- it helps develop scientific consensus by making sure new ideas are critically evaluated.
Answer:
A. It allows two populations to evolve separately.
Explanation:
Geographic isolation is theorized to have catalyzed the formation of new species. Let’s say groups A and B of a bird species get separated by something, and they can’t cross between to interbreed or exchange alleles.
We describe this as no gene flow, which is the opposite of choices C and D. Because of this, they may diverge if given enough time due to the difference in environmental pressures, because they’re now in different environments.
B is incorrect because it doesn’t apply.