Question

1. why do rotifers reproduce primarily through parthenogenesis?

male rotifers are extremely rare.
female rotifers are extremely rare.
male rotifers are overabundant.
female rotifers are unable to reproduce sexually.

Explanation:

Parthenogenesis is a form of asexual reproduction. For rotifers, male rotifers are extremely rare in many rotifer species, so they primarily reproduce via parthenogenesis. The option "Female rotifers are extremely rare" is incorrect as females are the ones reproducing. "Male rotifers are overabundant" contradicts the rarity of males. "Female rotifers are unable to reproduce sexually" is also incorrect as parthenogenesis is used due to male rarity, not female inability to reproduce sexually.

Answer:

A. Male rotifers are extremely rare.