Maybe c or d
Step by step:
The answer is : crossing over can increase genetic variations during meiosis
<em>Examples of a nonspecific external response to infectious agents and harmful bacteria are the following;</em>
Mucus, saliva, and tears.
They are nonspecific external responses that help to prevent pathogens from entering our bodies.
The specifics contain types of enzymes that break down the bacterial cell walls. An external response of Mucus tends to trap pathogens as well.
50% will be heterozygous. 50% will be homozygous. 75% will have the same phenotype as their parents.
