The answer that makes the most sense is number one or two. Number 3 and number four both makes no sense in that context. Most of the time an animal will not die or mutate due to a parasite in its body.
Genotype or Phenotype relationships
The correct answer is random fertilization.
Together with crossing over and independent assortment, random fertilization represents the way by which sexually reproduction contributes to genetic variation. <span>Random fertilization refers to the random event of fertilization when there is no way in knowing which sperm will fertilise which egg (64 trillion possible combinations of genes that can occur during fertilization). Any sperm cell from the male can fuse with any egg cell from the female.</span>
