Record a major difference in spermatogenesis and oogenesis. Remember to compare this difference in the male and female. Please help me

In the context of the neural impulse, which of the following is true about the depolarization of neuron membranes?

Which of the following statements is true about the relationship between genetic variation and natural selection? a. genetic variation must be present in a population before natural selection can act on it. b. genetic variation arises in a population as a result of natural selection. c. natural selection can act on a population whether there is genetic variation within the population or not. d. after natural selection acts on a population, the amount of genetic variation in the population always increases.

The color of the fur is the genotypephenotype.the genetic combination of alleles that determine the fur color is called the genotypephenotype.