Genetic variation in a population of animals or plants depends mainly on which of the following?
a) the organism being haploidb) sexual recombinationc) migration of genes among the chromosomesd) mutation

The correct answer is: B) sexual recombination

Sources of genetic variation are different:

•Genetic mutations-random and rare events that occur within the genome and contribute to variations among individuals (or population). Mutations might be neutral, harmful or beneficial when they form new alleles favored by natural selection.

•Crossing over (genetic recombination)-event that occur during the meiosis (cell division that creates gamets)

•Random segregation during meiosis

•Random fertilization

•External source such as transposable genetic elements or retroviruses.

thrombocytopenia, which is a deficiency in blood platelets, can cause bleeding and bruising in the dermis similar to senile purpura. other possible causes include: exposure to ultraviolet rays and aging skin are common causes of senile purpura. senile purpura may also be a sign of collagen loss in the skin and bones.