Genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).
T cells. When HIV arrives in the lymph nodes – around 24 to 48 hours after exposure – they activate other immune cells, such as CD4 t-cells, HIV's primary target.
Answer:
Option C. A person inherits chromosomes from just one parent.
Explanation:
Genetic disorders or diseases that are caused by errors that occur during meiosis is called down syndrome. It is also known as trisomy 21. In this disease the person inherits one extra pair of chromosomes from one of the parent i. e. Father or mother.
