Which of these sentences describe sources and preservation of genetic variation? Select all that apply.

A. Antibiotic resistance in bacterial populations is caused by natural selection of bacteria that inherit mutations that make them resistant to the antibiotics.

B. If a cell has two pairs of chromosomes, four kinds of gametes are possible as a result of reshuffling of chromosomes during meiosis.

C. Crossing-over causes a shuffling of allele combinations during meiosis as the alleles from each parent form new combinations on homologous chromosomes.

D. During mitosis in eukaryotes, the sister chromatids are separated and distributed to two daughter cells.

E. When two bacteria are linked during conjugation, the donor cell passes DNA to the recipient cell which causes genetic recombination.

Genetic variation can be defined as the difference in the DNA sequences between the individuals in the population

Explanation:

Antibiotic resistance in bacterial populations is caused by natural selection of bacteria that inherit mutations that make them resistant to the antibiotics, this sentence describes the source and preservation of genetic variation. The Mutation is one of the genetic variation or disorder, and probably bacteria choose mutation to become repellent to antibiotics In some of the cases of spontaneous bacteria have been obtained from other sets of bacteria through the process and make the bacteria repellent to an antibiotic. They survive antibiotic treatment and increase in numbers by natural selection. Natural selection can be stated as the process in which organism survive and reproduce adapting to the environment