AP BIOLOGY

Detailed explanation-1: -In Meiosis I, each daughter cell receives a mix of chromosomes from the two sets in the parent cell. In addition, the chromosomes in each matching pair swap some genetic material before they are parted in a process called crossing over. These processes produce new combinations of genes in the sperm cells and egg cells.

Detailed explanation-2: -Gene Transfer: The introduction of new DNA into an existing organism’s cell, usually by vectors such as plasmids and modified viruses. Cells may be modified ex vivo for subsequent administration to humans, or may be altered in vivo by gene therapy given directly to the subject.

Detailed explanation-3: -Conjugation is the transfer of DNA by direct cell-to-cell contact that is mediated by plasmids (nonchromosomal DNA molecules). Conjugative plasmids encode an extremely efficient mechanism that mediates their own transfer from a donor cell to a recipient cell.

Detailed explanation-4: -One copy is inherited from their mother (via the egg) and the other from their father (via the sperm). A sperm and an egg each contain one set of 23 chromosomes. When the sperm fertilises the egg, two copies of each chromosome are present (and therefore two copies of each gene), and so an embryo forms.