AP BIOLOGY

Detailed explanation-1: -Cancer is a disease in which cells divide slowly. If chromosomes do not separate correctly during the formation of sex cells, the organism that forms can end up with too many or too few chromosomes. Cancer causes the growth of tumors. Scientists think that cancer begins when something damages a cells protiens.

Detailed explanation-2: -If the chromosomes don’t split into equal halves, the new cells can have an extra chromosome (47 total) or have a missing chromosome (45 total).

Detailed explanation-3: -In nondisjunction, the separation fails to occur causing both sister chromatids or homologous chromosomes to be pulled to one pole of the cell.

Detailed explanation-4: -Nondisjunction is the result of failure of chromosomes to separate during mitosis. This leads to new cells with either extra or missing chromosomes; a condition called aneuploidy. Human embryos with aneuploidy rarely survive development; with only 0.3 percent of human aneuploidy pregnancies producing a live birth.