AP BIOLOGY

Detailed explanation-1: -For example, prior to undergoing meiosis, a cell goes through an interphase period in which it grows, replicates its chromosomes, and checks all of its systems to ensure that it is ready to divide. Like mitosis, meiosis also has distinct stages called prophase, metaphase, anaphase, and telophase.

Detailed explanation-2: -DNA must be packaged into chromosomes prior to mitosis or meiosis to ensure the equal distribution of DNA into the daughter cells.

Detailed explanation-3: -Cells must replicate their DNA before they can divide. This ensures that each daughter cell gets a copy of the genome, and therefore, successful inheritance of genetic traits.

Detailed explanation-4: -Before meiosis begins, the DNA in each chromosome is replicated. The two identical copies that result from this DNA replication are referred to as ‘sister chromatids’, and are joined to each other by a region of the chromosome called the centromere (as shown in figure 1).

Detailed explanation-5: -Before mitosis, the chromosomes are copied. They then coil up, and each chromosome looks like a letter X in the nucleus of the cell. The chromosomes now consist of two sister chromatids. Mitosis separates these chromatids, so that each new cell has a copy of every chromosome.