AP BIOLOGY

Detailed explanation-1: -A normal human cell has 23 pairs chromosomes. So, a total of 46 chromosomes. At the bivalent stage, each chromosome has two chromatids. So a total of 92 chromatids.

Detailed explanation-2: -In human cells, for example, there will be 46 chromosomes in a cell after the S phase. The chromatid number is 92, with each chromosome having two chromatids.

Detailed explanation-3: -Prophase: During prophase, the nuclear envelope of the cell (which is where the 92 sister chromatids are contained) begins to break down. The centrioles, which are only present in animal cells, separate and each moves to an opposite end of the cell.

Detailed explanation-4: -The prophase and metaphase of mitosis have 92 chromatids. At anaphase each chromatid is considered a single chromosome thus at the end of telophase, 92 chromosomes are present (double of 46 chromosomes of parent cell).

Detailed explanation-5: -Each chromosome thus consists of two sister chromatids. At the beginning of meiosis I, a human cell contains 46 chromosomes, or 92 chromatids (the same number as during mitosis).