AP BIOLOGY

Detailed explanation-1: -During mitosis, a cell duplicates all of its contents, including its chromosomes, and splits to form two identical daughter cells. Because this process is so critical, the steps of mitosis are carefully controlled by certain genes.

Detailed explanation-2: -Since the cell is dividing it needs two copies of its DNA-one is kept by the parent cell and the other is passed to the daughter cell. If cells don’t replicate their DNA or don’t do it completely, the daughter cell will end up with no DNA or only part of the DNA. This cell will likely die.

Detailed explanation-3: -Prophase. Figure 1: During prophase, the chromosomes in a cell’s nucleus condense to the point that they can be viewed using a light microscope. Prophase is the first phase of mitosis. During this phase, the chromosomes inside the cell’s nucleus condense and form tight structures.

Detailed explanation-4: -There are two divisions in meiosis; the first division is meiosis I: the number of cells is doubled but the number of chromosomes is not. This results in 1/2 as many chromosomes per cell. The second division is meiosis II: this division is like mitosis; the number of chromosomes does not get reduced.

Detailed explanation-5: -When one cell divides into two, both must have a copy of the genetic information. Therefore, before cell division occurs, the genes must also make duplicates of themselves so that all of the important genetic information ends up in each of the new cells.