AP BIOLOGY

CELL DIVISION

MEIOSIS

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
A sex cell from an organism contains 31 chromosomes.How many chromosomes would this cell have contained at the start of meiosis?
A
62
B
94
C
124
D
248
Explanation: 

Detailed explanation-1: -Each daughter cell will have half of the original 46 chromosomes, or 23 chromosomes. Each chromosome consists of 2 sister chromatids. The daughter cells now move in to the third and final phase of meiosis: meiosis II.

Detailed explanation-2: -At the beginning of meiosis I, a human cell contains 46 chromosomes, or 92 chromatids (the same number as during mitosis). Meiosis I proceeds through the following phases: Prophase I: Prophase I is similar in some ways to prophase in mitosis. The chromatids shorten and thicken and become visible under a microscope.

Detailed explanation-3: -Each daughter cell will have 30 chromosomes. At the end of meiosis II, each cell (i.e., gamete) would have half the original number of chromosomes, that is, 15 chromosomes.

Detailed explanation-4: -Egg and sperm cells have just 23 chromosomes each. That’s half as many chromosomes as regular cells. Through the process of fertilization, egg and sperm join to make a cell with 46 chromosomes (23 pairs), called a zygote. For each chromosome pair, one homologous chromosome came from each parent.

There is 1 question to complete.