AP BIOLOGY

CELL DIVISION

MEIOSIS

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
At fertilization the male and female sex cells will provide ____
A
Double of their chromosomes each
B
One/third of their chromosomes each
C
All of their chromosomes each
D
Half of their chromosomes each
Explanation: 

Detailed explanation-1: -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.

Detailed explanation-2: -Gametes are reproductive cells, such as sperm and egg. As gametes are produced, the number of chromosomes must be reduced by half. Why? The zygote must contain genetic information from the mother and from the father, so the gametes must contain half of the chromosomes found in normal body cells.

Detailed explanation-3: -During fertilization, male and female gametes fuse, producing a diploid (i.e., containing paired chromosomes) zygote.

Detailed explanation-4: -When the sperm and egg cells unite at conception, each contributes 23 chromosomes so the resulting embryo will have the usual 46. Meiosis also allows genetic variation through a process of gene shuffling while the cells are dividing.

Detailed explanation-5: -In the human reproductive process, two kinds of sex cells, or gametes (GAH-meetz), are involved. The male gamete, or sperm, and the female gamete, the egg or ovum, meet in the female’s reproductive system. When sperm fertilizes (meets) an egg, this fertilized egg is called a zygote (ZYE-goat).

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