Question

1. If humans have 46 chromosomes in each of their body cells, which of the following is NOT true?

a)    Sperm cells have 23 chromosomes b. Egg cells have 23 chromosomes c. Daughter cells from mitosis have 46 chromosomes d. Daughter cells from meiosis II have 46 chromosomes 2. Which of the following is not one of the three important results from meiosis? a. two identical cells produced at teh end b. crossover of homologous chrmosomes c. independent assortment of the chromosomes d. reduction of the chromosomes number from 23 pairs to 23 total 3. What is the result of the crossover even in meiosis? a. A small section of teh chromosome from one parent is switched for the same section of chromosome from the other parent. b. The two homologous chromosomes cross from one side of teh cell during mitosis to the other side c. A male gamete (Sperm) crosses over and becomes a female gamete (egg) d. Two sperm cross over the membrane and fertilize one egg resulting in identical twins

Answer 1

1) Option d is correct.

The statement that Daughter cell have fro meiosis II have 46 chromosomes is not true with regards to humans. Afetr meiosis II, daughter cells have only half the number of chromosomes present in parent cell. The chromosome number is halved in meiosis to maintain the chromosome number in the subsequent generations.

2) Option a is correct.

At the end of Meiosis, 4 identical cells are produced with chromosome number equal to half of the chromosomes present in parent cell. Crossing over and independent assortment are important phenomenon takin place during meiosis and are necessary for recombination of genes.

3) Option a is correct.

In crossing over during meiosis, a small section of the chromosome from one parent is switched for the same section of chromosome from the other parent. This causes recombination of genetic alleles and is responsible for genetic variability between different organisms.