A normal human cell with 46 chromosomes undergoes meiosis. One tetrad fails to separate during anaphase I. The two pairs of chromosomes separate during anaphase II. Predict the number of chromosomes in each of the four sperm cells produced.(1 point)

Question

Responses

Two sperm cells will each have 23 chromosomes. The other two sperm cells will each have 24 chromosomes.
Two sperm cells will each have 23 chromosomes. The other two sperm cells will each have 24 chromosomes.

Two sperm cells will each have 22 chromosomes. The other two sperm cells will each have 24 chromosomes.
Two sperm cells will each have 22 chromosomes. The other two sperm cells will each have 24 chromosomes.

One sperm cell has 25 chromosomes. Once sperm cell has 21 chromosomes. Two sperm cells each have 22 chromosomes.
One sperm cell has 25 chromosomes. Once sperm cell has 21 chromosomes. Two sperm cells each have 22 chromosomes.

One sperm cell has 26 chromosomes. One sperm cell has 20 chromosomes. Two sperm cells each have 22 chromosomes.

Answer 1

To analyze this meiosis scenario, let's break down the process step by step:

1. Normal Human Cell: A normal human cell has 46 chromosomes (23 pairs).

2. Meiosis: During meiosis, homologous chromosomes pair up and then separate. In this case, during anaphase I, one tetrad fails to separate, meaning one pair of homologous chromosomes remains together.

3. Anaphase I: Normally, in anaphase I, the 23 tetrads (or pairs) would separate into two cells, resulting in two cells with 23 chromosomes each. Since one tetrad did not separate, the cells will not divide equally:

   • One daughter cell will receive both chromosomes from that tetrad, resulting in 24 chromosomes (23 from other pairs + 1 pair that didn't separate).
   • The other daughter cell will have 22 chromosomes (23 from other pairs - 1).

4. Meiosis II: In meiosis II, each of the two cells will undergo division again.

   • The cell with 24 chromosomes will lead to two sperm cells, one with 24 chromosomes and one with 24 chromosomes.
   • The cell with 22 chromosomes will lead to two sperm cells, one with 22 chromosomes and one with 22 chromosomes.

Thus, the resulting chromosomes in the four sperm cells:

• Two sperm cells with 24 chromosomes each
• Two sperm cells with 22 chromosomes each

So the prediction is: Two sperm cells will each have 22 chromosomes. The other two sperm cells will each have 24 chromosomes.