Mitosis and meiosis are both cellular processes used for reproduction. Mitosis i
ID: 67252 • Letter: M
Question
Mitosis and meiosis are both cellular processes used for reproduction. Mitosis is cellular reproduction, in which two identical daughter cells are produced. Meiosis, on the other hand, is important for gamete formation and is therefore required for organisms to reproduce sexually.
1. If a diploid organism has 96 chromosomes in a somatic cell, how many chromosomes will be present in each daughter cell at the end of mitosis? How many chromosomes will be present in each daughter cell at the end of meiosis?
2. Patau syndrome is a rare disease that results from having an extra chromosome 13 in all cells. Most infants with this disease die within the first few weeks of life, as severe defects in many organ systems result. A defect in the formation of chiasma during meiosis I could lead to the production of egg cells with two copies of chromosome 13.Explain why this is and describe how many copies of chromosome 13 each of the 4 meiotic products will have in this situation at the end of meiosis II.
Explanation / Answer
1). Given that, the number of chromosomes in a diploid organism is = 96. Means, 2N = 96.
At the end of mitosis, each daughter cell contains 2N number of chromosomes similar to the mother cell. Thus, the number of chromosomes present in each daughter cell at the end of mitosis is 96.
As meiosis is reduction division, number of chromosomes present at the end of meiosis is reduced to half and the daughter cells contain N number of chromosomes (half to that of their mother cells). Thus, the number of chromosomes present in each daughter cell at the end of meiosis is 48.