In the testes of a healthy man there are diploid cells that undergo meiosis to produce gametes.
Which of the following statements is/are correct about meiosis for one of these diploid cells?
A. 3 only
B. 2 and 3 only
C. 1, 2 and 3
D. 1 and 3 only
E. 1 only
The correct answer is D.
What is meiosis?
It is a type of cell division, just like mitosis.
Its purpose is to reduce the number of chromosomes in gametes and, ultimately, to allow sexual reproduction.
Indeed, since we humans have 46 chromosomes (2n = 46), it is not possible for the child to receive 46 chromosomes from both parents.
Furthermore , each diploid cell undergoes 2 rounds of division, and ultimately, yields 4 haploid cells. To make this possible, just before the cell enters meiosis, it duplicates its DNA and therefore, item 1 is correct.
In addition, we know that 1 mother cell yields 4 haploid cells, which means that the total number of chromosomes produced by the end of meiosis II is double that of the original diploid cell. This makes item 3 correct.
The daughter cells are obtained after going through the 4 different phases and 2 different cell divisions :
Therefore, meiosis ends with meiosis II.
We know that the daughter cells at the end of the division are haploid, which makes item 2 incorrect.
A diploid cell has 2 complete sets of chromosomes (2n) and a haploid cell only has 1 set of chromosomes (n)
I cannot understand why 2 is incorrect. The cells are diploid at the start of meiosis II, until the anaphase II. So number 2 is correct, too.
I struggle with this part too… did you find an answer that satisfied you? and if you did could you please share?
Yeah sure. 2 is incorrect cuz when a cell has 2 versions of each chromosome, we call it a diploid cell. But in anaphase 1, half of the chromosomes go to one cell and another half go to another new cell. So, each new cell has just 1 version of each chromosome.
I hope I explained it understandable to you:sweat_smile: