Question
Germ cells are specialized cells that develop into gametes. Gametes are produced through the process of meiosis. If the diploid number for humans is 46 chromosomes, how many chromatids does a cell underg meiosis have at each of the following phases? Select the row that correctly shows the number of chromatids at each phase. a. G2 of Interphase & Metaphase I & Prophase II 46 & 92 & 23 b. G2 of Interphase & Metaphase I & Prophase II 92 & 92 & 46 c. G2 of Interphase & Metaphase I & Prophase II 92 & 46 & 46 d. G2 of Interphase & Metaphase I & Prophase II 46 & 46 & 23
Solution
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RenataMaster · Tutor for 5 years
Answer
B.
Explain
## Step 1:
To answer this question, we need to understand the concept of meiosis and the different phases involved in a meiosis process. Germ cells, being precursors to gametes, undergo meiosis. In humans, the diploid number (2n) of chromosomes is 46, which means that germ cells in humans contain 46 chromosomes.
## Step 2:
On the row "G2 of Interphase", a cell gets prepared for meiosis. During the phase itself, the number of chromosomes remains at 46, but each chromosome has been duplicated leading to two sister chromatids. Thus, there are twice as many chromatids as chromosomes.
### The number of chromatids at "G2 of Interphase" is .
## Step 3:
On the row "Metaphase I", once the meiosis I takes place, we end up with two cells having splitted up the sister chromatids while keeping the homologous pairs together. Each of these chromosomes represents one homolog which already consists of two tightly joined sister chromatids. Hence, the number of chromatids remains unchanged.
### The number of chromatids at "Metaphase I" is also .
## Step 4:
Finally, on the row "Prophase II", moving towards the preparation of cell for meiosis II which involves separating the sister chromatids. So, the counting is different, we count separated chromosomes' number.
### The number of chromatids at "Prophase II" is .
Collectively, the number of chromatids at each specific phase corresponds to option b.
To answer this question, we need to understand the concept of meiosis and the different phases involved in a meiosis process. Germ cells, being precursors to gametes, undergo meiosis. In humans, the diploid number (2n) of chromosomes is 46, which means that germ cells in humans contain 46 chromosomes.
## Step 2:
On the row "G2 of Interphase", a cell gets prepared for meiosis. During the phase itself, the number of chromosomes remains at 46, but each chromosome has been duplicated leading to two sister chromatids. Thus, there are twice as many chromatids as chromosomes.
### The number of chromatids at "G2 of Interphase" is .
## Step 3:
On the row "Metaphase I", once the meiosis I takes place, we end up with two cells having splitted up the sister chromatids while keeping the homologous pairs together. Each of these chromosomes represents one homolog which already consists of two tightly joined sister chromatids. Hence, the number of chromatids remains unchanged.
### The number of chromatids at "Metaphase I" is also .
## Step 4:
Finally, on the row "Prophase II", moving towards the preparation of cell for meiosis II which involves separating the sister chromatids. So, the counting is different, we count separated chromosomes' number.
### The number of chromatids at "Prophase II" is .
Collectively, the number of chromatids at each specific phase corresponds to option b.
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