CELL DIVISION
MEIOSIS AND GENETIC VARIATION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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The DNA content of the cell in metaphase I is 0.5X.
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The DNA content of the cell in metaphase I is X.
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The DNA content of the cell in metaphase I is 2X.
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The DNA content of the cell in metaphase I is 4X.
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The DNA content of the cell in metaphase I is 3X.
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Detailed explanation-1: -A diploid cell starts with 2N chromosomes and 2X DNA content. After DNA replication, the cells is still genetically diploid (2N chromosome number), but has 4X DNA content because each chromosome has replicated its DNA. Each chromosome now consists of a joined pair of identical sister chromatids.
Detailed explanation-2: -If the DNA content of a diploid cell is x in the G1 phase of the cell cycle and 2x at metaphase of meiosis |, then the DNA content of the same cell at metaphase of meiosis Il will be 0.25x 21 0.5.
Detailed explanation-3: -If the cell undergoes mitosis, each daughter cell will return to 2c and 2n, because it will receive half of the DNA, and one of each pair of sister chromatids.
Detailed explanation-4: -Thus, the DNA content of the cell will be 2 X at metaphase-1.