EMBRYOLOGY
CHROMOSOMES AND CELL DIVISIONS
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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because they are made of 2 sister chromatins
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because they are made of 2 sister centromeres
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because they are made of 2 sister chromosomes
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because the are made of 2 sister chromatids
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Detailed explanation-1: -During mitosis, DNA condenses to form visible chromosomes, and these two identical copies, or sister chromatids, are attached to each other and form an ‘X’ shape. While sister chromatids are exact copies of each other, non-sister chromatids come from homologous chromosomes.
Detailed explanation-2: -DNA condenses and coils into the familiar X-shaped form of a chromosome only after it has replicated. Because DNA has already replicated, each chromosome actually consists of two identical copies. The two copies are called sister chromatids.
Detailed explanation-3: -Sister chromatids are by and large identical (since they carry the same alleles, also called variants or versions, of genes) because they derive from one original chromosome.