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OperonBiology
Select all that applyDifficulty 3/5 · ChallengingOlympiadConcept explanationVisual representation

Two errors, two outcomes

Topic: Chromosomal inheritance & nondisjunction

A cytogeneticist studies two primary spermatocytes from the same man (2n = 46). In spermatocyte 1, the two homologous chromosomes 21 fail to separate in meiosis I; meiosis II is normal. In spermatocyte 2, meiosis I is normal, but in one of the two secondary spermatocytes the sister chromatids of chromosome 21 fail to separate in meiosis II. Each spermatocyte gives four sperm.

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