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Question 73

A human body cell contains 23 pairs of chromosomes. How do the sex chromosomes fit into that count?

  1. They are one of the 23 pairsBonne réponse
  2. All 23 pairs are sex chromosomes
  3. They are two extra chromosomes held outside the 23 pairs
  4. They are found only in reproductive organs and not in ordinary body cells

Explication

A body cell holds 46 chromosomes in total, and that total already includes the two sex chromosomes, so they are counted inside the 23 pairs, not alongside them. Holding them outside the pairs would give a body cell 48 chromosomes, and a set made up entirely of sex chromosomes would leave no room for the genes the remaining pairs carry.

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Question 73: A human body cell contains 23 pairs of chromosomes. How do… · Genetics Basics · Questena