Best description of the process of crossing over during meiosis:
Correct answer: B. Exchange of genes between non-sister chromatids
- A. Duplication of chromosome
- B. Exchange of genes between non-sister chromatids
- C. Movement of chromosome to opposite poles
- D. Separation of sister chromatids
Explanation
During prophase I the homologues pair as bivalents and non sister chromatids exchange equal segments at chiasmata, producing chromosomes carrying combinations neither parent had. The exchange must be between non sister chromatids, since sister chromatids are identical and swapping between them would change nothing. Separation of sister chromatids happens later, in anaphase II.
This question appeared on the UHS MDCAT 2025 paper, which you can sit online with every answer explained.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? support@testustad.com
About Gene Linkage and Crossing Over
Linked genes lie on the same chromosome and tend to pass together, unlike genes that assort independently on different chromosomes. The topic connects linkage with homologous pairing, crossing over during prophase I of meiosis, recombinant and parental offspring, and recombination frequency as an estimate of gene distance.
Practise Inheritance
1,238 free Inheritance MCQs from Biology, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Biology questions like this
Biology is on 8 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.