During which specific stage of cell division does genetic recombination via crossing over between non-sister chromatids take place?
Answer and explanation
Correct answer: B. Prophase I of meiosis
- Step 1: Recall stages of meiosis: during prophase I, homologous chromosome pairs align side by side in synapsis to form tetrads.
- Step 2: Non-sister chromatids intertwine at chiasmata and exchange reciprocal homologous DNA segments (crossing over), creating recombinant chromatids.
Answer
Prophase I of meiosis.
Why not the others: 'Metaphase II of meiosis' involves individual chromosomes aligning along the equatorial plate; 'Prophase of mitosis' condenses chromatin without pairing of homologues or crossing over; 'Anaphase I of meiosis' separates homologous chromosome pairs towards opposite poles.
Practise more Safety, Body Coordination, Nervous and Endocrine Systems, and Genetics.
Free questions with an explanation for every one, and full timed SPM Malaysia mock tests.
More Safety, Body Coordination, Nervous and Endocrine Systems, and Genetics questions
- Which type of fire extinguisher is specifically designated for extinguishing fires involving live electrical equipment in a laboratory?
- What is the correct immediate safety protocol when liquid mercury is spilled from a broken laboratory thermometer?
- Which anatomical components constitute the human central nervous system (CNS)?
- What is the correct pathway of a nerve impulse during a spinal reflex arc, such as withdrawing a hand from a sharp object?
- Which region of the human brain is primarily responsible for coordinating muscular contractions, maintaining bodily balance, and regulating…
- Which vital involuntary physiological activities are directly controlled by the medulla oblongata?