Meiosis I — NEET Biology MCQs with Solutions
Free NEET Biology Meiosis I MCQs with step-by-step solutions (6 questions). Part of Cell Cycle and Cell Division. Practise online on Prepizo — no login needed.
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Questions with solutions
Q1 — Meiosis I · easy · theory
Pairing of homologous chromosomes (synapsis) to form bivalents occurs during:
A. Prophase II
B. Prophase I (zygotene) ✓ Correct
C. Anaphase I
D. Metaphase I
Solution: Homologous chromosomes pair (synapsis) during zygotene of prophase I, forming bivalents/tetrads.
Q2 — Meiosis I · easy · theory
Crossing over — exchange of segments between non-sister chromatids — takes place during the ______ substage of prophase I:
A. Diplotene
B. Pachytene ✓ Correct
C. Leptotene
D. Diakinesis
Solution: Crossing over (recombination) occurs at pachytene, mediated by the recombination nodules on the synaptonemal complex.
Q3 — Meiosis I · medium · theory
The X-shaped points where crossing over has occurred, visible during diplotene, are called:
A. Bivalents
B. Chiasmata ✓ Correct
C. Kinetochores
D. Centromeres
Solution: Chiasmata are the sites of crossover, holding homologues together until anaphase I.
Q4 — Meiosis I · medium · theory
The reduction in chromosome number from diploid to haploid occurs in meiosis I because:
A. Sister chromatids separate
B. Cells fuse
C. DNA replicates again
D. Homologous chromosomes (not sister chromatids) separate ✓ Correct
Solution: Anaphase I separates homologous chromosomes to opposite poles — hence meiosis I is the reductional division.
Q5 — Meiosis I · hard · theory
The correct sequence of prophase I substages is:
A. Pachytene → Diplotene → Zygotene
B. Leptotene → Zygotene → Pachytene → Diplotene → Diakinesis ✓ Correct
C. Zygotene → Leptotene → Pachytene
D. Diakinesis → Leptotene → Zygotene
Solution: Prophase I: leptotene (condensation) → zygotene (synapsis) → pachytene (crossing over) → diplotene (chiasmata) → diakinesis (terminalisation).
Q6 — Meiosis I · hard · theory
In a cell with 2n = 8, the number of bivalents (tetrads) formed during metaphase I is:
A. 4 ✓ Correct
B. 16
C. 2
D. 8
Solution: Homologues pair up, so the number of bivalents = n = 4 (each bivalent has 2 homologues, 4 chromatids).