SAT Cell Division: Mitosis and Meiosis 2 — Questions and Answers
Question 1: Which event occurs during meiosis I that distinguishes it from mitosis?
- DNA replication
- Separation of homologous chromosome pairs (Correct answer)
- Separation of sister chromatids
- Cytokinesis
Correct answer: Separation of homologous chromosome pairs
During meiosis I, homologous chromosome pairs (bivalents) separate from each other, a process unique to meiosis that does not occur in mitosis.
Question 2: During which specific phase of meiosis does crossing over between homologous chromosomes occur?
- Prophase II
- Anaphase I
- Prophase I (Correct answer)
- Metaphase I
Correct answer: Prophase I
Crossing over occurs during Prophase I when homologous chromosomes are tightly paired as tetrads (bivalents) at the synaptonemal complex.
Question 3: Which statement correctly distinguishes a diploid (2n) cell from a haploid (n) cell?
- Diploid cells have half the DNA of haploid cells
- Haploid cells contain two copies of each chromosome
- Diploid cells contain two complete sets of homologous chromosomes (Correct answer)
- Haploid cells are produced only by mitosis
Correct answer: Diploid cells contain two complete sets of homologous chromosomes
Diploid cells contain two homologous sets of chromosomes (one maternal, one paternal), while haploid cells contain only one set.
Question 4: During anaphase of mitosis, what separates and moves toward opposite poles of the cell?
- Homologous chromosomes
- Tetrads
- Sister chromatids (Correct answer)
- Nucleoli
Correct answer: Sister chromatids
During mitotic anaphase, centromeres split and sister chromatids separate, pulled to opposite poles by shortening spindle fibers.
Question 5: The spindle apparatus is primarily composed of which cellular structure?
- Microfilaments (actin)
- Intermediate filaments
- Microtubules (tubulin) (Correct answer)
- Centrioles
Correct answer: Microtubules (tubulin)
Spindle fibers are composed of microtubules — polymers of tubulin protein — that attach to chromosomes at the kinetochore and pull them apart.
Question 6: A somatic cell containing 46 chromosomes undergoes mitosis. How many chromosomes will each daughter cell contain?
- 23
- 46 (Correct answer)
- 92
- 46, derived from 92 during anaphase
Correct answer: 46
Mitosis maintains chromosome number; each daughter cell receives a complete, identical set of 46 chromosomes as the parent cell.
Question 7: Which phase of meiosis most closely resembles mitosis because sister chromatids (not homologs) separate?
- Meiosis I
- Prophase I
- Meiosis II (Correct answer)
- Interkinesis
Correct answer: Meiosis II
Meiosis II resembles mitosis in that sister chromatids separate (rather than homologs), though the cells entering meiosis II are already haploid.
SAT Cell Division: Mitosis and Meiosis 2
Which event occurs during meiosis I that distinguishes it from mitosis?