Cell Division: Mitosis and Meiosis Flashcards

Which event occurs during meiosis I that distinguishes it from mitosis?

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.

During which specific phase of meiosis does crossing over between homologous chromosomes occur?

Answer: Prophase I

Crossing over occurs during Prophase I when homologous chromosomes are tightly paired as tetrads (bivalents) at the synaptonemal complex.

Which statement correctly distinguishes a diploid (2n) cell from a haploid (n) cell?

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.

During anaphase of mitosis, what separates and moves toward opposite poles of the cell?

Answer: Sister chromatids

During mitotic anaphase, centromeres split and sister chromatids separate, pulled to opposite poles by shortening spindle fibers.

The spindle apparatus is primarily composed of which cellular structure?

Answer: Microtubules (tubulin)

Spindle fibers are composed of microtubules — polymers of tubulin protein — that attach to chromosomes at the kinetochore and pull them apart.

A somatic cell containing 46 chromosomes undergoes mitosis. How many chromosomes will each daughter cell contain?

Answer: 46

Mitosis maintains chromosome number; each daughter cell receives a complete, identical set of 46 chromosomes as the parent cell.

Which phase of meiosis most closely resembles mitosis because sister chromatids (not homologs) separate?

Answer: Meiosis II

Meiosis II resembles mitosis in that sister chromatids separate (rather than homologs), though the cells entering meiosis II are already haploid.