Practice 1, Chapter 2

How many first polar bodies would be formed?

180

How many ootids would be formed?

180

If one follows 180 primary oocytes in an animal through their various stages of oogenesis, how many secondary oocytes would be formed?

180

If one follows 180 primary spermatocytes in an animal through their various stages of spermatogenesis, how many secondary spermatocytes would be formed?

380

How many chromosomes are present in the second polar body?

5

How many chromosomes are present in the mature ovum?

7

How many spermatids would be formed?

720

After meiosis I, assuming no crossing over, what combinations of chromosomes are possible in the two product cells? Select all that apply. A) Am, Bm, Cp B) Ap, Bm, Cm C) Am, Bp, Cp D) Ap, Bp, Cm E) Am, Bp, Cm F) Ap, Bp, Cp G) Ap, Bm, Cp H)Am, Bm, Cm

A) Am, Bm, Cp B) Ap, Bm, Cm C) Am, Bp, Cp D) Ap, Bp, Cm E) Am, Bp, Cm F) Ap, Bp, Cp G) Ap, Bm, Cp H)Am, Bm, Cm

During which stage of prophase I does crossing over take place? A) Pachynema B) Diplonema C) Diakinesis D) Leptonema

A) Pachynema Crossing over occurs during pachynema when bivalents are closely paired.

What would most likely be true of these two chromosomes? Select all that apply. A) They are homologous chromosomes. B) They have similar banding patterns. C) They would replicate synchronously during the S phase of the cell cycle. D) They contain identical genetic information.

A) They are homologous chromosomes. B) They have similar banding patterns. C) They would replicate synchronously

A tetrad is composed of one pair of homologous chromosomes at synapsis of prophase I. A) True D) False

A) True Chromosomes are duplicated during interphase; at synapsis of prophase I, one chromosome (with two chromatids) in a tetrad is paternally inherited while the other is maternally inherited.

Each of the following events occurs during mitosis except _______. A) polar microtubules contract, pulling attached chromosomes toward the poles B) chromosomes condense C) microtubules assemble between centrioles D) nuclear membrane breaks down

A) polar microtubules contract, pulling attached chromosomes toward the poles This describes the role of kinetochore microtubules during anaphase. Polar microtubules lengthen during anaphase, causing the cell to become elliptical.

Which list of steps in the eukaryotic cell cycle is given in the correct order? (step order listed left to right) A) . . . G1 - G2 - S - M - G1 . . . B) . . . G1 - S - G2 - M - G1 . . . C) G1 - S - G2 - M1 - M2 - G1 . . . D) . . . G1 - M - G2 - S - G1 . . .

B) . . . G1 - S - G2 - M - G1 . . . The S phase is both preceded and followed by a period of growth (G1 and G2, respectively). After the M phase, the cell re-enters the G1 phase.

Haploid cells do not undergo mitosis. A) True B) False

B) False Both haploid and diploid cells can undergo mitosis.

When do sister chromatids separate during meiosis? A) Anaphase I B) Metaphase II C) Anaphase II D) Metaphase I

C) Anaphase II Sister chromatids from each dyad separate during anaphase II.

Following fertilization by a normal sperm, what chromosome condition is created? A) monosomy B) disomy C) trisomy D) polyploidy

C) trisomy