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21) In a life cycle such as that shown in part III of Figure 13.1, if the zygote's chromosome number is 10, which of the following will be true? A) The sporophyte's chromosome number per cell is 10 and the gametophyte's is 5. B) The sporophyte's chromosome number per cell is 5 and the gametophyte's is 10. C) The sporophyte and gametophyte each have 10 chromosomes per cell. D) The sporophyte and gametophyte each have 5 chromosomes per cell. E) The sporophyte and gametophyte each have 20 chromosomes per cell.

Answer: A

28) When does the synaptonemal complex disappear? A) Late prophase of meiosis I B) During fertilization or fusion of gametes C) Early anaphase of meiosis I D) Mid-prophase of meiosis II E) Late metaphase of meiosis II

Answer: A

16) Which of the following is an example of alternation of generations? A) A grandparent and grandchild each has dark hair, but the parent has blond hair. B) A diploid plant (sporophyte) produces, by meiosis, a spore that gives rise to a multicellular, haploid pollen grain (gametophyte). C) A diploid animal produces gametes by meiosis, and the gametes undergo fertilization to produce a diploid zygote. D) A haploid mushroom produces gametes by mitosis, and the gametes undergo fertilization, which is immediately followed by meiosis. E) A diploid cell divides by mitosis to produce two diploid daughter cells, which then fuse to produce a tetraploid cell.

Answer: B

20) In part III of Figure 13.1, the progression of events corresponds to which of the following series? A) Zygote, mitosis, gametophyte, mitosis, fertilization, zygote, mitosis B) Sporophyte, meiosis, spore, mitosis, gametophyte, mitosis, gametes, fertilization C) Fertilization, mitosis, multicellular haploid, mitosis, spores, sporophyte D) Gametophyte, meiosis, zygote, spores, sporophyte, zygote E) Meiosis, fertilization, zygote, mitosis, adult, meiosis

Answer: B

24) A triploid cell contains three sets of chromosomes. If a cell of a usually diploid species with 42 chromosomes per cell is triploid, this cell would be expected to have which of the following? A) 63 chromosomes in 31 1/2 pairs B) 63 chromosomes in 21 sets of 3 C) 63 chromosomes, each with three chromatids D) 21 chromosome pairs and 21 unique chromosomes

Answer: B

25) A karyotype results from which of the following? A) A natural cellular arrangement of chromosomes in the nucleus B) An inherited ability of chromosomes to arrange themselves C) The ordering of human chromosome images D) The cutting and pasting of parts of chromosomes to form the standard array E) The separation of homologous chromosomes at metaphase I of meiosis

Answer: C

26) After telophase I of meiosis, the chromosomal makeup of each daughter cell is A) diploid, and the chromosomes are each composed of a single chromatid. B) diploid, and the chromosomes are each composed of two chromatids. C) haploid, and the chromosomes are each composed of a single chromatid. D) haploid, and the chromosomes are each composed of two chromatids. E) tetraploid, and the chromosomes are each composed of two chromatids.

Answer: D

27) How do cells at the completion of meiosis compare with cells that have replicated their DNA and are just about to begin meiosis? A) They have twice the amount of cytoplasm and half the amount of DNA. B) They have half the number of chromosomes and half the amount of DNA. C) They have the same number of chromosomes and half the amount of DNA. D) They have half the number of chromosomes and one-fourth the amount of DNA. E) They have half the amount of cytoplasm and twice the amount of DNA.

Answer: D

22) The karyotype of one species of primate has 48 chromosomes. In a particular female, cell division goes awry and she produces one of her eggs with an extra chromosome (25). The most probable source of this error would be a mistake in which of the following? A) Mitosis in her ovary B) Metaphase I of one meiotic event C) Telophase II of one meiotic event D) Telophase I of one meiotic event E) Either anaphase I or II

Answer: E

23) A given organism has 46 chromosomes in its karyotype. We can therefore conclude which of the following? A) It must be human. B) It must be a primate. C) It must be an animal. D) It must be sexually reproducing. E) Its gametes must have 23 chromosomes.

Answer: E