Ch.13

54) Which of the following results when homologous chromosomes cross over in meiosis?

Corresponding segments of non-sister chromatids are exchanged.

40) Which of the following processes occur during meiosis but not mitosis?

Diploid cells form haploid cells.

45) Which of the following statements describes one characteristic of each chromosome in a cell during the entire process of meiosis I?

Each chromosome consists of two sister chromatids joined by a centromere.

7) Which of the following statements is true of a species that has a chromosome number of 2n = 16?

Each diploid cell has eight homologous pairs of chromosomes.

50) A (hypothetical) diploid organism has different genes that control wing color and wing length. A female of this species has a paternal chromosome set containing one orange-wing allele and one long-wing allele and a maternal set containing one blue-wing allele and one short- wing allele. Which of the following types of eggs would she be expected to produce after meiosis?

Each egg has a one-fourth chance of having either blue long, blue short, orange long, or orange short combinations.

23) Which of the following events happens at the conclusion of meiosis I?

Homologous chromosomes of a pair are separated from each other.

30) Cells from a diploid protist with n=1 are followed through mitosis and meiosis. The drawings in the figure below represent the chromosomes. Refer to the drawings and answer the following question(s). Which diagram represents anaphase I of meiosis?

I

36) Multiple cells from the same species were isolated, the relative cohesion protein content for each type was determined, and the results were plotted on the graph. Refer to the graph to answer the following question. Which sample is consistent with a cell that is in telophase I?

I

35) Multiple cells from the same species were isolated, the relative cohesion protein content for each type was determined, and the results were plotted on the graph. Refer to the graph to answer the following question. Which sample is consistent with a cell that is in metaphase I?

II

38) Multiple cells from the same species were isolated, the relative cohesion protein content for each type was determined, and the results were plotted on the graph. Refer to the graph to answer the following question. Which sample is consistent with a cell that is entering mitosis?

II

32) Cells from a diploid protist with n=1 are followed through mitosis and meiosis. The drawings in the figure below represent the chromosomes. Refer to the drawings and answer the following question(s). Which diagram represents prophase of mitosis?

III

34) Multiple cells from the same species were isolated, the relative cohesion protein content for each type was determined, and the results were plotted on the graph. Refer to the graph to answer the following question. Which sample is consistent with a cell that has completed meiosis?

III

37)Multiple cells from the same species were isolated, the relative cohesion protein content for each type was determined, and the results were plotted on the graph. Refer to the graph to answer the following question. Which sample is consistent with a cell that has completed mitosis?

III

48) Which of the following explanations correctly describes a reproductive approach?

In asexual reproduction, a single individual is the sole parent and passes copies of its genes to its offspring without the fusion of gametes.

5) Which of the following statements about reproduction is correct?

In sexual reproduction, individuals transmit half of their nuclear genes to each of their offspring.

56) Which of the following pairs of processes make the greatest contribution to genetic diversity between generations of a diploid insect

Independent assortment and random fertilization

16) Which of the following statements about the human X chromosomes is correct?

It carries genes that influence an individual's biological sex.

19) A cell has completed meiosis I and the first cytokinesis, and is just beginning meiosis II. Which of the following statements describes its genetic contents?

It has half the amount of DNA as the cell that began meiosis.

17) Which of the following statements correctly describes a karyotype?

It is an organized image of a cell's chromosomes.

11) A particular organism has 46 chromosomes in its karyotype. Which of the following statements is correct regarding this organism?

It produces gametes with 23 chromosomes.

42) Which of the following statements describes a major difference between meiosis II and mitosis in a diploid animal?

Meiosis II occurs in a haploid cell, while mitosis occurs in diploid cells.

59) Genetic variation leads to genetic diversity in populations and is the raw material for evolution. Which of the following statements best represents the connection between reproduction and evolution?

Sexual reproduction increases genetic variation because random mutations can be shuffled between organisms.

55) How does natural selection apply to sexual reproduction as opposed to asexual reproduction?

Sexual reproduction results in new gene combinations, some of which will have increased reproductive fitness.

43) Which of the following statements describes a major difference between mitosis and meiosis I in a diploid organism?

Sister chromatids separate in mitosis, while homologous pairs of chromosomes separate in meiosis I.

58) Two different species of protists living in a tide pool. Species A reproduces both sexually and asexually, and Species B reproduce only asexually. The pool gradually becomes infested with disease-causing viruses. Which species are more likely to survive in the changing environment?

Species A only

12) A triploid cell contains three sets of homologous chromosomes. Which of the following describes the chromosomes in a triploid cell where n = 6?

The cell has 18 total chromosomes in 6 sets.

21) Which of the following statements describes the chromosomal makeup of each daughter cell after telophase of meiosis I?

The cells are haploid, and the chromosomes are each composed of two chromatids.

22) How do cells at the completion of meiosis compare with cells that are in prophase of meiosis I?

The cells have half the number of chromosomes and one-fourth the amount of DNA.

20) The somatic cells of a particular plant each contain a total of 46 chromosomes. How do the chromosomes of this plant differ from the chromosomes of humans, who also have a total of 46?

The genes on this plant's largest chromosome are significantly different than those on the largest human chromosome.

14) Which of the following statements best describes homologous chromosomes?

They carry information for the same traits.

31) Cells from a diploid protist with n=1 are followed through mitosis and meiosis. The drawings in the figure below represent the chromosomes. Refer to the drawings and answer the following question(s). Which diagram represents anaphase II of meiosis?

V

33) Cells from a diploid protist with n=1 are followed through mitosis and meiosis. The drawings in the figure below represent the chromosomes. Refer to the drawings and answer the following question(s). Which diagram represents metaphase of mitosis?

VI

28) For the following question, match the key event of meiosis with the stages listed below. I. Prophase I V. Prophase II II. Metaphase I VI. Metaphase II III. Anaphase I VII. Anaphase II IV. Telophase I VIII. Telophase II Cohesins at centromeres of sister chromatids breakdown.

VII

29) For the following question, match the key event of meiosis with the stages listed below. I. Prophase I V. Prophase II II. Metaphase I VI. Metaphase II III. Anaphase I VII. Anaphase II IV. Telophase I VIII. Telophase II Haploid cells form containing joined sister chromatids.

VIII

8) Which of the following characteristics are part of the sexual life cycle of most fungi but are not part of the sexual life cycles of plants or animals?

a unicellular haploid stage

52) For a species with a haploid number of 23 chromosomes, how many different combinations of maternal and paternal chromosomes are possible for the gametes based on the independent assortment of chromosomes during meiosis?

about 8 million

18) Which of the following processes will most likely produce a human zygote with 45 chromosomes?

an error during anaphase II while the sperm was produced

41) During which of the following phases of meiosis do homologous chromosomes separate?

anaphase I

47) During which of the following phases of meiosis do centromeres split and sister chromatids migrate to opposite poles of the cell?

anaphase II

1) If a plant biologist succeeds in generating a single plant with a particularly desirable flower, which of the following approaches would be the most efficient way to generate more plants with this trait?

clone the plant

24) During which of the following processes do sister chromatids separate from each other?

during both mitosis and meiosis II

15) Many diploid organisms produce haploid gametes for reproduction. Which of the following best describes how the diploid number of chromosomes is restored in the offspring of these organisms?

fertilization combines chromosomes from each parent into resulting zygote

9) Which of the following processes best describes the mechanism of gamete production in plants?

gametophytes produce gametes by mitosis

51) During which of the following processes does independent assortment of chromosomes occur?

in meiosis I only

13) In a human karyotype, chromosomes are arranged in 23 pairs. If one of the autosomal pairs is examined, which of the following characteristics will the two chromosomes of the pair have in common?

loci and staining pattern

44) Crossing over of chromosomes normally takes place during which of the following processes?

meiosis I

46) During which of the following processes do homologous pairs of chromosomes align adjacent to one another at the metaphase plate of a cell?

metaphase I of meiosis

3) Asexual reproduction occurs during which of the following processes?

mitosis

26) Which of the following processes has just occurred when chiasmata can first be viewed under a microscope?

prophase I

57) Which of the following processes facilitates the fastest way for animal species to adapt to a changing environment?

sexual reproduction

25) Which of the following processes occurs in meiosis but not in mitosis?

synapsis of chromosomes

2) Which of the following phrases defines the term genome?

the complete set of an organism's genes and other DNA sequences

53) Independent assortment of chromosomes is a result of which of the following processes?

the random way each pair of homologous chromosomes lines up at the metaphase plate during meiosis I

39) Somatic cells of roundworms have four individual chromosomes per cell. How many chromosomes would you expect to find in an ovum from a roundworm?

two

49) A (hypothetical) diploid organism has different genes that control wing length and wing color.

1/2 of the eggs will have alleles for short blue-colored wings and 1⁄2 will have alleles for short orange-colored wings

4) Quaking aspen trees usually reproduce by extending underground stems that then push aboveground and grow into trees. Sexual reproduction is not as common, but when it does happen, the haploid gametes have 19 chromosomes. How many chromosomes are in the cells of the underground stems?

38

6) The figure represents the nucleus of an animal cell about to enter mitosis. How many different chromosomes are present in the diagram?

4

10) Which of the following statements describes an example of alternation of generations?

A diploid plant (sporophyte) produces a spore by meiosis that gives rise to a multicellular, haploid pollen grain (gametophyte).