Exam 4

B

When chiasmata can first be seen in cells using a microscope, which of the following processes has most likely occurred? A. meiosis II B. prophase I C. anaphase II D. the separation of homologs

A

Which of the following characteristics do homologous chromosomes exhibit? A. They carry information for the same traits. B. They carry information for different traits. C. They align on the metaphase plate in meiosis II. D. They carry the same alleles.

C

Which of the life cycles is typical for most fungi and some protists? A. III only B. I only C. II only D. I and II

A

A certain (hypothetical) organism is diploid, has either blue or orange wings as the consequence of one of its genes on chromosome 12, and has either long or short antennae as the result of a second gene on chromosome 19, as shown in the figure. Chromosome 12 is shown as blue or orange; Chromosome 19 as either long or short. If a female of this species has one chromosome 12 with a blue gene and another chromosome 12 with an orange gene, and has both number 19 chromosomes with short genes, which of the following combinations of genes will her eggs have? A. one half blue short and one half orange short gene eggs B. three fourths blue short and one fourth orange short gene eggs C. only blue short gene eggs D. only orange short gene eggs

B

A certain (hypothetical) organism is diploid, has either blue or orange wings as the consequence of one of its genes on chromosome 12, and has either long or short antennae as the result of a second gene on chromosome 19, as shown in the figure. Chromosome 12 is shown as blue or orange; Chromosome 19 as either long or short. If a female of this species has one chromosome 12 with a blue gene and another chromosome 12 with an orange gene, and has both number 19 chromosomes with short genes, which of the following combinations of genes will her eggs have? A. only orange short gene eggs B. one half blue short and one half orange short gene eggs C. only blue short gene eggs D. three fourths blue short and one fourth orange short gene eggs

D

A human cell containing 22 autosomes and a Y chromosome is A. a zygote. B. a somatic cell of a male. C. an egg. D. a sperm.

A

During which of the following processes does independent assortment of chromosomes occur? A. in meiosis I only B. in meiosis II only C. in mitosis and meiosis I D. in mitosis and meiosis II

C

If we continue to follow the cell lineage from question 4, then the DNA content of a single cell at metaphase of meiosis II will be A. 0.5x. B. x. C. 2x. D. 0.25x.

A

Imagine that there are 25 different species of protists living in a tide pool. Some of these species reproduce both sexually and asexually, and some of them can reproduce only asexually. The pool gradually becomes infested with disease-causing viruses and bacteria. Which species are more likely to thrive in the changing environment? A. The sexually reproducing species is likely to thrive. B. The asexually reproducing species is likely to thrive. C. Sexually and asexually reproducing species are equally likely to thrive. D. Neither species will be able to thrive.

A

Quaking aspen trees can send out underground stems for asexual reproduction. 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? A. 38 B. 9 C. 19 D. 10

D

The somatic cells of a privet shrub 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? A. Privet shrub cells cannot reproduce sexually. B. Privet shrub sex cells have chromosomes that can synapse with human chromosomes in the laboratory. C. Privet shrubs must be metabolically more like animals than like other shrubs. D. Genes of privet shrub chromosomes are significantly different than those in humans.

C

The two homologs of a pair move toward opposite poles of dividing cell during A. mitosis. B. fertilization. C. meiosis I. D. meiosis II.

D

Refer to the information and figure below to answer the following questions. A certain (hypothetical) organism is diploid, has either blue or orange wings as the consequence of one of its genes on chromosome 12, and has either long or short antennae as the result of a second gene on chromosome 19, as shown in the figure. Chromosome 12 is shown as blue or orange; Chromosome 19 as either long or short. A certain female's number 12 chromosomes both have the blue gene and number 19 chromosomes both have the long gene. As cells in her ovaries undergo meiosis, which of the following combinations of genes and chromosomes will her eggs have? A. either one blue or one orange gene in addition to either one long or one short gene B. either two number 12 chromosomes with blue genes or two with orange genes C. either two number 19 chromosomes with long genes or two with short genes D. one chromosome 12 with one blue gene and one chromosome 19 with one long gene

C

Refer to the information and figure below to answer the following questions. A certain (hypothetical) organism is diploid, has either blue or orange wings as the consequence of one of its genes on chromosome 12, and has either long or short antennae as the result of a second gene on chromosome 19, as shown in the figure. Chromosome 12 is shown as blue or orange; Chromosome 19 as either long or short. A female with a paternal set of one orange and one long gene chromosome and a maternal set comprised of one blue and one short gene chromosome would be expected to produce which of the following types of eggs after meiosis? A. All eggs will have paternal types of gene combinations. B. All eggs will have maternal types of gene combinations. C. Each egg has a one-fourth chance of having either blue long, blue short, orange long, or orange short combinations. D. Half the eggs will have maternal and half will have paternal combinations.

B

Which of the following processes might produce a human zygote with 45 chromosomes? A. failure of an egg to complete meiosis II B. an error in meiotic anaphase occurring in either an egg or sperm C. incomplete cytokinesis during spermatogenesis after meiosis I D. failure of the egg nucleus to be fertilized by the sperm

B

Which of the following processes occur during meiosis but not mitosis? A. Haploid cells fuse to form diploid cells. B. Diploid cells form haploid cells. C. Haploid cells multiply into more haploid cells. D. A diploid cell combines with a haploid cell.

A

Which of the following processes occurs when homologous chromosomes cross over in meiosis I? A. Corresponding segments of non-sister chromatids are exchanged. B. Maternal alleles are "corrected" to be like paternal alleles and vice versa. C. Two sister chromatids get tangled, resulting in one re-sequencing its DNA. D. Two sister chromatids exchange identical pieces of DNA.

B

Which of the following statements correctly describes a karyotype? A. It is a display of a cell's mitotic stages. B. It is an organized image of a cell's chromosomes. C. It reveals the appearance of an organism. D. It is a display of all of the cell types in an organism.

D

Which of the following statements defines a genome? A. a karyotype B. the complete set of a species' polypeptides C. the complete set of an organism's polypeptides D. the complete set of an organism's genes and other DNA sequences

B

Which of the following statements describes a major difference between meiosis II and mitosis in a diploid animal?A. Sister chromatids separate in mitosis, and homologous chromosomes separate in meiosis II. B. Meiosis II occurs in a haploid cell, while mitosis occurs in diploid cells. C. Homologous chromosomes align on the metaphase plate in meiosis II. D. Crossing over of chromosomes takes place in meiosis II.

B

Which of the following statements describes a major difference between mitosis and meiosis I in a diploid organism? A. Only meiosis I results in daughter cells that contain identical genetic information. B. Sister chromatids separate in mitosis, while homologous pairs of chromosomes separate in meiosis I. C. Sister chromatids separate in mitosis, while homologous pairs of chromosomes separate in meiosis II. D. DNA replication takes place prior to mitosis, but not before meiosis I.

A

Which of the following statements describes an example of alternation of generations? A. A diploid plant (sporophyte) produces a spore by meiosis that gives rise to a multicellular, haploid pollen grain (gametophyte). B. A grandparent and grandchild each have dark hair, but the parent has blond hair. 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.

B

Which of the following statements describes the chromosomal makeup of each daughter cell after telophase of meiosis I? A. The cells are haploid, and the chromosomes are each composed of a single chromatid. B. The cells are haploid, and the chromosomes are each composed of two chromatids. C. The cells are diploid, and the chromosomes are each composed of a single chromatid. D. The cells are diploid, and the chromosomes are each composed of two chromatids.

D

Which of the following statements is correct regarding the human X chromosomes? A. It is the same size as other chromosomes and has the same number of genes. B. It is present in every somatic cell of males and females. C. It is referred to as an autosome. D. It carries genes that determine an individual's biological sex.

C

Which of the following statements is true of a species that has a chromosome number of 2n = 16? A. The species has 16 sets of chromosomes per cell. B. A gamete from this species has four chromosomes. C. Each diploid cell has eight homologous pairs of chromosomes. D. The species is diploid with 32 chromosomes per cell.

B

Which of the following statements is true of a species that has a chromosome number of 2n = 16? A. The species is diploid with 32 chromosomes per cell. B. Each diploid cell has eight homologous pairs of chromosomes. C. The species has 16 sets of chromosomes per cell. D. A gamete from this species has four chromosomes.

D

Which of the life cycles is typical for plants and some algae? A. II only B. I only C. I and III D. III only

C

Crossing over of chromosomes normally takes place during which of the following processes? A. mitosis B. meiosis II C. meiosis I D. mitosis and meiosis II

A

DNA was isolated from three different cell types of the same organism, the relative DNA content for each type was determined, and the results were plotted on the graph shown in the figure below. Refer to the graph to answer the following questions. Which sample of DNA might represent an animal cell in the G2 phase of the cell cycle prior to meiosis? A. II B. I C. III D. both I and II

A

During which of the following phases of meiosis do centromeres split and sister chromatids migrate to opposite poles of the cell? A. anaphase II B. anaphase I C. telophase II D. telophase I

B

During which of the following phases of meiosis do homologous chromosomes separate? A. mitosis B. anaphase I C. anaphase II D. prophase I

A

During which of the following processes do homologous pairs of chromosomes align adjacent to one another at the metaphase plate of a cell? A. metaphase I of meiosis B. telophase II of meiosis C. metaphase II of meiosis D. metaphase of mitosis

C

During which of the following processes do sister chromatids separate from each other? A. during meiosis II only B. during both mitosis and meiosis I C. during both mitosis and meiosis II D. during meiosis I only

B

Eukaryotic sexual life cycles show tremendous variation. Which of the following characteristics do all sexual life cycles have in common? I. Alternation of generations II. Meiosis III. Fertilization IV. Gametes V. Spores A. I, II, and IV B. II, III, and IV C. II, IV, and V D. I, II, III, IV, and V

B

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? A. about 1,000 B. about 8 million C. 23 D. 46

B

For the following questions, 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 Centromeres of sister chromatids disjoin and chromatids separate. A. III B. VII C. V D. IV

B

Genetic variation leads to genetic diversity in populations and is the raw material for evolution. Biological systems have multiple processes, such as reproduction, that affect genetic variation. They are evolutionarily conserved and shared by various organisms. Which of the following statements best represents the connection between reproduction and evolution? A. Plants that use sexual reproduction are rare since this type of reproduction in plants does not contribute to genetic diversity. B. Sexual reproduction increases genetic variation because random mutations can be shuffled between organisms. C. Since prokaryotic organisms reproduce asexually, there is no mechanism for them to add genetic diversity for evolution. D. In order to increase genetic diversity for evolution in sexually reproducing organisms, mutations must occur in the zygote after fertilization.

D

If a horticulturist breeding gardenias succeeds in having a single plant with a particularly desirable set of traits, which of the following would be her most probable and efficient route to establishing a line of such plants? A. Force the plant to self-pollinate to obtain an identical one. B. Backtrack through her previous experiments to obtain another plant with the same traits. C. Breed this plant with another plant with much weaker traits. D. Clone the plant.

A

In a life cycle such as that shown in part III of the figure above, if the zygote's chromosome number is ten, which of the following statements will be true? A. The sporophyte's chromosome number per cell is ten and the gametophyte's is five. B. The sporophyte and gametophyte each have five chromosomes per cell. C. The sporophyte and gametophyte each have ten chromosomes per cell. D. The sporophyte's chromosome number per cell is five and the gametophyte's is ten.

A

In eukaryotes, genetic information is passed to the next generation by processes that include mitosis or meiosis. Which of the following explanations correctly identifies the process and supports the claim that heritable information is passed from one generation to another? A. In asexual reproduction, a single individual is the sole parent and passes copies of its genes to its offspring without the fusion of gametes. B. During mitosis, DNA replication occurs twice within the cell cycle to insure a full set of chromosomes within each of the daughter cells produced. C. Single-celled organisms can fuse their cells, reproducing asexually through mitosis to form new cells that are not identical to the parent cell. D. Mitosis, followed by cytokinesis, produces daughter cells that are genetically different from the parent cell, thus insuring variation within the population.

B

Meiosis II is similar to mitosis in that A. the daughter cells are diploid. B. sister chromatids separate during anaphase. C. homologous chromosomes synapse. D. DNA replicates before the division.

D

A particular organism has 46 chromosomes in its karyotype. Which of the following statements is correct regarding this organism? A. It must be human. B. It must be an animal. C. It reproduces sexually. D. It produces gametes with 23 chromosomes.

C

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

A

At which stage of mitosis are chromosomes usually photographed in the preparation of a karyotype? A. metaphase B. prophase C. anaphase D. interphase