Chapter 8: Sexual Reproduction and HeredityMultiple-Choice Questions1. Introduction; p. 153, Fig. 8-1; easy; ans: cBy crossing different varieties of peas ______ discovered the principles of heredity.a. William Batesonb. Walter Suttonc. Gregor Mendeld. Hugo de Vriese. Barbara McClintock2. Sexual Reproduction; p. 153; moderate; ans: aWhich of the following statements about sexual reproduction is FALSE?a. It is the principal mode of reproduction in prokaryotes.b. Some eukaryotes do not reproduce sexually.c. It involves the reduction of chromosome number.d. It involves syngamy.e. It involves a regular alternation between meiosis and fertilization.3. Sexual Reproduction; p. 153; moderate; ans: dWhich of the following statements about homologous chromosomes is FALSE?a. Both homologs are present in a zygote.b. One homolog comes from one parent and the other homolog from the other parent.c. Homologs resemble each other in the kinds of hereditary information they contain.d. Homologs resemble each other in size but not in shape.e. Homologs constitute a member of a pair. 4. The Eukaryotic Chromosome; p. 154; difficult; ans: eChromatin consists of:a. DNA only.b. histones only.c. DNA and histones only.d. histones and other proteins only.e. DNA, histones, and other proteins.5. The Eukaryotic Chromosome; pp. 154-155; easy; ans: bWhich of the following statements concerning histones is FALSE?a. They are responsible for the folding of DNA.b. They are present in four distinct types.c. They are always present in chromatin.d. They are synthesized during the S phase of the cell cycle.e. They are positively charged.6. The Eukaryotic Chromosome; p. 155; easy; ans: eA nucleosome consists of:a. nonhistone chromosomal proteins.b. eight histone molecules arranged in a spherical mass.c. a strand of DNA that is not associated with histones.d. a looped domain in the chromosome.e. a core of histones wrapped with DNA.7. The Process of Meiosis; p. 156; easy; ans: cA cell that unites with another cell is called a:a. meiospore.b. mitospore.c. gamete.d. diploid cell.e. zygote.8. The Process of Meiosis; p. 156; moderate; ans: aThe pairing of homologous chromosomes is called:a. synapsis.b. chiasma.c. crossing-over.d. recombination.e. bivalence.9. The Process of Meiosis; p. 156; moderate; ans: a Which of the following statements about the synaptonemal complex is FALSE?a. It forms just before prophase.b. It is associated with the formation of bivalents.c. It connects the axial cores of homologs.d. It disappears during prophase I.e. It is associated with crossing-over.10. The Process of Meiosis; p. 156; easy; ans: eCrossing-over occurs during:a. prophase II.b. metaphase I.c. telophase I.d. metaphase II.e. prophase I.11. The Process of Meiosis; p. 157; easy; ans: c Homologous pairs of chromosomes separate during:a. prophase II.b. metaphase I.c. anaphase I.d. metaphase II.e. anaphase III.12. The Process of Meiosis; p. 158; moderate; ans: aNuclear envelopes form around single-stranded chromosomes during:a. telophase II.b. metaphase I.c. prophase I.d. telophase I.e. metaphase II.13. The Process of Meiosis; p. 158; moderate; ans: dUnpaired double-stranded chromosomes line up on the equatorial plane during:a. prophase II.b. metaphase I.c. anaphase I.d. metaphase II.e. anaphase II.14. The Process of Meiosis; p. 158; moderate; ans: eSister chromatids become daughter chromosomes during:a. prophase II.b. metaphase I.c. anaphase I.d. metaphase II.e. anaphase II.15. The Process of Meiosis; p. 158; moderate; ans: dIf a cell has three pairs of homologous chromosomes, in how many ways could they be distributed among the haploid cells produced by meiosis?a. twob. threec. fourd. eighte. nine16. How Characteristics Are Inherited; pp. 159-160; moderate; ans: cWhich of the following statements about alleles is FALSE?a. They are different forms of the same gene.b. Interactions between alleles determine the characteristics of diploid organisms.c. They occupy different sites on homologous chromosomes.d. The site of an allele is called its locus.e. Dominant alleles are represented by uppercase letters, recessive alleles by lowercase letters.17. How Characteristics Are Inherited; p. 160; difficult; ans: cThe seeds of all the progeny of a cross between yellow-seeded plants and green-seeded plants are as yellow as those of the yellow-seeded parent. From this information, it is clear that:a. this is an example of a dihybrid cross.b. the F1 generation consists entirely of yellow-seeded plants.c. the F2 generation consists entirely of yellow-seeded plants.d. green is a dominant characteristic.e. yellow is a recessive characteristic.18. How Characteristics Are Inherited; p. 160; difficult; ans: dWhen a particular trait appears in the F2 generation but not in the F1 generation, it is an indication that:a. a monohybrid cross is involved.b. a dihybrid cross is involved.c. true-breeding plants are involved.d. the trait is recessive.e. the trait is dominant.19. How Characteristics Are Inherited; p. 162; moderate; ans: aIf we say that the phenotype of an individual is purple, we are saying that:a. the appearance of the individual is purple.b. the genetic constitution of the individual is purple.c. the individual is homozygous.d. the individual is heterozygous.e. purple is the dominant allele.20. How Characteristics Are Inherited; p. 162; moderate; ans: eIf the allele for red flower color is dominant over the allele for white flower color, which of the following represents a cross between a white-flowered plant and a plant heterozygous for flower color?a. RR × RRb. RR × Rrc. RR × rrd. Rr × Rre. Rr × rr21. How Characteristics Are Inherited; p. 162; moderate; ans: cIn peas, green pod color is dominant over yellow pod color. If a plant heterozygous for pod color is crossed with a plant homozygous recessive for pod color, what phenotypes would you expect in the offspring?a. all with green podsb. all with yellow podsc. half with green pods and half with yellow podsd. three-quarters with green pods and 1/4 with yellow podse. one-quarter with green pods and 3/4 with yellow pods22. How Characteristics Are Inherited; p. 162; moderate; ans: cIn peas, tall stem length is dominant over short length. What genotypic ratio would you expect in theoffspring of a cross between a heterozygous tall plant and a homozygous short plant?a. three homozygous tall: one homozygous short b. one homozygous tall: one homozygous shortc. one heterozygous tall: one homozygous