chapter 10

For the following question(s), match the key event of meiosis with the stages listed below. I. prophase I V. prophase IIII. metaphase I VI. metaphase IIIII. anaphase I VII. anaphase IIIV. telophase I VIII. telophase II Synaptonemal complexes form or are still present. a.I only b.I and IV only c.I and VIII only d.I, II, III, and IV only

a.I only

Which of the following types of cells would be produced by meiosis? a.a haploid animal cell b.a diploid plant cell c.a diploid animal cell d.a diploid unicellular organism

a.a haploid animal cell

To visualize and identify meiotic cells at metaphase I with a microscope, what would you look for? a.pairs of homologous chromosomes all aligned at the cell's center b.individual chromosomes all at the cell's center c.sister chromatids of a replicated chromosome grouped at the poles d.an uninterrupted spindle array Submit

a.pairs of homologous chromosomes all aligned at the cell's center

Which of the following events occurs in meiosis but not in mitosis? a.synapsis of chromosomes b.chromosome replication c.condensation of chromatin d.production of daughter cells

a.synapsis of chromosomes

Which of the following descriptions correctly defines a genome? a.the complete set of an organism's genes b.the complete set of an organism's polypeptides c.representation of a complete set of a cell's polypeptides d.a karyotype

a.the complete set of an organism's genes

The somatic cells of a privet shrub each contain 46 chromosomes. To be as different as they are from human cells, which have the same number of chromosomes, which of the following must be true? a.Genes on a particular privet chromosome, such as the X, must be on a different human chromosome, such as number 18. b.Genes of privet chromosomes are significantly different from those in humans. c.Privet cells cannot reproduce sexually. d.Privet shrubs must be metabolically more like animals than like other shrubs.

b.Genes of privet chromosomes are significantly different from those in humans.

For the following question(s), match the key event of meiosis with the stages listed below. I. prophase I V. prophase IIII. metaphase I VI. metaphase IIIII. anaphase I VII. anaphase IIIV. telophase I VIII. telophase II Homologous chromosomes are aligned at the equator of the spindle. a.I b.II c.IV d.VI

b.II

When homologous chromosomes cross over, what is the result? a.Each of the four DNA strands of a homologous pair is broken, and the pieces are mixed. b.Specific proteins break the two strands of nonsister chromatids and re-join them. c.Two sister chromatids get tangled, resulting in one altering the sequence of its DNA. d.Two sister chromatids exchange identical pieces of DNA.

b.Specific proteins break the two strands of nonsister chromatids and re-join them.

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 the same number of chromosomes and half the amount of DNA. b.They have half the number of chromosomes and one-fourth the amount of DNA. c.They have half the number of chromosomes and half the amount of DNA. d.They have half the amount of cytoplasm and twice the amount of DNA.

b.They have half the number of chromosomes and one-fourth the amount of DNA.

In a human karyotype, chromosomes are arranged in 23 pairs. If we choose one of these pairs, such as pair 14, which of the following do the two chromosomes of the pair have in common? a.length, centromere position, staining pattern, and DNA sequences b.length, centromere position, staining pattern, and traits coded for by their genes c.length and position of the centromere only d.length, centromere position, and staining pattern only

b.length, centromere position, staining pattern, and traits coded for by their genes

When we see chiasmata under a microscope, that lets us know that which of the following processes has occurred? a.meiosis II b.prophase I c.anaphase II d.separation of homologs

b.prophase I

Independent assortment of chromosomes during meiosis is a result of a.the random distribution of the sister chromatids to the two daughter cells during anaphase II. b.the random and independent way in which each pair of homologous chromosomes lines up at the metaphase plate during meiosis I. c.the random nature of the fertilization of ova by sperm. d.the relatively small degree of homology shared by the X and Y chromosomes.

b.the random and independent way in which each pair of homologous chromosomes lines up at the metaphase plate during meiosis I.

Which of the following happens during meiosis I? a.The chromosome number per cell is conserved. b.Four daughter cells are formed. c.Homologous chromosomes of a pair are separated from each other. d.Sister chromatids are separated.

c.Homologous chromosomes of a pair are separated from each other.

A given organism has 46 chromosomes in its karyotype. We can therefore conclude which of the following? a.It must be an animal. b.It must be human. c.Its gametes must have 23 chromosomes. d.It must be sexually reproducing.

c.Its gametes must have 23 chromosomes.

aIf an organism is diploid and a certain gene found in the organism has 18 known alleles (variants), then any given organism of that species can/must have which of the following? a.up to, but not more than, 18 different traits b.up to 18 chromosomes with that gene c.at most, 2 alleles for that gene d.up to 18 genes for that trait

c.at most, 2 alleles for that gene

At which stage of mitosis are chromosomes usually photographed in the preparation of a karyotype? a.telophase b.anaphase c.metaphase d.prophase

c.metaphase

For the following question(s), match the key event of meiosis with the stages listed below. I. prophase I V. prophase IIII. metaphase I VI. metaphase IIIII. anaphase I VII. anaphase IIIV. telophase I VIII. telophase II Centromeres of sister chromatids disjoin and chromatids separate. a.III b.IV c.V d.VII

d. VII

During mitosis or meiosis, sister chromatids are held together by proteins referred to as cohesins. Such molecules must have which of the following properties? a.They must be removed before meiosis can begin. b.They must persist throughout the cell cycle. c.They must be intact for nuclear envelope re-formation. d.They must be removed before sister chromatids or homologous chromosomes can separate.

d.They must be removed before sister chromatids or homologous chromosomes can separate.