Meiosis Review

  1. If 2n = 14, how many chromosomes will be present in somatic cells? a. ______How many chromosomes will be found in gametes? b. ______If n = 14, how many chromosomes will be found in diploid somatic cells? c. ______How many sets of homologous chromosomes will be found in gametes? d. ______
  1. How many assortments of maternal and paternal chromosomes are possible in human gametes?
  1. The following diagrams represent some of the stages of meiosis (not in the right order). Label these stages.

a.b.c. d.e. f.

  1. Place these stages in the proper sequence:

______

  1. Describe the key events of these stages of meiosis.

a. Interphase I / d. Anaphase I
b. Prophase I / e. Metaphase II
c. Metaphase I / f. Anaphase II

For a diploid cell (2n=6), sketch the chromosomes as they would appear in the following stages of mitosis or meiosis:

  1. Metaphase (mitosis)9. Anaphase I
  1. Metaphase II10. Telophase I
  1. Anaphase (mitosis)11. Telophase II
  1. The restoration of the diploid chromosome number after halving in meiosis is due
  2. synapsis.b. fertilizationc. mitosisd. DNA replication

e. chiasmata.

  1. What is a karyotype?
  2. a genotype of an individual
  3. a unique combination of chromosomes foundin a gamete
  4. a blood type determination of an individual
  5. a pictorial display of an individual's chromosomes
  6. species-specific diploid number of chromosomes
  1. What are autosomes?
  2. sex chromosomes
  3. chromosomes that occur singly
  4. chromosomal abnormalities that result in geneticeffects
  5. chromosomes found in mitochondria andchloroplasts
  6. none of the above
  1. A synaptonemal complex would be found during
  2. prophase I of meiosis.b. fertilization of gametes

c. metaphase II of meiosis.d. prophase of mitosis.

e. anaphase I of meiosis.

  1. During the first meiotic division (meiosis I),
  2. homologous chromosomes separate.
  3. the chromosome number becomes haploid.
  4. crossing over between nonsister chromatidsoccurs.
  5. paternal and maternal chromosomes assortrandomly.
  6. all of the above occur.
  1. A cell with a diploid number of 6 could produce gametes with how many different combinations of maternal and paternal chromosomes?

a.6 b.8 c. 12 d.64 e. 128

  1. The DNA content of a cell is measured in the G2 phase. After meiosis I, the DNA content of one of the two cells produced would be
  2. equal to that of the G2 cell.
  3. twice that of the G2 cell. .
  4. one-half that of the G2 cell.
  5. one-fourth that of the G2 cell.
  6. impossible to estimate due to independent assortment of homologous chromosomes.
  7. Which of the following is not a source of genetic variation in sexually reproducing organisms?
  8. crossing over
  9. replication of DNA during S phase beforemeiosis I
  10. independent assortment of chromosomes
  11. random fertilization of gametes
  12. mutation
  1. Meiosis II is similar to mitosis because
  2. sister chromatids separate.
  3. homologous chromosomes separate.
  4. DNA replication precedes the division.
  5. they both take the same amount of time.
  6. haploid cells are produced.
  7. Homologous chromosomes
  8. have identical genes.
  9. have genes for the same traits at the same loci.
  10. are found in gametes.
  11. separate in meiosis II.
  12. have all of the above characteristics.
  1. Asexual reproduction of a diploid organism would
  2. be impossible.
  3. involve meiosis.
  4. produce identical offspring.
  5. show variation among sibling offspring.
  6. involve spores produced by meiosis.
  7. In a sexually reproducing species with a diploid number of 8, how many different combinations of paternal and maternal chromosomes would be possible in the offspring?
  8. 8 b. 16 c. 64d. 256e. 512
  9. The calculation of offspring in question 23 includes only variation resulting from
  10. crossing over.
  11. random fertilization.
  12. independent assortment of chromosomes.
  13. a, b, and c.
  14. only band c.
  15. How many chromatids are present in metaphase II in a cell undergoing meiosis from an organism in which 2n = 24?
  16. 12 b. 24c. 36d. 48e. 96
  1. Which of the following would not be considered a haploid cell?
  2. daughter cell after meiosis II
  3. gamete
  4. daughter cell after mitosis in gametophyte generation of a plant
  5. cell in prophase I
  6. cell in prophase II
  7. Which of the following is not true of homologous chromosomes?
  8. They behave independently in mitosis.
  9. They synapse during the S phase of meiosis.
  10. They travel together to the metaphase plate inprometaphase of meiosis 1.
  11. Each parent contributes one set of homologouschromosomes to an offspring.
  12. Crossing over between nonsister chromatids ofhomologous chromosomes is indicated by thepresence of chiasmata.
  1. Which of the following describes why or how recombinant chromosomes add to genetic variability?
  2. They are formed as a result of random fertilization when two sets of chromosomes combine in a zygote. .
  3. They are the result of mutations that changealleles.
  4. They randomly orient during metaphase II andthe nonequivalent sister chromatids separate inanaphase II.
  5. Genetic material from two parents is combinedon the same chromosome.
  6. Both c and d are true.
  7. A cell in G2 before meiosis compared with one of the four cells produced by that meiotic division has
  8. twice as much DNA and twice as many chromosomes.
  9. four times as much DNA and twice as manychromosomes.
  10. four times as much DNA and four times as many chromosomes.
  11. half as much DNA but the same number of chromosomes
  12. half as much DNA and half as many chromosomes