Biology 101 Exam #2 (Mitosis/Meiosis, CH8)

A diploid organism whose somatic (nonsex) cells each contain 32 chromosomes produces gametes containing _____ chromosomes. 1. 16 2. 64 3. 32 4. 8 5. 30

1

During _____ chromosomes align single file along the equator of a haploid cell. metaphase II telophase I and cytokinesis metaphase I prophase I anaphase I

1

During _____ sister chromatids separate. 1. anaphase II 2. prophase II 3. interphase 4. metaphase I 5. prophase I

1

Meiosis I produces _____ cells, each of which is _____. 1. two ... haploid 2. two... identical to the other 3. four ... diploid 4. two... diploid 5. four ... haploid

1

The bulldog ant has a diploid number of two chromosomes. Therefore, following meiosis, each daughter cell will have a single chromosome. In addition to mutations, how might genetic diversity be generated in this species? 1. crossing over and random fertilization 2. crossing over only 3. independent assortment only 4. nothing else

1

What number and types of chromosomes are found in a human somatic cell? See Concept 13.2 ( page 256) Hints 1. 44 autosomes and 2 sex chromosomes 2. 21 autosomes and 2 sex chromosomes 3. 22 autosomes and 1 sex chromosome 4. n chromosomes 5. 45 autosomes and 1 sex chromosome

1

Which of the following events happens at the conclusion of meiosis I? 1. Homologous chromosomes of a pair are separated from each other. 2. Four daughter cells are formed. 3. Sister chromatids are separated. 4. The chromosome number per cell remains the same.

1

Which of the following statements defines a genome? 1. the complete set of an organism's genes and other DNA sequences 2. the complete set of an organism's polypeptides 3. the complete set of a species' polypeptides 4. a karyotype

1

Which of the following statements describes the chromosomal makeup of each daughter cell after telophase of meiosis I? 1. The cells are haploid, and the chromosomes are each composed of two chromatids. 2. The cells are haploid, and the chromosomes are each composed of a single chromatid. 3. The cells are diploid, and the chromosomes are each composed of two chromatids. 4. The cells are diploid, and the chromosomes are each composed of a single chromatid.

1

Which processes lead to most genetic variation in sexually reproducing organisms? Select all that apply. 1. crossing over 2. cytokinesis 3. random fertilization 4. independent assortment of chromosomes in meiosis

1, 3 ,4

At the end of _____ and cytokinesis, haploid cells contain chromosomes that each consist of two sister chromatids. interphase telophase I telophase II telophase metaphase II

2

Crossing over of chromosomes normally takes place during which of the following processes? 1. meiosis II 2. meiosis I 3. mitosis 4. mitosis and meiosis II

2

During which of the following phases of meiosis do centromeres split and sister chromatids migrate to opposite poles of the cell? 1. telophase I 2. anaphase II 3. telophase II 4. anaphase I

2

During which of the following processes do homologous pairs of chromosomes align adjacent to one another at the metaphase plate of a cell? 1. metaphase of mitosis 2. metaphase I of meiosis 3. metaphase II of meiosis 4. telophase II of meiosis

2

During which of the following processes do sister chromatids separate from each other? 1. during both mitosis and meiosis I 2. during both mitosis and meiosis II 3. during meiosis II only 4. during meiosis I only

2

Homologous chromosomes migrate to opposite poles during _____. 1. metaphase I 2. anaphase I 3. telophase II and cytokinesis 4. prophase II 5. metaphase II

2

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? 1. The asexually reproducing species is likely to thrive. 2. The sexually reproducing species is likely to thrive. 3. Sexually and asexually reproducing species are equally likely to thrive. 4. Neither species will be able to thrive

2

Measurements of the amount of DNA per nucleus were taken on a large number of cells from a growing fungus. The measured DNA levels ranged from 3 to 6 picograms (pg) per nucleus. During the entirety of which stage of the cell cycle did the nucleus contain 6 pg of DNA? M G2 G1 S

2

Meiosis II is similar to mitosis in that 1. the chromosome number is reduced. 2. sister chromatids separate during anaphase. 3. DNA replicates before the division. 4. the daughter cells are diploid. 5. homologous chromosomes synapse.

2

The shuffling of chromosomes that occurs during both fertilization and _____ can lead to genetic variation. See Concept 13.4 ( page 265) Hints 1. natural selection 2. meiosis 3. genetic drift 4. mitosis 5. mutation

2

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? 1. Privet shrub sex cells have chromosomes that can synapse with human chromosomes in the laboratory. 2. Genes of privet shrub chromosomes are significantly different than those in humans. 3. Privet shrubs must be metabolically more like animals than like other shrubs. 4. Privet shrub cells cannot reproduce sexually.

2

Which of the following characteristics do homologous chromosomes exhibit? 1. They carry the same alleles. 2. They carry information for the same traits. 3. They align on the metaphase plate in meiosis II. 4. They carry information for different traits.

2

Which of the following phases make up the stages of mitosis? 1. Prophase, prometaphase, metaphase, anaphase, telophase, and cytokinesis 2. Prophase, prometaphase, metaphase, anaphase, and telophase 3. Interphase 4. G1, S, and G2

2

Which of the following statements describes a major difference between meiosis II and mitosis in a diploid animal? 1. Homologous chromosomes align on the metaphase plate in meiosis II. 2. Meiosis II occurs in a haploid cell, while mitosis occurs in diploid cells. 3. Sister chromatids separate in mitosis, and homologous chromosomes separate in meiosis II. 4. Crossing over of chromosomes takes place in meiosis II.

2

Which of the following statements describes a major difference between mitosis and meiosis I in a diploid organism? 1. DNA replication takes place prior to mitosis, but not before meiosis I. 2. Sister chromatids separate in mitosis, while homologous pairs of chromosomes separate in meiosis I. 3. Sister chromatids separate in mitosis, while homologous pairs of chromosomes separate in meiosis II. 4. Only meiosis I results in daughter cells that contain identical genetic information.

2

Synapsis occurs during _____. metaphase II telophase I and cytogenesis prophase I prophase II anaphase II

3

Asexual reproduction occurs during which of the following processes? 1. the exchange of chromosomes between organisms of different species 2. meiosis 3. mitosis 4. fertilization

3

How do cells at the completion of meiosis compare with cells that are in prophase of meiosis I? 1. The cells have the same number of chromosomes and half the amount of DNA. 2. The cells have half the amount of cytoplasm and twice the amount of DNA. 3. The cells have half the number of chromosomes and one-fourth the amount of DNA. 4. The cells have half the number of chromosomes and half the amount of DNA.

3

Human gametes are produced by _____. 1. asexual reproduction 2. the cell cycle 3. meiosis 4. fertilization 5. mitosis

3

If a cell has completed meiosis I and the first cytokinesis, and is just beginning meiosis II, which of the following is an appropriate description of its genetic contents? 1. It has one-fourth the DNA and one-half the chromosomes as the parent cell. 2. It has half the chromosomes but twice the DNA of the parent cell. 3. It has half the amount of DNA as the cell that began meiosis. 4. It is genetically identical to another cell formed from the same meiosis I event.

3

Two sister chromatids are joined at the centromere prior to meiosis. Which statement is correct? 1. These chromatids make up a diploid chromosome. 2. The cell that contains these sister chromatids must be haploid. 3. Barring mutation, the two sister chromatids must be identical.

3

What must happen to a chromosome before a cell starts mitosis? 1. The chromatin of the chromosome must be completely condensed. 2. The two chromatids of the chromosome must become attached to each other. 3. The single DNA molecule in the chromosome must be replicated. 4. Both molecules of DNA in the chromosome must be replicated.

3

Which of the following events characterizes metaphase of mitosis? 1. movement of the chromosomes toward the equator 2. condensing of the DNA into discrete chromosomes 3. alignment of the chromosomes at the equator 4. separation of sister chromatids

3

Which of the following processes occur during meiosis but not mitosis? 1. A diploid cell combines with a haploid cell. 2. Haploid cells multiply into more haploid cells. 3. Diploid cells form haploid cells. 4. Haploid cells fuse to form diploid cells.

3

Which of the following processes occurs when homologous chromosomes cross over in meiosis I? 1. Maternal alleles are "corrected" to be like paternal alleles and vice versa. 2. Two sister chromatids exchange identical pieces of DNA. 3. Corresponding segments of non-sister chromatids are exchanged. 4. two sister chromatids get tangled, resulting in one re-sequencing its DNA.

3

Which of the following statements is true of a species that has a chromosome number of 2n = 16? 1. The species is diploid with 32 chromosomes per cell. 2. A gamete from this species has four chromosomes. 3. Each diploid cell has eight homologous pairs of chromosomes. 4. The species has 16 sets of chromosomes per cell.

3

At the end of _____ and cytokinesis there are four haploid cells. prophase I prophase II interphase telophase II anaphase I

4

During _____ a spindle forms in a haploid cell. prophase I telophase I and cytokinesis metaphase II prophase II anaphase II

4

During which of the following phases of meiosis do homologous chromosomes separate? 1. mitosis 2. prophase I 3. anaphase II 4. anaphase I

4

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. 1. III 2. IV 3. V 4. VII

4

I. Prophase I V. Prophase II II. Metaphase I VI. Metaphase II III. Anaphase I VII. Anaphase II IV. Telophase I VIII. Telophase II Homologous chromosomes are aligned at the equator of the spindle. 1. IV 2. VI 3. I 4. II

4

If the DNA content of a diploid cell in the G1 phase of the cell cycle is x, then the DNA content of the same cell at metaphase of meiosis I would be 1. 0.5x. 2. 4x. 3. 0.25x. 4. 2x. 5. x.

4

If we continued to follow the cell lineage from question 4, then the DNA content of a single cell at metaphase of meiosis II would be 1. 4x. 2. 0.5x. 3. 0.25x. 4. x. 5. 2x.

4

Meiosis II typically produces _____ cells, each of which is _____. four ... identical to the other four ... diploid two... diploid four ... haploid two ... haploid

4

Normal human gametes carry _____ chromosomes. 1. 23 pairs of 2. 46 pairs of 3. 46 4. 23 5. 5

4

Somatic cells of roundworms have four individual chromosomes per cell. How many chromosomes would you expect to find in an ovum from a roundworm? 1. eight 2. a diploid number 3. four 4. two

4

The parent cell that enters meiosis is diploid, whereas the four daughter cells that result are haploid. Which statement correctly describes how cellular DNA content and ploidy levels change during meiosis I and meiosis II? Hints 1.DNA content is halved only in meiosis I. Ploidy level changes from diploid to haploid in meiosis I, and remains haploid in meiosis II. 2. DNA content is halved only in meiosis II. Ploidy level changes from diploid to haploid in meiosis I, and remains haploid in meiosis II. 3. DNA content is halved only in meiosis I. Ploidy level changes from diploid to haploid only in meiosis II. 4. DNA content is halved in both meiosis I and meiosis II. Ploidy level changes from diploid to haploid in meiosis I, and remains haploid in meiosis II. 5. DNA content is halved in both meiosis I and meiosis II. Ploidy level changes from diploid to haploid only in meiosis II.

4

The two homologs of a pair move toward opposite poles of a dividing cell during 1. mitosis. 2. meiosis II. 3. fertilization. 4. meiosis I.

4

What is crossing over? See Concept 13.3 ( page 262) Hints 1. the movement of genetic material from one chromosome to a nonhomologous chromosome 2. a direct consequence of the separation of sister chromatids 3. also referred to as the "independent assortment of chromosomes" 4. the exchange of homologous portions of nonsister chromatids 5. making an RNA copy of a DNA strand

4

When chiasmata can first be seen in cells using a microscope, which of the following processes has most likely occurred? 1. anaphase II 2. the separation of homologs 3. meiosis II 4. prophase I

4

Which of the following occurs during meiosis but not during mitosis? See Concept 13.3 ( page 262) Hints 1. Chromosomes migrate to opposite poles. 2. Chromosomes condense. 3. A spindle apparatus forms. 4. Synapsis occurs. 5. Chromosomes align at the metaphase plate

4

Which of the following processes occurs in meiosis but not in mitosis? 1. condensation of chromosomes 2. alignment of chromosomes at the equator 3. chromosome replication 4. synapsis of chromosomes

4

Which of the following statements describes one characteristic of each chromosome in a cell during the entire process of meiosis I? 1. Each chromosome consists of a single strand of DNA. 2. Each chromosome is paired with a homologous chromosome. 3. Each chromosome is joined with its homologous pair to form a synaptonemal complex. 4. Each chromosome consists of two sister chromatids joined by a centromere.

4

Heritable variation is required for which of the following? See Concept 13.4 ( page 266) Hints 1. asexual reproduction 2. mitosis 3. the production of a clone 4. meiosis 5. evolution

5

How are sister chromatids and homologous chromosomes different from each other? See Concept 13.2 ( page 257) Hints 1. They are not different. Homologous chromosomes and sister chromatids are both identical copies of each other. 2. Homologous chromosomes are closely associated with each other in both mitosis and meiosis. Sister chromatids are only associated with each other during mitosis. 3. Homologous chromosomes are identical copies of each other. One sister chromatid comes from the father, and one comes from the mother. 4. Sister chromatids are only formed during mitosis. Homologous chromosomes are formed during meiosis. 5. Homologous chromosomes contain the same gene loci but may have different alleles of a particular gene. Sister chromatids are identical copies of each other produced during DNA replication.

5

Mitosis results in the formation of how many cells; meiosis results in the formation of how many cells? See Concept 13.3 ( page 262) Hints 1. two diploid cells ... two haploid cells 2. four diploid cells ... four haploid cells 3. two diploid cells ... two diploid cells 4. four haploid cells ... two diploid cells 5. two diploid cells ... four haploid cells

5

Many organisms spend most of their life cycle in the diploid state. If meiosis produces haploid cells, how is the diploid number restored for these types of organisms? 1. by DNA replication 2. by fertilization 3. by synapsis of the homologous pairs of chromosomes during prophase of meiosis I 4. through the transcription of DNA to RNA

b