Quiz 6

If a cell at metaphase of mitosis contains 32 sister chromatids, how many chromosomes will be present in a G1 cell? - 32 - 16 - 64 - 8

16

Beginning with a fertilized egg (zygote), how many cells will be present in the embryo following five rounds of cell division? - 6 - 32 - 10 - 16

32

In a diploid cell with four chromosome pairs (2n=8), how many centromeres will be found in a nucleus at G2 of the cell division cycle? - 4 - 16 - 32 - 8

8

Which of the following properties is associated with a cyclin-dependent kinase (Cdk)? - A Cdk is an enzyme that attaches phosphate groups to other proteins - A Cdk is inactive, or "turned off," in the presence of a cyclin - A Cdk is an enzyme that catalyzes the attachment of kinetochores to microtubules - The number of Cdk molecules during the S and G2 phases and decrease during M

A Cdk is an enzyme that attaches phosphate groups to other proteins

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

A diploid plant (sporophyte) produces a spore by meiosis that gives rise to a multicellular, haploid pollen grain (gametophyte).

Which of the following statements describes a characteristic feature of metaphase? - Separation of sister chromatids - Alignment of chromosomes on the equator of the cell - Cytokinesis - Separation of the centromeres

Alignment of chromosomes on the equator of the cell

For the following question, match the key event of meiosis with the stages listed below. Cohesions at centromeres of sister chromatids breakdown. - Telophase I - Anaphase I - Anaphase II - Prophase II

Anaphase II

Which of the following molecules is maintained at a relatively constant level throughout the cell cycle but requires a cyclin to become catalytically active? - MPF - PDGF - Cdk - Cyclin

Cdk

Taxol is an anticancer drug extracted from the Pacific yew tree. In animal cells, Taxol prevents microtubule depolymerization, which interferes with which of the following processes? - Cytokinesis - Chromosome condensation - Centriole duplication - Chromosome separation

Chromosome separation

Certain unicellular eukaryotes, including diatoms and some yeasts, have mechanisms of nuclear division that resemble intermediate steps in the evolution of mitosis. Which of the following is a characteristic feature of nuclear division in these organisms? - Chromosomes are segregated by attachment to the plasma membrane - Chromosomes are segregated by a mitotic spindle, but the nuclear envelope remains intact during division - They have circular chromosomes that are segregated by a mitotic spindle - They reproduce by binary fission in their early stages of development and by mitosis when they are mature

Chromosomes are segregated by a mitotic spindle, but the nuclear envelope remains intact during division

Which of the following molecules is synthesized at specific times during the cell cycle and forms an active complex with a kinase? - MPF - Cyclin - PDGF - Cdk

Cyclin

Which of the following pairs of molecules make up an active MPF? - A growth factor and mitotic factor - Cyclin and cyclin-dependent kinase - ATP synthetase and a protease - Cyclin and tubulin

Cyclin and a cyclin-dependent kinase

During which of the following processes do sister chromatids separate each other? - During meiosis I only - During meiosis II only - During both mitosis and meiosis I - During both mitosis and meiosis II

During both mitosis and meiosis II

Cell A has half as much DNA as cells B, C, and D in a mitotically active tissue. Cell A is most likely in ______. - G2 - G1 - Prophase - Metaphase

G1

Cells from a diploid protist with n=1 are followed through mitosis and meiosis. The drawings in the figure below represent the chromosomes. Refer to the drawings and answer the following question(s). - V - IV - II - I

I

Cells from a diploid protist with n=1 are followed through mitosis and meiosis. The drawings in the figure below represent the chromosomes. Refer to the drawings and answer the following question(s). Which diagram represents prophase of mitosis? - I - III - VI - IV

III

Amount of DNA per nucleus over the cell division cycle. Which numbered regions of the accompanying figure represent the DNA content associated with cells at metaphase? - IV only - II and IV - II only - III only

III only

Which of the following explanations describes a reproductive approach? - Mitosis, followed by cytokinesis, produces daughter cells that are genetically different from the parent cell, thus insuring variation within the population - Single-celled organisms can fuse their cells to form new cells that are not identical to the parent cell - In asexual reproduction, a single individual is the sole parent and passes copies of its genes to its offspring without the fusion of gametes - During mitosis, DNA replication occurs twice to insure each daughter cell contains a full set of chromosomes

In asexual reproduction, a single individual is the sole parent and passes copies of its genes to its offspring without the fusion of gametes

During which of the following processes does independent assortment of chromosomes occur? - In mitosis and meiosis I - In meiosis I only - In mitosis and meiosis II - In meiosis II only

In meiosis I only

Which of the following statements about reproduction is correct? - In a sexual reproduction, individuals transmit half of their nuclear genes to each of their offspring. - Asexual reproduction, but not sexual reproduction, is a characteristic of only plants and fungi. - In asexual reproduction, offspring are produced by fertilization without meiosis. - Asexual reproduction produces only haploid offspring

In sexual reproduction, individuals transmit half of their nuclear genes to each of their offspring

Students in a biology lab isolated cells in various phases of the cell cycle. A population of cells that have 1 1/2 times the DNA of G1 phase cells was most likely isolated from which of the following part of the cell cycle? - In the G2 phase - In the M phase - Between the G1 and S phases - In the S phase

In the S phase

A research team used a culture of lymphocytes with radioactively labeled T nucleotides to study the cell cycle. They found that the lymphocytes incorporated the labeled nucleotide at a significantly higher after a pathogen was introduced into the culture. Which of the following conclusions is most consistent with the results? - The pathogen consumed radiolabeled nucleotides. - Infection causes lymphocytes to divide more rapidly - Infection causes lymphocytes to increase in size - Infection causes lymphocyte cultures to skip some parts of the cell cycle

Infection causes lymphocytes to divide more rapidly

Besides the ability of some cancer cells to over-proliferate, which of the following situations is most likely to result in a tumor? - Changes in the order of cell cycle stages - Lack of appropriate cell death - Inability to form spindles - Failure of cells to enter S phase

Lack of appropriate cell death

The two homologs of a pair move toward opposite poles of dividing cell during ______. - Mitosis - Fertilization - Meiosis II - Meiosis I

Meiosis I

Which of the following events occurs during interphase of the cell cycle? - Spindle formation - Replication of the DNA - Separation of the spindle poles - Condensation of the chromosomes

Replication of the DNA

A triploid cell contains three sets of homologous chromosomes. Which of the following describes the chromosomes in a triploid cell where n-6? - The cell has 3 homologous pairs of chromosomes at the beginning of mitosis - The cell has 12 total chromosomes at the end of mitosis - The cell has 24 sister chromatids when in prophase I - The cell has 18 total chromosomes in 6 sets

The cell has 18 total chromosomes in 6 sets

Which of the following phrases defines the term genome? - The complete set of an organism's polypeptides - The complete set of an organism's genes and other DNA sequences - The complete set of a species' polypeptides - The complete set of a species expressed traits

The complete set of an organism's genes and other DNA sequences

Cells from a diploid protist with n=1 are followed through mitosis and meiosis. The drawings in the figure below represent the chromosomes. Refer to the drawings and answer the following question(s). Which diagram represents anaphase II of meiosis? - IV - I - III - V

V

The unlettered circle at the top of the accompanying figure shows a diploid nucleus with four chromosomes that have not yet replicated. The circles labeled 1 to 5 show various combinations of these chromosomes. Which chromosomal configuration would be observed in one daughter cell after telophase of mitosis? - II - IV - V - III

V

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 ______> - x - 0.25x - 2x - 0.5x

x