chapter 12 cell cycle

Cells will usually divide if they receive the proper signal at a checkpoint in which phase of the cell cycle? cytokinesis M G2 G1 S

G1

At the M phase checkpoint, the complex allows for what to occur? At the M phase checkpoint, the complex allows for what to occur? All microtubules are made to bind to kinetochores. Cohesins alter separase to allow chromatids to separate. Separase enzyme cleaves cohesins and allows chromatids to separate. Daughter cells are allowed to pass into G1. Kinetochores are able to bind to spindle microtubules.

Separase enzyme cleaves cohesins and allows chromatids to separate.

Homologous chromosomes migrate to opposite poles during metaphase II telophase II and cytokinesis metaphase I prophase II anaphase I

anaphase I

During _____ sister chromatids separate. prophase I prophase II interphase anaphase II metaphase I

anaphase II

At which stage of mitosis are chromosomes usually photographed in the preparation of a karyotype metaphase anaphase prophase interphase

metaphase

At which stage of mitosis are chromosomes usually photographed in the preparation of a karyotype? anaphase metaphase interphase telophase prophase

metaphase

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

metaphase II

Asexual reproduction occurs during chromosome exchange between organisms of different species mitosis meiosis fertilization

mitosis

what process is going on in a human hand mitosis meiosis both none

mitosis

Sister chromatids separate from each other during meiosis I only mitosis and meiosis I meiosis II only mitosis and meiosis II

mitosis and meiosis II

A triploid cell contains three sets of chromosomes. If a cell of a usually diploid species with 42 chromosomes per cell is triploid, this cell would be expected to have which of the following? 63 chromosomes, each with three chromatids 63 chromosomes in 21 sets of 3 63 chromosomes in 31 1/2 pairs 21 chromosome pairs and 21 unique chromosomes

63 chromosomes in 21 sets of 3

If there are 20 centromeres in a cell at anaphase, how many chromosomes are there in each daughter cell following cytokinesis? 40 20 10 30 80

10

The beginning of anaphase is indicated by which of the following? Cohesin is cleaved enzymatically. Chromatids lose their kinetochores. Kinetochores attach to the metaphase plate. Cohesin attaches the sister chromatids to each other. Spindle microtubules begin to polymerize.

Cohesin is cleaved enzymatically

Which of the following is found in binary fission but not in mitosis? The result produces 2 nuclei. Following the process, a membrane separates the 2 copies. Replication of DNA begins at an origin. Replicated strands of DNA separate. Duplicated chromosomes attach to the plasma membrane.

Duplicated chromosomes attach to the plasma membrane.

Which of the following correctly matches a phase of the cell cycle with its description? G1: follows cell division G2: cell division M: duplication of DNA S: immediately precedes cell division All of the above are correctly matched.

G1: follows cell division

Which of the following are primarily responsible for cytokinesis in plant cells but not in animal cells? kinetochores actin and myosin centrioles and centromeres Golgi-derived vesicles

Golgi-derived vesicles

How are sister chromatids and homologous chromosomes different from each other? They are not different. Homologous chromosomes and sister chromatids are both identical copies of each other. Homologous chromosomes are closely associated with each other in both mitosis and meiosis. Sister chromatids are only associated with each other during mitosis. Homologous chromosomes are identical copies of each other. One sister chromatid comes from the father, and one comes from the mother. Sister chromatids are only formed during mitosis. Homologous chromosomes are formed during meiosis. 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.

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.

For the following question, match the key event of meiosis with the stages listed below. 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. VI II IV I

II

For what purpose(s) might a karyotype be prepared? Choose the best answer. for prenatal screening, to determine if a fetus has the correct number of chromosomes to determine whether a fetus is male or female to detect the possible presence of chromosomal abnormalities such as deletions, inversions, or translocations The first and second answers are correct. The first three answers are correct.

The first three answers are correct.

For the following question, match the key event of meiosis with the stages listed below. 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. III IV V VII

VII

For the following question, match the key event of meiosis with the stages listed below. I. Prophase I V. Prophase IIII. 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.

VII

Metaphase is characterized by aligning of chromosomes on the equator splitting of the centromeres cytokinesis separation of sister chromatids

aligning of chromosomes on the equator

Cyclin-dependent kinase (Cdk) is present only during the S phase of the cell cycle inactive, or "turned off," in the presence of cyclin the enzyme that catalyzes the attachment of chromosomes to microtubules an enzyme that attaches phosphate groups to other proteins

an enzyme that attaches phosphate groups to other proteins

The drug cytochalasin B blocks the function of actin. Which of the following aspects of the cell cycle would be most disrupted by cytochalasin B? spindle attachment to kinetochores spindle formation cell elongation during anaphase cleavage furrow formation and cytokinesis

cleavage furrow formation and cytokinesis

One difference between cancer cells and normal cells is that cancer cells are arrested at the S phase of the cell cycle. are always in the M phase of the cell cycle. continue to divide even when they are tightly packed together. cannot function properly because they are affected by density-dependent inhibition. are unable to synthesize DNA.

continue to divide even when they are tightly packed together

Kinetochore microtubules assist in the process of splitting centromeres by creating tension by pulling toward opposite poles sliding past each other like actin filaments using motor proteins to split the centromere at specific arginine residues phosphorylating the centromere, thereby changing its conformation

creating tension by pulling toward opposite poles

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

four ... haploid

A cleavage furrow is a ring of vesicles forming a cell plate the separation of divided prokaryotes a groove in the plasma membrane between daughter nuclei the space that is created between two chromatids during anaphase

groove in the plasma membrane between daughter nuclei

After telophase I of meiosis, the chromosomal makeup of each daughter cell is tetraploid, and the chromosomes are each composed of two chromatids. haploid, and the chromosomes are each composed of a single chromatid. haploid, and the chromosomes are each composed of two chromatids. diploid, and the chromosomes are each composed of a single chromatid. diploid, and the chromosomes are each composed of two chromatids

haploid, and the chromosomes are each composed of two chromatids.

The human X and Y chromosomes are called autosomes are the same size and have the same number of genes are both present in every somatic cell of males and females include genes that determine an individual's sex

include genes that determine an individual's sex

At which phase are centrioles beginning to move apart in animal cells? At which phase are centrioles beginning to move apart in animal cells? prophase anaphase metaphase prometaphase

prophase

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

prophase I

When we first see chiasmata under a microscope, we know that separation of homologs has occurred meiosis II has occurred prophase I is occurring anaphase II has occurred

prophase I is occurring

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

prophase II

Which of the following does not occur during mitosis? replication of the DNA separation of sister chromatids condensation of the chromosomes separation of the spindle poles spindle formation

replication of the DNA

Movement of the chromosomes during anaphase would be most affected by a drug that prevents shortening of microtubules nuclear envelope breakdown formation of a cleavage furrow elongation of microtubules

shortening of microtubules

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

sister chromatids separate during anaphase.

Which of the following occurs in meiosis but not in mitosis synapsis of chromosomes alignment of chromosomes at the equator chromosome replication condensation of chromosomes

synapsis of chromosomes

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

telophase I

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

telophase II

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

two ... haploid