learning curve 11

Polar bodies are: produced by mitosis. haploid cells. functional gametes that are produced by mitosis. functional gametes.

haploid cells.

Another name for non-sister chromatids is: bivalents. chiasmata. diploids. homologous chromosomes.

homologous chromosomes.

What happens to CDK in the absence of cyclin? It is inactive and it becomes phosphorylated. It is inactive. It is degraded. It becomes phosphorylated.

inactive

Imagine that a researcher is studying a population of cells with two major phases. The first phase is relatively short (it lasts approximately one hour), whereas the second stage is much longer (lasting approximately 12 hours) and is characterized by an increase in the DNA content of cells. This second stage is most likely: interphase. G0. mitosis. cytokinesis.

interphase.

In which phase of mitosis do chromosomes line up at the middle of the cell? anaphase metaphase prophase telophase

metaphase

What cytoskeletal protein is important to the function of the sperm cells illustrated in Figure 11.13? microfilaments intermediate filaments microtubules All of these choices are correct.

mictrotubules

Crossing over occurs during which step in meiosis? prophase I anaphase I prophase II metaphase I

prophase I

Which of the following is not a step in the process of binary fission? DNA replicates formation of a new cell wall rearrangement of the microtubule cytoskeleton elongation of the cell

rearrangement of the microtubule cytoskeleton

Replication of DNA in a eukaryote occurs during which phase of the cell cycle? M phase G1 phase G2 phase S phase

s

When in the cell cycle would you find sister chromatids? G2 S G1 S and G2.

s and g2

What is the function of histone proteins? to organize DNA in eukaryotic chromosomes to connect chromosomes to the mitotic spindle to organize the microtubules that make up the spindle to attach sister chromatids together

to organize DNA in eukaryotic chromosomes

Evidence exists (especially in dinoflagellates) that mitosis actually evolved from binary fission. For example, in certain eukaryotic cells during mitosis, DNA is attached to the membrane of the nucleus (much like a circular chromosome of a bacterium is attached to the plasma membrane). true false

true

The alignment of chromosomes at metaphase of meiosis II is most similar to the alignment of chromosomes during metaphase of mitosis. true false

true

How many chromosome pairs are there in a human genome? 22 23 46 64

23

At the start of mitosis, how many centromeres are present in a human cell? 23 46 92 12

46

Why don't plant cells use a contractile ring to divide their daughter cells? Plant cells don't have an actin cytoskeleton. Plant cells don't form daughter cells. A contractile ring can't "pinch" a cell wall. Plant cells don't have plasma membranes.

A contractile ring can't "pinch" a cell wall.

Muscle cells are multinucleate, meaning that multiple nuclei are present in the cytoplasm of a large cell. Predict what is different about the cell cycle in a muscle cell. The G1 and G2 phases are extended. Cytokinesis does not occur. S phase happens twice. M phase is inhibited.

Cytokinesis does not occur.

What is the role of the protein FtsZ? It forms a ring at the site of constriction. It is involved in the attachment of DNA to the plasma membrane. It is responsible for the replication of DNA. It forms the new cell wall between daughter cells.

It forms a ring at the site of constriction.

The microtubules that form the mitotic spindle grow out from the centrosome. Where would you expect to find the plus (fast growing) end of a spindle microtubule? at the centrosome away from the centrosome at the kinetochore away from the centrosome, at the kinetochore

away from the centrosome, at the kinetochore

Why are the sex chromosomes not considered homologous? because they come from different parents because they do not carry the same collection of genes because males carry two very different chromosomes because they do not carry the same collection of genes, and because males carry two very different chromosomes

because they do not carry the same collection of genes, and because males carry two very different chromosomes

The process of cell division in a prokaryotic cell is called: binary fusion. mitosis. binary fission. cytokinesis.

binary fission.

How does meiosis generate genetic diversity? random alignment at metaphase I crossing over both crossing over and random alignment at metaphase I synapsis

both crossing over and random alignment at metaphase I

What cellular process(es) is/are responsible for the increase in protein content associated with the gap phases of the cell cycle? gene expression glycolysis protein synthesis both gene expression and protein synthesis

both gene expression and protein synthesis

A phragmoplast functions to: breakdown the nuclear envelope. anchor microtubules to sister chromatids. stimulate the growth of the microtubule spindle. form a new cell wall.

cell wall

The division of the cell's cytoplasm in a eukaryotic cell is known as: cytokinesis. cell fission. mitosis. cytokinesis and mitosis are both correct.

cytokinesis.

Which of the following statements is true regarding binary fission? Proteins only anchor the originalcircular genome to the plasma membrane; the copy produced by DNA replication is free-floating. In binary fission, cell division is typically asymmetrical, with one daughter cell appearing much smaller than the other. Tubulin, rather than FtsZ, is responsible for cell division during binary fission. DNA replication during binary fission is a bidirectionalprocess, occurring in opposite directions. None of the above answers are correct.

DNA replication during binary fission is a bidirectionalprocess, occurring in opposite directions.

A cell that is not actively dividing is in what phase of the cell cycle? G1 G0 G1' G null

G0

How does CDK promote cell division? It regulates the activity of cyclin. It binds to DNA. It phosphorylates other proteins. It changes the ability of microtubules to polymerize.

It phosphorylates other proteins.

Why would a compound that interferes with bacterial cell wall synthesis be useful for the treatment of an infection? It would prevent the cells from becoming larger. It would prevent replication of DNA. It would limit the spread of the infection. It would prevent replication of DNA, and it would limit the spread of the infection.

It would limit the spread of the infection.

Which checkpoint would become active if a chromosome was not properly aligned on the spindle? G1/S phase checkpoint G2/M phase checkpoint M phase checkpoint None of these choices are correct.

M phase checkpoint

Which of the following statements regarding tumor suppressors are true? Tumor suppressors promote cell division. Tumor suppressors act synergistically with proto-oncogenes. Mutations affecting tumor suppressors can contribute to the development of cancers. Tumor suppressors include PDGF and cyclins. None of the answer options are correct.

Mutations affecting tumor suppressors can contribute to the development of cancers.

A woman has her genome sequenced and finds that she carries a mutation in p53. Will she develop cancer? No, mutations in p53 do not contribute to cancer. Yes, she will certainly develop cancer given the role of p53 in the cell cycle. Possibly―this mutation may predispose her to developing certain types of cancer.

Possibly―this mutation may predispose her to developing certain types of cancer.

What would happen to the daughter cells if the G1 phase of the parent cell is shortened? The cells would be smaller than normal. The cells would be missing chromosomes. The cells would not undergo cytokinesis. The cells would be larger than normal.

The cells would be smaller than normal.

How do new cyclin proteins appear in the cytoplasm? They are recycled. They are made through protein synthesis. They are imported from outside the cell. All of these choices are correct.

They are made through protein synthesis.

In order for a malignant cancer to metastasize, it must: lose its connections to adjacent cells. lose its connections to the extracellular matrix. become motile. All of these choices are correct.

all

The prokaryotic protein FtsZ is evolutionarily related to eukaryotic tubulin. What does this mean? The gene sequence for FtsZ is similar to tubulin. The amino acid sequence for FtsZ is similar to tubulin. The overall protein structure of FtsZ is similar to tubulin. All of these choices are correct.

all

What properties are associated with a malignant cancer? It is fast growing. It invades surrounding tissue. It is metastatic. All of these choices are correct.

all

Which of the following statements regarding the cell cycle are true? It has three cell cycle checkpoints. It is regulated by cyclins and CDKs. Different levels of cyclins are observed at different cell cycle stages. It can be "paused" by the action of p53. All of the answer options are true.

all

In which phase of mitosis do microtubules shorten? metaphase anaphase prophase telophase

anaphase

At what step in meiosis do the daughter cells become haploid? prophase II anaphase II metaphase II anaphase I

anaphase I

A zygote is: haploid. monoploid. diploid. polyploid

diploid

Several years ago, a man noticed a small mole on his wrist. Years later, the mole grew in size and the man was diagnosed as having metastatic melanoma. This was likely the result of: a single mutation affecting one proto-oncogene in a cell. a single mutation inactivating a tumor suppressor. several mutations affecting proto-oncogenes and/or tumor suppressors. None of the answer options are correct―cancers arise spontaneously, independent of mutations.

several mutations affecting proto-oncogenes and/or tumor suppressors.

Synapsis is best described as: the exchange of genetic information between sister chromatids. the exchange of genetic information between non-sister chromatids. the alignment of homologous chromosomes in prophase I. the alignment of non-sister chromatids at the metaphase plate.

the alignment of homologous chromosomes in prophase I.

What do the colors in in the figure below likely represent? different levels of packaging and condensation of the chromatin. the presence of different histone proteins in the chromatin. the presence of different genes along the length of DNA. nothing, they are just there to make the chromosomes look nice.

the presence of different genes along the length of DNA.