Biol chapter 11 learning curve

A human cell with a total of 23 chromosomes is:

haploid

What happens to CDKs in the absence of cyclins?

they are inactive

What would happen to the daughter cells if the G2 phase of the parent cell is shortened?

The cells would be smaller than normal.

Why are the X and Y chromosomes not considered homologous?

They do not carry the same set of genes.

What is the function of histone proteins?

to package/organize DNA in eukaryotic chromosomes

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

transcription and translation

An example of second-division nondisjunction is when sister chromatids fail to separate during anaphase of meiotic cell division. t/f

true

Evidence exists (especially in dinoflagellates) that mitosis 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). t/f

true

Some types of leukemia are the result of constitutively active (that is, "always on") growth factor receptors. t/f

true

The process of cell division in a prokaryotic cell is called:

binary fission.

The division of the cell's cytoplasm in a eukaryotic cell is known as:

cytokinesis.

The assembly of what cytoskeletal structures are initiated by the M cyclin-CDK complex?

microtubules

The division of genetic material in a eukaryotic cell is called:

mitosis.

In which phase of mitosis does the mitotic spindle form?

prophase

What type of gene is c-src (cellular-src)?

proto-oncogene

There are no discernible phenotypic effects for an individual with the genotype XYY. t f

t

How would the loss of p53 activity affect a cell?

-DNA damage could accumulate. -The G1/S checkpoint would be unregulated. -CDK activity would be altered.

What is the role of the protein FtsZ in prokaryotes?

It forms a ring at the site of constriction.

A couple has a baby that only has one X chromosome and no Y chromosome. This could have occurred because: All of these choices are correct. there was nondisjunction of homologous chromosomes in meiosis I in the mother. Meiosis in the father was normal. there was nondisjunction of the sister chromatids in meiosis II in the mother. Meiosis in the father was normal. there was nondisjunction of sister chromatids in meiosis II of the father. Meiosis in the mother was normal. there was nondisjunction of the paired X and Y chromosomes in meiosis I in the father. Meiosis in the mother was normal.

All of these choices are correct.

Muscle cells in the mammalian heart are multinucleate, meaning that multiple nuclei are present in the cytoplasm of individual large cells. Predict what is different about the cell cycle in a muscle cell.

Cytokinesis does not occur.

Which statement is true regarding binary fission?

DNA replication of the circular bacterial chromosome during binary fission is a bidirectional process, starting at one point but progressing in opposite directions.

Predict what would happen if crossing over between homologous chromosomes occurred as part of mitosis.

Daughter cells would not be genetically identical, and they could contain two copies of the same allele.

If you analyze the sequences of the two copies of any of the chromosomes shown in the karyotype, there would be slight sequence differences. What could account for the small differences between a few of the homologous chromosomes? Click to view full size.

Each homologous chromosome in a pair is from a different parent.

A cell that is not actively dividing is in what phase of the cell cycle?

G0

At the start of mitosis, how many sister chromatids are present in a human cell?

46

Why don't plant cells use a contractile ring to divide their daughter cells?

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

Sexual reproduction results in an increase in genetic diversity because: during prophase I, genes that are paternally and maternally derived recombine so that the gametes have chromosomes that are different from the parents' chromosomes. All of these choices are correct. during metaphase I, the bivalents line up in a random orientation so that gametes inherit a random set of maternally and paternally derived chromosomes. during fertilization, the gametes that fuse are random so that a large number of chromosomal combinations are possible in the new organism.

All of these choices are correct.

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

All of these choices are correct.

What would happen if a pair of sister chromatids only connected to the mitotic spindle at one of their kinetochores? All of these choices are correct. The sister chromatids would not separate. The chromosome would not line up properly at metaphase. One of the daughter cells would have an extra copy of that chromosome.

All of these choices are correct.

Which cellular conditions promote progression of the cell cycle? All of these choices are correct. the accumulation of cyclins binding of cyclins to CDKs the activation of CDKs the expression and synthesis of cyclin proteins

All of these choices are correct.

Which statement regarding cancer, according to Douglas Hanahan and Robert Weinberg, are true? All of these choices are correct. Cancer cells can sometimes metastasize and travel throughout the body. Mutations in growth factor receptors are sometimes required for cancer cell division. Cancer cells can resist cell-death signals. Cancer cells typically secrete factors that promote blood vessel formation.

All of these choices are correct.

Which of the following is a characteristic of meiotic cell division?

Cell division results in the production of gametes.

Why would a compound that interferes with bacterial cell wall synthesis be useful for treating a bacterial infection?

It would limit growth of the bacterial population through cell division.

At which stage of the cell cycle could you see sister chromatids with a microscope?

M

Would genetic recombination result if crossing over occurred between sister chromatids?

No, because sister chromatids are genetically identical or nearly identical.

Which of the following is an accurate statement that accounts for why women with the genotype XXX are not phenotypically different from an XX female?

Only one X chromosome is active in each cell, regardless of how many X chromosomes there are in a cell.

A woman has her genome sequenced and finds that she carries a mutation in p53. Will she develop cancer?

Possibly; this mutation is likely to predispose her to developing certain types of cancer.

How must spindle microtubules attach to chromosomes during prometaphase of meiosis I?

Spindle microtubules from one pole must attach to both kinetochores in a pair of sister chromatids.