Chapter 11 Learning Curve

What would happen if a chromosome only connected to the mitotic spindle at one of its kinetochores?

-One of the daughter cells would have an extra copy of that chromosome. -The sister chromatids would not separate. -The chromosome would not line up properly at metaphase.

What properties are associated with a malignant cancer?

-It is fast growing. -It invades surrounding tissue. -It is metastatic.

How would the loss of p53 activity affect a cell?

-The G1/S checkpoint would not be functional. -DNA damage could accumulate. -CDK activity would not be appropriately regulated.

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. -The two proteins evolved from a common ancestral protein.

Cell cycle checkpoints:

-act as a brake on cell division if something is not right. -provide opportunities to check if the cell has carried out steps necessary for cell division. -can involve the protein p53.

Asexual reproduction occurs in:

-unicellular eukaryotes. -animal cells. -plant cells. -bacterial cells.

How many chromosome pairs are there in a normal human genome?

23

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

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

A graduate student is planning an experiment to evaluate the expression of PDGF-related genes in her cell population of interest. As a control, she hopes to confirm the expression of genes that are present in all dividing cells. For her controls, she should evaluate the expression of:

CDKs

Muscle cells in the mammalian heart 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.

Cytokinesis does not occur.

Which of the following statements is true regarding binary fission?

DNA replication during binary fission is a bidirectional process, occurring 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.

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

G0

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

It would limit the spread of the infection through cell division.

What would happen if crossing over occurred between sister chromatids?

Nothing would happen because sister chromatids are genetically identical or nearly identical.

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.

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

The cells would be smaller than normal

What is a cyclin?

a protein that activates kinases and a protein whose levels change with the cell cycle

A gene associated with promoting normal cell division is called:

a proto-oncogene.

What type of protein is being activated by the G1/S cyclin-CDK complex to promote the expression of histone proteins?

a transcription factor

What protein forms the contractile ring during cytokinesis in animal cells?

actin

In which phase of mitosis do sister chromatids separate?

anaphase

In which phase of mitosis do spindle microtubules shorten?

anaphase

During what step in meiosis do the daughter cells become haploid?

anaphase 1

When do sister chromatids separate in meiosis?

anaphase II

How does meiosis generate genetic diversity?

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?

both gene expression and protein synthesis

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

cytokinesis.

A zygote is:

diploid

All cancers are caused by viruses.

false

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 (it lasts approximately 12 hours) and is characterized by an increase in the DNA content of cells. This second stage is most likely:

interphase.

Homologous chromosomes separate from each other in:

meiosis 1

What cytoskeletal protein is important to the function of the sperm cells illustrated in Figure 11.13?

microtubules

In which phase of mitosis do chromosomes condense?

prophase

Which of the following is not a step in the process of binary fission?

rearrangement of the microtubule cytoskeleton

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:

several mutations affecting proto-oncogenes and/or tumor suppressor genes.

In which phase of mitosis does the nuclear envelope reform?

telophase

Mitotic cell division is considered asexual because:

the daughter cells receive DNA from one parent cell, and the daughter cells are genetically identical.

What is the function of the centromere?

to attach the sister chromatids to each other

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

true