Chapter 8: DNA Replication, Binary Fission, and Mitosis

Shortly after fertilization, a zygote divides into two identical cells. What type of cell division produces these two cells?

A. mitotic cell division

B. meiotic cell division

C. apoptosis

A. mitotic cell division

Why is binary fission an asexual process?

A. It occurs only in prokaryotes.

B. It does not require DNA replication.

C. It produces two identical cells.

D. The chromosome is circular.

C. It produces two identical cells.

In some fungi and slime molds, mitosis may occur without cytokinesis. What would you expect to find in these species?

A. Cells that don't contain nuclei.

B. Cells that contain multiple nuclei.

C. DNA that never condenses into visible chromosomes.

D. Nuclei that never enter interphase.

B. Cells that contain multiple nuclei.

A DNA molecule is placed in a test tube containing fluorescently tagged nucleotides. DNA replication is induced. After replication,

A. only one DNA molecule would have two fluorescent strands.

B. both strands of each DNA molecule would be half-fluorescent.

C. each DNA molecule would have one florescent strand.

D. both DNA molecules would be completely fluorescent.

C. each DNA molecule would have one florescent strand.

Which of the following best explains why binary fission can occur without a spindle like that found in mitotic cells?

A. The cell is small, so there is less material to divide.

B. There is only one chromosome, and it attaches to the membrane.

C. The prokaryotic DNA does not need to replicate. D. Prokaryotic cells lack chromosomes, so the spindle is unnecessary

B. There is only one chromosome, and it attaches to the membrane.

Which stage of the cell cycle occurs immediately after the stage in which the chromosomes become visible?

A. Anaphase

B. Prophase

C. Prometaphase

D. Telophase

C. Prometaphase

Imagine that gene X mutates and begins encoding a protein that accelerates the cell cycle. Before it mutated, gene X was most likely a(n)

A. proto-oncogene.

B. oncogene.

C. tumor suppressor gene.

D. apoptosis gene

A. proto-oncogene.

What is the role of the executioner protein in apoptosis?

A. They kill the cell by destroying its proteins.

B. They function as the "death receptors" on the surface of the cell.

C. They are part of the immune response that eliminates the cells.

D. They cause the cell to swell and burst.

A. They kill the cell by destroying its proteins.

In which stage does DNA replication take place?

A. Interphase

B. Prophase

C. Metaphase

D. Cytokinesis

A. Interphase

In which stage do the spindle fibers move the chromosomes and alight the down the center of the cell?

A. Prophase

B. Metaphase

C. Anaphase

D. Telophase

B. Metaphase

Upon completion of the cell cycle, each daughter will _____________.

A. contain half the genetic information of the parent cell

B. contain double the genetic information of the parent cell

C. be genetically identical to the parent cell

C. be genetically identical to the parent cell

A chromosome is made of

A. DNA.

B. histones.

C. chromatin.

D. all of the above.

D. all of the above.

Why is a chromosome composed of two chromatids?

A. Because the nucleosomes are folded.

B. Because the chromosome contains the entire genome of a cell.

C. Because the DNA has replicated.

D. Because the cell is diploid.

C. Because the DNA has replicated.

A ______ cell is ______ and a gamete is ______

A. sperm; diploid; haploid.

B. somatic; diploid; haploid.

C. germ; haploid; diploid.

D. somatic; haploid; diploid.

B. somatic; diploid; haploid.

How is G0 different from G1?

A. In G0 the cell is replicating its DNA.

B. A G1 cell is getting ready to divide, but a G0 cell has already divided.

C. G0 occurs at the end of interphase.

D. A G1 cell can continue to divide, but a G0 cell does not.

D. A G1 cell can continue to divide, but a G0 cell does not.

Which is the correct order of phases in mitosis?

A. prometaphase, prophase, metaphase, anaphase, telophase

B. prometaphase, metaphase, telophase, anaphase, prophase

C. prophase, prometaphase, metaphase, anaphase, telophase

D. telophase, anaphase, metaphase, prometaphase, prophase

C. prophase, prometaphase, metaphase, anaphase, telophase

What would happen to a dividing animal cell if there was no cytokinesis?

A. The number of nuclei in the cell would increase over time.

B. The amount of DNA in the cell would decrease over time.

C. The cell would enter G0.

D. The cell would not form a new cell wall.

A. The number of nuclei in the cell would increase over time.

Why is the metaphase checkpoint so important?

A. Because it determines how quickly a cell goes through mitosis.

B. Because it ensures that the chromosomes will be properly separated.

C. Because it ensures that cytokinesis will proceed properly.

D. Because it can trigger apoptosis.

B. Because it ensures that the chromosomes will be properly separated.

Predict how excess telomerase activity would affect a cell.

A. It would cause the telomeres of the chromosomes to rapidly shrink.

B. It would reduce the number of chromosomes in the cell.

C. It would increase the number of times the cell could divide.

D. It would inhibit growth of the organism.

C. It would increase the number of times the cell could divide.

What is an oncogene?

A. A gene that normally regulates the cell cycle

B. A gene that regulates cell death

C. An abnormal allele of a gene that can influence the cell cycle

D. A gene that responds to the signals associated with contact inhibition

C. An abnormal allele of a gene that can influence the cell cycle

Why are the caspases so important to apoptosis?

A. They kill the cell by destroying its DNA and proteins.

B. They function as the "death receptor" on the surface of the cell.

C. They are part of the immune response that eliminates the cells.

D. They cause the cell to swell and burst.

A. They kill the cell by destroying its DNA and proteins.

An egg from a Venezuelan gecko has a very low number of 16 chromosomes. Thus, the entire ________ consists of 32 chromosomes, and each chromosome consists of __________ and proteins.

A. DNA; chromatin

B. genome; nucleosomes

C. chromatin; genome

D. nucleosomes; centromere

E. genome; DNA

E. genome; DNA

Somatic cells in a goldfish have 94 chromosomes. Thus, an egg produced by a female would be __________ and have ____ chromosomes.

A. haploid; 47

B. diploid; 47

C. a gamete; 94

D. a germ cell; 94

E. diploid; 94

A. haploid; 47

Which of the following occur during interphase?

A. cytokinesis

B. separation of sister chromatids

C. cells carried out basic functions

D. DNA starts to condense

C. cells carried out basic functions

A mutation in gene coding for the p53 protein that prevents the protein from functioning could result in which of the following?

A. Growth and replication of damaged cells.

B. Apoptosis.

C. Growth of cells with repaired DNA.

D. Normal cells will undergo additional mutations.

A. Growth and replication of damaged cells.

In a skin cell, long telomeres indicate that the cell has undergone ____________ divisions.

A. many

B. few

C. 50

D. Impossible to tell from the information given

B. few

After a visit to a specialist, Dan was diagnosed with liver cancer. Six months later additional tumors were found in his stomach and small intestine. This is an example of _____________.

A. oncogenes

B. contact inhibition

C. benign tumors

D. metastasis

D. metastasis

A gene that codes for a receptor for a growth factor is mutated. A normally functioning receptor binds with a growth factor and then sends a signal into the cell. However, the abnormal receptor sends a constant signal into the cell whether or not it binds with a growth factor. The gene that codes for the abnormal receptor is ____________.

A. an oncogene

B. a tumor

C. malignant

D. a tumor suppressor gene

E. metastatic

A. an oncogene

Webbing of the digits (fingers) in humans, or syndactyly, typically occurs during the sixth to eighth weeks of embryonic life. It occurs in one of every 2000 to 2500 births and is more common among Caucasian males. Syndactyly is caused by the failure of what process?

A. cell division

B. mitosis

C. cytokinesis

D. tumor suppression

E. apoptosis

E. apoptosis

Endostatin is a drug that _____________.

A. has many side effects

B. is an angiogenesis inhibitor

C. promotes growth of new blood vessels

D. is very effective in all humans

E. All of the above are true about endostatin.

B. is an angiogenesis inhibitor