Week 10 Review Questions

Cell division is regulated by: signals about the nutritional status of the cell. signals that indicate that the cell has reached a sufficient size. growth factor signals. All of these choices are correct. signals that indicate that DNA has been replicated.

All of these choices are correct.

Which of the following statements concerning cyclin-dependent kinases (CDKs) is NOT true? CDKs are present throughout the cell cycle. CDKs are inactive, or "turned off," in the presence of cyclins. CDKs are enzymes that attach phosphate groups to other proteins. CDKs are active, or "turned on," when complexed with cyclins. Instructional Guidance: This question is tied to How Do We Know Figure 11.15.

CDKs are inactive, or "turned off," in the presence of cyclins.

_____ is the process where new genes evolve from duplicates of old ones. Reciprocal translocation Deletion Centromere dosage Inversion Duplication and divergence

Duplication and divergence

Look carefully at the image of the human karyotype shown in Figure 11.3. What is the significance of the small differences between homologous chromosomes? The differences are a result of the way the material was prepared. Some of this person's DNA is mutated, possibly causing disease. Chromosomes may not be completely replicated during S phase. Each homologous chromosome in a pair is from a different parent.

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

Any DNA "damage" is considered to be a mutation, even if it is immediately corrected by the action of DNA polymerase. True False

False

What is the difference between mismatch repair and nucleotide excision repair? In mismatch repair, several nucleotides are replaced, whereas in nucleotide excision repair it is just one. In mismatch repair, the sugar phosphate backbone is fixed, whereas in nucleotide excision repair, several nucleotides are replaced. In mismatch repair, one nucleotide is replaced, whereas in nucleotide excision repair several nucleotides are replaced. In mismatch repair, several nucleotides are replaced, whereas in nucleotide excision repair the sugar phosphate backbone is fixed.

In mismatch repair, one nucleotide is replaced, whereas in nucleotide excision repair several nucleotides are replaced.

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

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

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

S and G2

_____ mutations affect only the individual in which they occur; _____ mutations are passed from parent to offspring. Germ-line; heritable Somatic; germ-line Germ-line; somatic Somatic; point Point; germ-line

Somatic; germ-line

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

They are made through protein synthesis.

A chromosomal mutation in which a segment is missing is called a deletion. False True

True

Insertion of one nucleotide in a gene will lead to a frameshift mutation. True False

True

Mutagens increase the amount of damage to DNA. True False

True

Which of the following statements concerning cancer and mutations is CORRECT? Usually, a single mutation is all that is required to cause cancer. None of the other answer options is correct. Cancer can only occur with a mutation in a somatic cell. Usually, multiple mutations are required in different genes to cause cancer. Cancer can only occur with a mutation in a germ cell.

Usually, multiple mutations are required in different genes to cause cancer.

Which of the following causes breaks in one or both of the sugar-phosphate backbones? UV radiation exposure to oxidizing agents such as household bleach or hydrogen peroxide tobacco smoke X-rays

X-rays

What is a cyclin? a kinase a protein whose levels change with the cell cycle a protein that activates kinases and a protein whose levels change with the cell cycle a protein that activates kinases

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

The development of cancer requires both the _____ of an oncogene and the _____ of a tumor suppressor. activation; activation inhibition; activation inhibition; inhibition activation; inhibition

activation; inhibition

CDKs are important in the regulation of the cell cycle. They carry out their function by: preventing the progression of a cell from one stage of the cell cycle to the next. removing phosphate groups from target proteins. adding phosphate groups to target proteins. degrading cyclin proteins.

adding phosphate groups to target proteins.

In which phase of mitosis do sister chromatids separate? prophase metaphase telophase anaphase

anaphase

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

anaphase

When a transposable element inserts into a gene, it can: (Select all that apply.) cause the gene to delete itself. interfere with transcription. cause errors in RNA processing. disrupt the open reading frame. cause the gene to duplicate itself.

interfere with transcription. cause errors in RNA processing. disrupt the open reading frame.

A chromosomal mutation where a segment breaks off, flips, and then reattaches itself is called a(n): reciprocal translocation. deletion. translocation. inversion. duplication.

inversion

A malignant cancer differs from a benign cancer in that: malignant cancers invade surrounding tissue and benign cancers do not. benign cancers are lethal and malignant ones are not. malignant cancers are lethal and benign cancers are not. malignant cancers are caused by viruses and benign cancers are not.

malignant cancers invade surrounding tissue and benign cancers do not.

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

metaphase

Which type of repair is a backup for the DNA polymerase proofreading function? nucleotide excision repair mismatch repair base excision repair DNA ligase

mismatch repair

The definition of mutation is "any heritable change in the genetic material." The qualifier "heritable" is necessary because: changes in the genetic material occur without regard to the needs of the organism. most changes in the genetic material are harmful to the organism. changes in the genetic material occur at random along the genome. most changes in the genetic material are repaired soon after they occur.

most changes in the genetic material are repaired soon after they occur.

The relatively large number of new mutations that occur in the human genome in each generation is tolerable because: most of our genome is noncoding DNA, so few mutations affect our proteins. most of the mutations occur in somatic cells, not germ cells. we have excellent protein repair mechanisms. we have excellent DNA repair mechanisms. compared to other organisms, changes in our proteins have relatively little effect on our cells' structures and functions.

most of our genome is noncoding DNA, so few mutations affect our proteins.

In organisms with large genomes, inversions are more likely to be tolerated if the breakpoints occur in: reciprocal translocations. coding DNA. closed reading frames. noncoding DNA. open reading frames.

noncoding DNA

Point mutations that cause amino acid replacements are called: stop mutation. transition mutation. nonsynonymous (missense) mutation. nonsense mutation. synonymous (silent) mutation.

nonsynonymous (missense) mutation.

In which phase of mitosis do chromosomes condense? metaphase prophase telophase anaphase

prophase

A gene associated with promoting normal cell division is called a(n): proto-oncogene. oncogene. tumor suppressor. proto-oncogene or a tumor suppressor.

proto-oncogene

Chronic myelogenous leukemia (CML) is caused when a segment of chromosome 9 and a segment of chromosome 22 both break off and switch places. How is this mutation classified? inversion transposition deletion reciprocal translocation duplication

reciprocal translocation

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 inactivating a tumor suppressor gene. several mutations affecting proto-oncogenes and/or tumor suppressor genes. a single mutation affecting one proto-oncogene in a cell. None of the other answer options is correctcancers arise spontaneously, independent of mutations.

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

The two molecules of double-stranded DNA in a replicated chromosome are called: non-sister chromatids homologous chromosomes bivalent chromosomes sister chromatids

sister chromatids

A point mutation that causes no change in the amino acid sequence of a protein is called a: nonsynonymous (missense) mutation. nonsense mutation. synonymous (silent) mutation. transition mutation. stop mutation.

synonymous (silent) mutation.

In which phase of mitosis does the nuclear envelope reform? anaphase metaphase telophase prophase

telophase

A chromosomal segment that breaks off and attaches to another chromosome is what type of mutation? reciprocal translocation duplication deletion inversion translocation

translocation

Mismatch repair, base excision repair, and nucleotide excision repair are similar in that each: (Select all that apply.) repairs a short strand of mismatched nucleotides. repairs a single mismatched base. repairs multiple mismatched or damaged bases across a region. None of the answer options is correct. uses an undamaged segment of DNA as the template to repair a damaged segment of DNA.

uses an undamaged segment of DNA as the template to repair a damaged segment of DNA.