Biology 114- Chapter 14 LearnSmart

Carcinoma

A _____ is a cancer of epithelial cells.

Translocation

A genetic alteration called a chromosomal _____ occurs when one segment of a chromosome becomes attached to a different chromosome.

Proto

A missense mutation in a(n) _____-oncogene can convert it to a cancer-promoting gene if the mutation alters the function of the encoded protein to allow for increased cell division.

50

A mutation in a germline cell has a(n) _____ percent chance of being transmitted from parent to child

1. Proto 2. Oncogene

A normal gene that can become an oncogene if it is mutated is called a(n) (1)_____-(2)_____.

Point

A(n) _____ mutation affects only a single base pair

50

About _____% of human cancers are associated with mutation of the p53 gene.

1. Germ-line cells 2. Somatic Cells

Animal cells are classified into two main types. Which ones?

Programmed cell death

Apoptosis is a term that refers to:

1. The UvrA-UvrB complex identifies a damaged site 2. UvrC makes cuts on both sides of the damaged site 3. UvrD binds and removed the damaged region 4. DNA polymerase synthesizes new DNA to fill the gap 5. DNA ligase seals the newly synthesized DNA to the original strand

Arrange the events that occur in nucleotide excision repair in E. coli in the correct order

1. Germ 2. Line

Cells that give rise to gametes, such as egg and sperm cells, are known as the (1)_____ (2)_____ cells.

By creating an abnormal gene that encodes a fusion protein

How can a chromosomal translocation cause cancer?

By generating too much of the encoded protein

How can gene amplification of a proto-oncogene cause cancer?

1. By substituting one base for another 2. By adding or subtracting a single base pair

How do point mutations affect DNA sequences? (Check ALL that apply)

They are highly sensitive to the sun

How does Xeroderma pigmentosum (XP) affect individuals that have inherited this disorder?

It hydrolyzed GTP to GDP

How does the Ras protein return to an inactive state?

The protein encoded by the oncogene is unable to hydrolyze GTP

How does the protein encoded by the ras oncogene differ from the protein encoded by the normal ras gene?

Apoptosis

If DNA damage is too severe, the p53 protein will activate genes that promote _____.

1. Gamete-producing precursors 2. Sperm 3. Egg

In what types of cells do germ line mutations occur?

Tumor-suppressor genes

Maintenance of genome integrity and negative regulation of cell division are the two main functions of:

1. Proto 2. Oncogene

On occasion, a retrovirus may insert its DNA into a host chromosome near a(n) (1)_____-(2)_____. This may result in the overexpression of this type of gene, thereby promoting cancer

300

Researchers have estimated that about _____ genes may play a role in the development of human cancer

Checkpoint

Some tumor-suppressor genes encode proteins that test the integrity of the genome and prevent a cell from progressing past a certain stage in the cell cycle. These proteins are termed _____ proteins.

Somatic

Sperm and egg cells are termed germ line cells. In contrast, cells of the skin, muscle, heart, and liver are examples of _____ cells.

Cancer

The Rous sarcoma virus is an example of a virus that causes:

Methylated

The expression of a tumor-suppressor gene may be reduced when CpG islands near its promoter region are ______.

1. 5'-AACCCGTT-3'---Base substitution 2. 5'-AACCCGGTT-3'---Single base addition 3. 5'-AACGGTT-3'---Single base deletion

The original sequence of a DNA molecule is 5'-AACCGGTT-3'. Match each mutated sequence with the correct description of the change that occurred.

Activating genes that encode proteins that stop the cell cycle

The p53 protein can arrest the cell cycle at the G1 stage by:

DNA

The p53 protein is encoded by a tumor-suppressor gene which is expressed when _____ is damaged.

Metastasis

The process that occurs when cancer cells spread into the blood and other parts of the body is known as _____.

Tumor-suppressor gene

The protein p53 is encoded by a(n):

p53

The protein product of what tumor-suppressor gene acts to sense DNA damage, promote DNA repair, and halt cell division?

False

True or false: Cancer usually requires only one or two genetic changes to the small cell lineage

True

True or false: The earlier in development a somatic mutation occurs, the larger the patch of tissue that will be affected by that mutation.

False

True or false: The function of a normal tumor-suppressor gene is to promote cell division

All cells of the body that are not germ line cells

What are somatic cells?

1. Mutation within the gene 2. Abnormal DNA methylation near the gene's promoter 3. Loss of the chromosome that carries the gene

What are the three most common ways that the function of a tumor-suppressor gene is lost? (Check ALL that apply)

1. Cyclins 2. Cyclin-dependent kinases

What are the two types of proteins that are responsible for advancing a cell through the phases of the cell cycle? (Check ALL that apply)

1. Transcription factor 2. Growth factor receptor 3. Intracellular signaling protein

What are the typical functions of proteins encoded by genes that may become oncogenes? (Check ALL that apply)

The sequence of bases in a particular gene

What does a gene mutation affect

A mutation that occurs when one base is replaced by another

What is a base substitution?

An individual with somatic regions that are genetically different from each other

What is a mosaic?

An increase in the number of copies of a gene

What is gene amplification

1. It may carry an oncogene in its genome 2. It may insert their DNA near proto-oncogenes

What two mechanisms enable a retrovirus to promote cancer?

Nonsense

What type of mutation changes a normal codon to a termination codon?

Silent

What type of mutation has no effect on the amino acid sequence of a polypeptide?

Frameshift

What type of mutation is the result of the insertion or removal of nucleotides that does not occur in multiples of three?

Connective tissue

What type of tissue is a sarcoma derived from?

The coding region of a structural gene

Where must a mutation occur if it is to directly affect an amino acid sequence?

Overactive

Where oncogenes are ______ compared to proto-oncogenes, they can promote certain types of cancer

1. A nucleotide is removed from a gene 2. The base sequence within the gene is changed 3. A nucleotide added to a gene

Which of the following are ways that point mutations may alter a gene? (Check ALL that apply)

It is a tumor-suppressor gene involved in the negative regulation of cell division

Which of the following best describes the retinoblastoma (Rb) gene?

ras

Which of the following genes is an oncogene?

1. Missense Mutations 2. Gene Amplifications 3. Chromosomal Translocations 4. Retroviral insertions

Which of the following genetic changes can convert a proto-oncogene into an oncogene? (Check ALL that apply)

Cancer involves a series of mutations that take time to accumulate in a cell lineage

Why does cancer affect people more as they age?

DNA repair

Xeroderma pigmentosum and Cockayne syndrome are genetic disease that affect:

Repair UV-induced lesions

Xeroderma pigmentosum causes a predisposition to skin cancer because it impairs the ability to

Caspases

_____ are enzymes that are activated during programmed cell death to digest certain cellular proteins such as actin filaments.