Chapter 11-Questions

A(n) _____________ is a protein that promotes cell division. In excess, such a protein may lead to cancer.

growth factor

Which gene would you expect to be active in a nerve cell?

Gene for glycolysis enzyme

All your cells contain proto-oncogenes, which can change into cancer-causing genes. Why do cells possess such potential time bombs?

Proto-oncogenes are necessary for normal control of cell division.

Why might researchers want to transplant tumor cells from human cancer patients into mouse avatars?

It is possible to determine appropriate drug treatments by screening different drugs in different mouse avatars.

The operon model of the regulation of gene expression in bacteria was proposed by _____.

Jacob and Monod

What is the function of a spliceosome?

RNA processing

Select all of the correct statements about transcription factors.

Transcription factors can switch genes off. Transcription factors can switch genes on.

You are observing a colony of fruit flies and notice one genetic line stops making wings. This is probably due to a mutation in ________.

a homeotic gene

Which of these is NOT a carcinogen?

all of the above are carcinogens (cigarette smoke, fat, UV light, testosterone)

Most mutagens are carcinogens. This is because __________.

both bring about cancer-causing DNA changes

In the absence of lactose, this mutant cell will _____ the enzyme for lactose metabolism. This mutation is ____ for the cell in terms for genetic use.

continuously produce, disadvantages

Although all of the cells in your body contain a complete set of DNA, different cells have different functions because __________.

different genes are switched on and off in each type of cell

_____ is a carcinogen that promotes colon cancer.

fat

What kinds of somatic cell gene mutations can frequently lead to the first stages of cancer?

mutations in genes that regulate cell division

Which of the following would be most likely to lead to cancer?

mutations in proto-oncogenes and inactivation of a tumor-suppressor gene

In the presence of a regulatory protein the lac operon is _____.

not transcribed

A gene that causes a cell to become cancerous is called a(n) ________

oncogene

Enzyme complexes that break down protein are called _____.

proteasomes

Protein-phosphorylating enzymes' role in the regulation of gene expression involves _____.

protein activation

A normal gene that, if mutated, can lead to cancer is called a(n) ________

proto-oncogene

The nuclear membrane's role in the regulation of gene expression involves _____.

regulating the transport of mRNA to the cytoplasm

Which of these is NOT a component of the lac operon?

regulatory gene only

Regulatory proteins bind to _____.

the operator

The lac operon of Escherichia coli, a bacterium, is composed of __________.

three genes and two DNA control sequences: the promoter and the operator

A(n)___________ is a gene that encodes proteins that inhibit cell division. Such proteins normally help prevent cells from becoming cancerous.

tumor-suppressor gene

A DNA microarray is used to __________.

visualize patterns of gene expression