1) Methylation, acetylation, and other histone modifications are important because:
Select one:
a. they are associated with the environmental and developmental cues that determine whether viral genes and genes in transposable elements are turned off or on.
b. they are associated with chromatin remodeling and affect gene transcription.
c. they are associated with cancer genes and their regulation.
d. they are associated with CpG island methylation and affect gene transcription.
2) In humans and other mammals, genes in the inactivated X chromosome:
Select one:
a. are not transcribed at all.
b. are expressed at exactly half the level of an autosomal gene.
c. are transcribed but not translated.
d. may be transcribed at a low level.
3) The Golgi apparatus
Select one:
a. Strings together amino acids to produce proteins.
b. Forms fats from glycerols and fatty acids.
c. Stores, modifies and packages proteins.
d. Is the site of carbohydrate breakdown.
4) Gene regulation can occur through:
Select one:
a. DNA modification.
b. histone modification.
c. RNA modification.
d. All of these choices are correct.
5) Enzymes present in the lumen of the Golgi apparatus are responsible for modifying proteins and lipids. Where were these proteins translated?
Select one:
a. ribosomes on the smooth endoplasmic reticulum
b. ribosomes on the rough endoplasmic reticulum
c. ribosomes in the nucleus
d. free ribosomes
6) The human body contains approximately 200 major cell types. They look and function differently from one another because:
Select one:
a. each has a slightly different genome and each expresses a different set of genes.
b. each has a slightly different genome.
c. each expresses the same set of genes, but in different orders at different times.
d. each expresses a different set of genes.
7) Which of the following statements about the ER is true?
Select one:
a. This organelle is a specialized vesicle that degrades damaged or unneeded macromolecules.
b. Some eukaryotic cells completely lack this organelle.
c. This organelle is found only in prokaryotes.
d. The rough ER is involved in the synthesis of transmembrane proteins and proteins that will be secreted.
8) During the translation of mRNA molecules, the new polypeptides are often directed to specific parts of the cell by the presence or absence of short sequences of amino acids called signal peptides. Which of the following would you expect to find in the polypeptides that will eventually fold to become ribosomal proteins?
Select one:
a. no signal peptide
b. a signal anchor peptide
c. an internal signal peptide
d. an amino terminal signal peptide
9) During the translation of mRNA molecules, the new polypeptides are often directed to specific parts of the cell by the presence or absence of short sequences of amino acids called signal peptides (or signal sequences). Which of the following would you expect to find in the polypeptide that will eventually fold to become a histone protein?
a. a nuclear localized signal.
b. a signal recognition particle (SRP)
c. no signal peptide
d. a signal anchor peptide
10) Modifications of histone tails can:
Select one:
a. affect chromatin structure.
b. activate transcription of some genes.
c. repress transcription of some genes.
d. affect expression of some genes in response to the environment.
e. All of these choices are correct.