Problem Set 10

a.) express different genes.

Muscle cells differ from nerve cells mainly because they a.) express different genes. b.) contain different genes. c.) have unique ribosomes. d.) use different genetic codes.

b.) Proto-oncogenes normally help regulate cell division.

Proto-oncogenes can change into oncogenes that cause cancer. Which of the following best explains the presence of these potential time bombs in eukaryotic cells? a.) Proto-oncogenes first arose from viral infections. b.) Proto-oncogenes normally help regulate cell division. c.) Proto-oncogenes are mutant versions of normal genes. d.) Proto-oncogenes are genetic "junk."

c.) transcriptional control of gene expression.

The functioning of enhancers is an example of a.) a eukaryotic equivalent of prokaryotic promoter functioning. b.) the stimulation of translation by initiation factors. c.) transcriptional control of gene expression. d.) post-translational control that activates certain proteins.

c.) the removal of introns and alternative splicing of exons

Which of the following is an example of post-transcriptional control of gene expression? a.) gene amplification contributing to cancer b.) the binding of transcription factors to a promoter c.) the removal of introns and alternative splicing of exons d.) the addition of methyl groups to cytosine bases of DNA

d.) It is the same as the DNA in one of your liver cells.

Which of the following statements about the DNA in one of your brain cells is true? a.) Most of the DNA codes for protein. b.) Each gene lies immediately adjacent to an enhancer. c.) The majority of genes are likely to be transcribed. d.) It is the same as the DNA in one of your liver cells.

d.) the rate at which the mRNA is degraded.

Within a cell, the amount of protein made using a given mRNA molecule depends partly on a.) the number of introns present in the mRNA. b.) the degree of DNA methylation. c.) the types of ribosomes present in the cytoplasm. d.) the rate at which the mRNA is degraded.