Which of these statements about enhancers is correct? a. They contain a unique base sequence called a TATA box. b. They are located only in 5′ untranslated regions. c. They are located only in introns. d. They are found both upstream and downstream from the transcription start site and are functional in any orientation.

In eukaryotes, what allows only certain genes to be expressed in different types of cells?

What is alternative splicing? a. phosphorylation that leads to different types of post-translational regulation b. mRNA processing that leads to different combinations of exons being spliced together c. folding that leads to proteins with alternative conformations d. the outcome of regulatory proteins that leads to changes in the life span of an mRNA

Compare and contrast the items in each pair: (a) enhancers and the E. coli CAP binding site

Compare and contrast the items in each pair: (b) promoter-proximal elements and the operator of the lac operon

Compare and contrast the items in each pair: (c) general transcription factors and sigma.

Predict how a mutation that caused continuous production of active p53 would affect the cell.

In the follow-up work to the experiment shown in Figure 19.6, the researchers used a technique that allowed them to see if two DNA sequences are in close physical proximity (association). They applied this method to examine how often an enhancer and the core promoter of the Hnf4a regulatory gene were near each other. A logical prediction is that compared with rats born to mothers fed a healthy diet, the Hnf4a gene in rats born to mothers fed a protein-poor diet would a. show no difference in how often the promoter and enhancer associated. b. never show any promoter–enhancer association. c. show a lower frequency of promoter–enhancer association. d. show a higher frequency of promoter–enhancer association.

One hypothesis for differences between humans and chimpanzees involves differences in gene regulation. A study using RNA-seq showed that the overall patterns of gene expression were similar in the liver and blood of the two species, but the expression patterns were strikingly different in the brain. How do these results relate to the hypothesis?

The Hawaiian bobtail squid (Euprymna scolopes) is able to glow from luminescent Vibrio fischeri bacteria held in its light organs. As it swims at night near the ocean surface, it adjusts the amount of light visible to predators below to match the light from the stars and moon. Predators have difficulty seeing the illuminated squid against the night sky. The bacteria glow in response to a molecule that regulates expression of genes involved in light-producing chemical reactions. The regulator controls production of the genes' mRNA. Therefore, the light-producing genes are under a. transcriptional control. b. translational control. c. post-translational control. d. negative control.