What are the structures labeled “C” in the accompanying figure?
a. plasmodesmata
b. basement membranes
c. tight junctions
d. gap junctions
e. adhering junctions
ANSWER: d
You might also like to view...
Which of the following statements explains how N-formylmethionine (fMet) is incorporated only in response to the 5'-AUG initiation codon in E. coli, given that methionine has only one codon?
A. There is only one tRNA with the CAU anticodon. B. Only Met-tRNAmet can bind to a specific ribosomal entry site. C. The N-formyl group on methionine prevents fMet from entering interior positions in a polypeptide. D. fMet is always incorporated at interior AUG sites and then deformylated after translation.
Like bacteria, yeasts grow easily in culture. But why are they regarded as more useful for recombinant DNA technology?
a. They are more stable in culture than prokaryotes because they are not prone to bacteriophages. b. They are virtually harmless to humans so they are less risky to work with than prokaryotes. c. Because yeasts are eukaryotic, they exhibit post-transcriptional mRNA editing not performed by any prokaryotes such as Escherichia coli. d. They have longer lifespans so they do not have to be split and recultured as often.
Explain why the liver has a major role in protein metabolism. What will be an ideal response?
Axons of motor neurons first leave the spinal cord through the:
A) ventral roots. B) dorsal root ganglion. C) spinal nerve. D) dorsal roots.