You are investigating an abnormal eukaryotic cell line that makes all of its mRNAs much longer than the mRNAs from normal cells (that is, they have more nucleotides than usual). Intrigued, you examine the proteins in these abnormal cells and note that

many of them are either much longer or much shorter than the normal proteins from nonmutant cells. Assuming there is just one mutant defect in these cells, what is that defect?
A. A stop codon is mutated.
B. RNA polymerase does not recognize the terminator sequence.
C. Release factor is defective.
D. The spliceosome is nonfunctional.
E. The enzyme that adds the poly-A tail is defective.


Answer: D

Biology & Microbiology

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Answer the following statement true (T) or false (F)

Biology & Microbiology

If a man expresses an X-linked recessive trait, his ____________________ was either homozygous or heterozygous

for the traitFill in the blank(s) with the appropriate word(s).

Biology & Microbiology

Extremophilic bacteria are able to survive in hostile environments, including scalding hot water as well as springs and vents that reach temperatures over 100°C

Researchers studying these bacteria measured the function of a protein from an extremophile bacterium at 100°C, and they also measured the function of a similar protein from a human cell at 100°C. Which of the following results do you think the researchers obtained? A) The bacterial protein functioned normally, whereas the human protein did not. B) The human protein functioned normally, whereas the bacterial protein did not. C) The bacterial protein and the human protein both functioned normally. D) Neither the human protein nor the bacterial protein functioned normally.

Biology & Microbiology

One way to regulate gene expression is through the production of different sigma factors. These cause RNA polymerase to bind to different sets of promoters, thereby altering the pattern of gene expression.

Answer the following statement true (T) or false (F)

Biology & Microbiology