Imagine that you have set up a genetic screen to identify E. coli mutants that cannot metabolize the amino acid tryptophan for energy. Beginning with a master plate containing many colonies, you prepare replica plates on medium with glucose or tryptophan as the only energy source. You would look for colonies that _____.
A) cannot grow on either type of media
B) can grow on both types of media
C) can grow only on the plates with tryptophan
D) can grow only on the plates with glucose
Answer: D
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Small regulatory RNAs are known to be:
A. bound by Drosha in the cytoplasm. B. recognized by DGCR8 in the nucleus. C. cleaved by Dicer in the nucleus. D. transported to the nuclease as fully processed miRNA.
A lac Y- mutant would
A) be constitutive. B) no longer be induced by the presence of lactose. C) not have ?-galatosidase activity. D) transport lactose into the cell effectively. E) metabolize lactose.
Individuals with a genetic variant in the promoter region of the MAOA gene display violent behavior, independent of
environmental factors. a. True b. False
Replication of DNA molecule produce
A. Three DNA and one RNA molecules B. One DNA and one mRNA molecules C. Two different molecules of DNA D. One tRNA and one rRNA molecules E. Two exact copies of DNA molecules