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


Ans: D) can grow only on the plates with glucose

Biology & Microbiology

You might also like to view...

Which of the following ECM molecules is probably the most abundant organic molecule on Earth?

A. proteoglycans B. collagen C. chitin D. cellulose E. laminins

Biology & Microbiology

Transcription of ribosomal RNA is primarily the function of

A) primase. B) RNA polymerase I. C) RNA polymerase II. D) RNA polymerase III. E) mitochondrial RNA polymerase.

Biology & Microbiology

Which of the following is a reactant or product during the process of photosynthesis?

a. oxygen b. FADH 2 c. NADH d. pyruvate

Biology & Microbiology

With __________, offspring inherit the same number and kinds of genes from one parent. Fill in the blank(s) with the appropriate word(s)

Biology & Microbiology