ara+ and lac+ are genes required for
metabolizing the sugars arabinose and lactose, respectively, and
ala+ and leu+ are genes required for synthesizing
the amino acids alanine and leucine. You are given the following
strains:
Strain 1: leu- ala+ ara+
lac+
Strain 2: leu+ ala- ara+
lac-
Strain 3: leu+ ala+ ara+
lac-
Strain 4: leu+ ala- ara-
lac-
Which of these strains will grow on minimal media with
glucose?
A.
2, 4
B.
2, 3, 4
C.
3
D....