The Designation His- Refers To

Question

The designation his- refers to
A) the genotype of bacteria that lack a functional gene for histidine synthesis AND bacteria that are auxotrophic for histidine.
B) the genotype of bacteria that have a functional gene for histidine synthesis AND bacteria that require addition of histidine to the growth medium.
C) the genotype of bacteria that have a functional gene for histidine synthesis AND bacteria that are auxotrophic for histidine.
D) the genotype of bacteria that lack a functional gene for histidine synthesis AND bacteria that have a hers gene.
E) the genotype of bacteria that lack a functional gene for histidine synthesis AND bacteria that do not require addition of histidine to the growth medium.

Accepted Answer

The designation his⁻ refers to bacteria that lack a functional gene for histidine synthesis, making them unable to synthesize histidine on their own. As a result, these bacteria are auxotrophic for histidine, meaning they require histidine to be added to their growth medium in order to survive and grow. This is because they cannot produce it due to the absence of the necessary gene.