Tuberculosis vaccines are vaccinations intended for the prevention of tuberculosis. Immunotherapy as a defence against TB was first proposed in 1890 by Robert Koch. Today, the only effective tuberculosis vaccine in common use is bacilli Calmette-Guérin, first used on humans in 1921.
Answer:
a. the coordinated control of gene expression in bacteria
Explanation:
An operon in bacteria is a collection/cluster of genes that are under the control of a single promoter. It includes 3 components: a promoter, the genes and an operator. The operator is where a repressor binds, and the promoter is where transcription begins.
Operons allow organisms to control the expression of multiple genes in response to environmental cues
Fossils are physical evidence of preexisting organisms, either plant or animal. ... Fossils of any kind are useful in "reading the rock record," meaning they help us decipher the history of the earth. They can help us determine the geologic age and environment (the paleoenvironment) in which they were deposited.