Answer:
organisms that have more favorable traits tend to leave more offspring ... improved fitness of certain individuals in the population that allows for survival and reproduction. ... Based on H-W conditions, five major causes of evolution: ... factors that prevent organisms of two species from producing vigorous, fertile offspring
Explanation:
Answer:
Certain mutations in the repressor gene or operator sequence make the operon constitutive.
Explanation:
Lac operon is not expressed in the absence of lactose sugar. The repressor gene codes for the repressor protein which in turn binds to the operator region. The operator region of lac operon serves as a binding site for the repressor protein. Binding of repressor to the operator region of lac operon does not allow the RNA polymerase to transcribe the genes and the expression of operon is prevented.
Certain mutations in the repressor gene or operator sequence make the operon transcriptionally active even in the absence of lactose. A mutation in the repressor gene that results in the synthesis of non-functional repressor protein or no repressor protein would make the operon constitute. Similarly, a mutation in the operator sequence that does not allow an otherwise functional repressor protein to bind it would also result in the expression of the operon in the absence of lactose.
Answer:
Viruses cannot reproduce on their own, but inject their DNA into living cells in order to make copies of themselves.
Explanation:
A virus cannot reproduce itself outside the host because it lacks the complicated machinery that a [host] cell possesses.
