Answer:
A substitution is a mutation that exchanges one base for another (i.e., a change in a single "chemical letter" such as switching an A to a G). Such a substitution could: change a codon to one that encodes a different amino acid and cause a small change in the protein produced.
Answer:
The correct answer is B high levels of lactose and high levels of cyclic AMP.
Explanation:
Lac operon contain 3 regulatory genes and 3 structural genes.In presence of lactose the repressor molecule that is encoded by Lac I gene cannot bound to the operator region.
Bacause the lactose interact with the repressor and change its conformation so that it cannot repress the expression of the structural genes of lac operon.
On the other hand cyclic AMP is a positive regulator of lac operon .The interaction of cyclic AMP with the promoter region of lac operon stimulates the binding of RNA polymerase in the promoter region to boost the expression of structural genes of lac operon such as Lac Z,Lac Y and Lac A.
As the plate moves from the ridge, sediments from erosion settle on the plate as it nears land.