Answer:
First two rings are thicker while the last two rings are thinner.
Explanation:
Due to the first two years of optimal growing conditions received by the tree, the width of trunk of the tree is thicker but due to drought conditions experienced by the tree during the most recent two years, there is very little increase occur in the width of the trunk because the tree is in stress condition and for that reason the ring of trunk is thinner as compared to first two years.
Answer:
The correct answer is a inducer(lactose) = acts by stepping on the gas pedal.
Explanation:
In lac operon lactose act as an inducer.Lactose exerts its action by binding with the repressor and inducing a conformation al change in the repressor molecule and prevent the later from binding to the operator region.
This ultimately result in the expression of the structural genes such as Lac Z ,Lac Y and Lac A.
According to the given question if the lac operon is described using a car analogy then the inducer lactose will act by stepping on the the gas pedal and this is the positive regulation of Lac operon.
The answer is letter A) through proteins.