Explanation:
Genetic evolution is the meaning of biologic life, in that it is the why and how of it, as well as the stock of future biological existence. The genes that survive -- and in turn the organisms they make -- are the winners in the existence game. ... We owe our existence to this process, and our future depends on it.
<span>sulfuric acid - acid rain. Damages forests, limestone statues/buildings, lakes (alters pH) etc. Sulphur trioxide is a pollutant, which is also detrimental to health. Mark me the brainiest!</span>
Answer:
a. + glucose, + lactose = On
b. - glucose, - lactose = Off
c. + glucose, - lactose = Off
d. - glucose, + lactose = On
Explanation:
Lac operon has both types of control, repressible and inducible.
Whenever glucose level is low in the cell, an enzyme known as adenylyl cyclase raises the level of cAMP which forms a dimer with CRP protein and they both act as activator of lac operon and cause expression.
Apart from this, when lactose is present in the cell, β-galactosidase enzyme metabolizes lactose to form allolactose which causes allosteric repulsion in the lac repressor and causes its removal from the operator. As soon as repressor is removed lac operon gets activated.
In wild type lac operons, the expression of lac operon occurs when glucose level is low in the cell and lactose is present but in this mutant presence or absence of glucose will not make a difference because CRP will bind Plac promoter independent of cAMP level i.e. activator CRP will work even in high glucose concentration. If lactose is present then lac operon will always express so in option 'a & d' lac operon will express but in option 'b & c' it will not express.
the following is not a nucleotide is RNA