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.
Answer:
Girl bye
Explanation:do your work
Oh gagahahs and the hormymoneya re better because I am wasting your trip ma
I think the best answer from the choices would be the first option. Icebergs float in the ocean since i<span>cebergs are composed of freshwater and freshwater is less dense then salt water. The ocean contains salts which contributes to its density which most likely would be higher with that of an iceberg.</span>
<span>The sun originates all the energy because without no sun, there is no plants, animals or anything .
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I think the parietal cells have canaliculi which secretes it
