Explore a wide variety of cells, from bacteria to human neurons, using a compound light microscope. Select a sample to study, then focus on the sample using the coarse and fine focus controls of the microscope. Compare the structures found in different cells, then perform tests to see if the sample is alive.
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 brain and the spinal cord.
Answer:
compare and contrast of using solar panels versus wind turbines be sure to include how each works the cost of development in a general community/basic procedures for installments connections at a home etc
Explanation:
Physical arousal can facilitate passionate love. It is a naturally occurring and deeply embedded trait found within the DNA of living organisms. The purpose of such is the need to propagate the species in order to ensure its survival in the long run of evolution.
