Meiosis - the cells divide to produce 4 haploid cells
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 first step is to identify the problem. There are factors to consider in keeping a plant or a tree healthy. These include water, oxygen, sunlight, soil, nutrients, climate, and other environmental conditions. If the environment seems to suit the other trees in the garden, ruling out other factors can be useful in determining why only one tree seems to be unhealthy. Once the problem is identified, a scientific investigation must be done to gather data and pieces of evidence which can explain why this event actually occurred. One of the best ways to gather evidence is through observing the tree and checking other signs which might identify if the tree is diseased. Once the gathered data are analyzed and the cause is identified, proceed in thinking of ways on how to solve it. In seeking a solution, it is best to ask information from experts and proper authorities.
A. Rate of growth of a seedling over two weeks.