Modelling refers to using a diagrammatic representation to present a particular event or biological activity.
The two maps shown are very good for representing/modelling mitosis.
Advantages
- They clearly lists the various steps involved in mitosis and as well included the process of cell division starting from the interphase stage (for the second diagram).
- The M phase was also clearly explained in the first diagram.
Disadvantages
- The first pictorial diagram had to labelling to depict the name of each particular phase and makes understanding difficult.
- The second diagram fails to show pictorial representation of what could have exactly happened in each stage in the process of cell division.
Learn more about cell division: brainly.com/question/796780
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.
D. Are made of cells and DNA
DNA is genetic material in living organisms that is transferred from the parents. Cells and this DNA gives organisms personalized traits. Hope this helped !!
Answer:
Diffusion
Explanation:
Diffusion is the process through which molecules in the cell are kept in balance with those outside the cell.
Diffusion is the process by which molecules move from an area of higher concentration to an area of lower concentration.
Through the above mechanism, molecules having higher concentration in the cell move out of the cell and vice versa thereby maintaining the balance of molecules in and outside the cell.
