In spite of the fact that this situation is probably not going to occur, rotenone is poisonous in light of the fact that it meddles with the electron transport chain (ETC) in mitochondria, so NADH would develop as recommended.
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.
Gametes
When a cell divides by way of mitosis, it produces two clones of itself, each with the same number of chromosomes. When a cell divides by way of meiosis, it produces four cells, called gametes. Gametes are more commonly called sperm in males and eggs in females.
Answer;
Evolution
Mutations such as polyploidy and crossing over provide the genetic basis for evolution.
Explanation;
Evolution is the change in the characteristics or traits of a species over several generations and relies on the process of natural selection.
It occurs when some individuals or some alleles (alternative form of gene) reproduce themselves more than others,increasing their prevalence in subsequent generation.
Polypoidy and crossover brings about mutations that cause changes in characteristics and traits over time resulting to evolution.
