Antibiotics added to livestock feed have been found to increase their growth rate, reduce incidence of infection, reduces mortality and improve feed conversion ratio or feed efficiency.
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:
PP = 25%
Pp = 50%
pp = 25%
Explanation:
Using punnett square, we can predict the percentage probability of genotypes.
P p
P PP Pp
p Pp pp
In this cross we have,
PP = 1/4 = 25%
Pp = 2/4 = 50%
pp = 1/4 = 25%
We have ratio,
1 : 2 : 1
B causes all vegetation to freeze
<span>Edward Jenner is known as, “the father of
Immunology.” He was an English physician and scientist that made a smallpox
vaccine from the cowpox virus. This is known to be the world’s first vaccine
and this discovery is said have saved more lives than the work of any other
human being. Because of his work, World Health Organization declared smallpox
an eradicated disease in the 1979. Up to the year 2002, Jenner was still being
recognizes in the field of contemporary immunology and was even included in the
list of 100 Greatest Britons. </span>
