The lac operon consists of
four regulatory genes only
one regulatory gene and three structural genes
two regulatory genes and two structural genes
two regulatory genes and two structural genes
B.
one regulatory gene and three structural genes
Lac operon is the operon that regulates lactose metabolism in the bacterium Escherichia coli. Its form wast first postulated in 1961 by Francois Jacob and Jacques Monod to explain the control of β- galactosidase synthesis and for this work, they were awarded Nobel Prize. Lac operon system or inducible operon system consists of regulator gene (i) promoter gene (z, y and a), repressor protein and inducer.
Drosophila
Study the pedigree chart of a certain family given below and select the correct conclusion which can be drawn for the character.
The female parent is heterozygous
The parents could not have a had a normal daughter for this character
The trait under study could not be colour blindness
The trait under study could not be colour blindness
Study the cycle shown below and select the option which gives correct words for all the four blanks A, B, C and D.
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A |
B |
C |
D |
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Nitrification |
Ammonification |
Animals |
plants |
|
A |
B |
C |
D |
|
Dentirificiation |
Ammonification |
Plants |
Animals |
|
A |
B |
C |
D |
|
Nitrification |
Denitrification |
Animals |
Plants |
|
A |
B |
C |
D |
|
Nitrification |
Denitrification |
Animals |
Plants |
Given below is the diagram of a bacteriophage in which one of the options, all the four parts A, B, C and D are correct?
|
A |
B |
C |
D |
|
Tail fibres |
Head |
Sheath |
Collar |
|
A |
B |
C |
D |
|
Sheath |
Collar |
Head |
Tail fibres |
|
A |
B |
C |
D |
|
Head |
Collar |
Sheath |
Tail fibres |
|
A |
B |
C |
D |
|
Head |
Collar |
Sheath |
Tail fibres |
