Mutations which alter nucleotide sequence within a gene are :
frame shift mutations
base pair substitutions
both 'a' and 'b'
none of these
A.
frame shift mutations
Gene mutation or point mutation is the result of a change in the nucleotide sequence of the DNA molecule in a particular region of the chromosome. It occurs in the form of duplication, insertion, deletion, inversion or substitution of bases. Frame- shift mutation is the addition or deletion of a base that may change the reading frame of nucleotide sequence.
Base pair substitution is a type of mutation involving replacement or substitution of a single nucleotide base with another in DNA or RNA molecule.
Phytochrome occurs in two forms. In which form it promotes the germination of seeds of some species ?
Pfr forms
Pr forms
Both forms
None of these
Which organism was used by Beadle and Tatum to proposed one gene-one enzyme hypothesis ?
E. coli
Nostoc
Drosophila
Neurospora
Insect resistance transgenic cotton has been produced by inserting a piece of DNA from:
an insect
a bacterium
a wild relative of cotton
a virus
Which of the following pair is characterised by swollen lips, thick pigmented skin of hands and legs and irritability ?
Iodine - Goitre
Protein - Kwashiorkor
Thiamine - Beri-beri
Nicotinamide- Pellagra
When a tall plant with rounded seeds (TTRR) is crossed with a dwarf plant with wrinkled seeds (ttrr), the F1 generation consists of tall plants with rounded seeds. How many types of gametes an F1 plant would produce ?
One
Three
Four
Eight
