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
A.
One
Parent generation - Tall round seeds Dwarf wrinkled seeds
TTRR x ttrr
Gametes - TR tr
F1 generation - TtRr
Therefore, only one type of gametes is produced in F1 plants, i.e. TtRr or Tall round seeds.
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
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
Mutations which alter nucleotide sequence within a gene are :
frame shift mutations
base pair substitutions
both 'a' and 'b'
none of these
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
