First natural cytokinin was discovered by :
Skoog and Miller
Letham
Benson and Calvin
Thimann and Went
B.
Letham
First natural cytokinin was obtained from unripe maize grains or Kernels. It is known as zeatin or 6- hydroxy 3- methyl trans butenyl amino purine.
C4 plants, synthesis of sugars/final CO2 fixation occurs in:
palisade cells
spongy cells
undifferentiated mesophyll cells
bundle sheath cells
Cook cambium and vascular cambium are :
parts of secondary xylem and phloem
parts of pericycle
lateral meristems
apical meristems
Which of the following is not vestigial in man ?
Tail vertebrae
Nails
Nictitating membrane
Vermiform appendix
The number of hydrogen bonds between adenine and thymine in a DNA molecule is :
two
three
four
eight
Major role of minor elements inside living organisms is to act as :
binder of cell structure
constituent of hormone
building blocks of important amino acids
cofactor of enzymes
A eukaryotic gene contains two kinds of base sequences. Which of these plays an important role in protein synthesis?
Introns
Exons
Both 'a' and 'b'
None of the above