Which cell organelle is covered by only one unit membrane ?
Nucleus
Plastids
Mitochondria
Lysosome
The S-phase of cell cycle is characterized by:
duplication of chromosome
shotening of chromosome
duplication of DNA
duplicatin of centriole
Phytotron is :
a controlled condition chamber for tissue
leaf culture process
special culture of plants
root culture process
CO2 acceptor in CAM plants is in :
mesophyll cells
bundle sheath
both
none of the above
A.
mesophyll cells
CAM or Crassulacean Acid Metabolism is found in succulent plants. In these plants CO2 is accepted in night via Phosphoenol pyruvate carboxylase enzyme in mesophyll cells.
During night, stomata open and CO2 is stored in vacuole in the form of malic acid. During day, it is decarboxylated and CO2 is transfered to ribulose 1,5 biphosphate (RuBP) of the calvin cycle within the same cell.
If centromere is the middle, the chromosome is called :
sub-metacentric
metacentric
acentric
telocentric
Which hormone is responsible for mobilization of storage food during seed germination ?
Auxin
Gibberellin
Cytokinin
Ethylene