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

Quiscent centre is present in :

• root apex

• shoot apex

• parenchyma

• collenchyma

Cell membrane is made up of:

• protein

• cellulose

• lipids

• lipids, carbohydrates and protein

25.

Core of chlorophyll is formed by

• Fe

• Mn

• CH₃

• Mg

Phytotron is :

• a controlled condition chamber for tissue

• leaf culture process

• special culture of plants

• root culture process

Fruits are formed in :

• Brassica

• Fern

• Cycas

• Funaria

CO₂ acceptor in CAM plants is in :

• mesophyll cells

• bundle sheath

• both

• none of the above

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