An enzyme brings about :
1. Decrease in reaction time
2. Increase in reaction time
3. Increase in activation energy
4. Reduction in activation energy

Consider the following functions:
I. Replication of DNA along with the synthesis of nuclear proteins such as histones
II. Duplication of centriole
III. Synthesis of energy rich compounds and proteins
Which of the above functions are carried out by a plant cells before it divides?

1. I only

2. I, and II

3. I and III

4. I, II, and III

Algal cell walls are made up of:
1. Cellulose, Galactans, Mannans and Minerals
2. Cellulose, Hemicellulose, Pectins and Proteins
3. Cellulose, Pectins, Mannans and Minerals
4. Cellulose, Hemicellulose, Mannans and Pectins

The high energy bonds in an ATP molecule are between :
1. Ribose and nitrogenous base
2. Nitrogenous base and phosphate
3. Ribose and phosphate
4. Phosphate groups

Which of the following is not considered as a part of the endo-membranous system of a eukaryotic cell?
1. Lysosomes
2. Vacuoles
3. Endoplasmic reticulum
4. Peroxisomes

The duration of which of the following is constant in most cell types?
1. G1 phase, S phase and G2 phase
2. S phase, M phase and G1 phase
3. S phase, G2 phase and M phase
4. G1 phase, M phase and G2 phase

In competitive inhibition, if the concentration of the substrate is increased :
1. the rate of the reaction is increased
2. the rate of the reaction is decreased
3. the rate of the reaction is not affected
4. the reaction direction is reversed

In animal cells steroidal hormones are synthesized in the:
1. Rough endoplasmic reticulum
2. Smooth endoplasmic reticulum
3. Golgi apparatus
4. Lysosomes

An important site of the formation of glycoproteins and glycolipids in a eukaryotic cell is the:
1. Rough endoplasmic reticulum
2. Smooth endoplasmic reticulum
3. Golgi apparatus
4. Lysosomes

A glycosidic bond connects :
1. two monosaccharides
2. two amino acids
3. two fatty acids
4. a fatty acid and a glycerol