DNA replication takes place during :
1. G1 - phase

2. G2 - phase

3. S - phase

4. Prophase

Consider the following two statements regarding enzyme action:
I. Co-factors play a crucial role in the catalytic activity of the enzyme.
II. Catalytic activity is reduced when the co-factor is removed from the enzyme.
Of the above statements:
1. Both I and II are correct and II explains I
2. Both I and II are correct but II does not explain I
3. I is correct but II is incorrect
4. I is incorrect but II is correct

Enzymes, vitamins and hormones are common in :
1. Being proteinaceous
2. Being synthesized in the body of organisms
3. Enhancing oxidative metabolism
4. Regulating metabolism

Which of the following statements can explain the fact that many scientists do not consider viruses as living organisms?

1. Metabolism and growth are defining properties of living organisms.

2. Anything less than a complete structure of a cell does not ensure independent living.

3. All cells arise from pre-existing cells

4. All biochemical reactions are catalyzed by enzymes.

A non-membrane bound organelle found in all cells is:
1. Centriole

2. Lysosome

3. Vacuole

4. Ribosome

Spindle fibers are attached to the chromosome in the region of :
1. Centrosome

2. Chromomere

3. Chromonema

4. Kinetochore

The four elements making 99 % of living system are :
1. CHOS

2. CHOP

3. CHON

4. CNOP

Identify the human cell for which the interphase period lasts the entire life of a person.
1. Hepatocyte
2. Bone marrow stem cells
3. Epidermal cell
4. Neuron

Glycogen is a polymer of :
1. Galactose
2. Glucose
3. Fructose
4. Sucrose

Identify the appendage present on the surface of some bacterial cells that help attach them to rocks in streams and also to the host tissues:

1. Flagella

2. Pili

3. Fimbriae

4. Cilia