The given diagram shows the ultra-structure of:

1. Centriole
2. Cilium
3. Flagellum
4. Centrosome

Both mature erythrocytes of humans and mature sieve tube cells of vascular plants:

1. are involved in transport of respiratory gases
2. lack a nucleus
3. continue to divide in an adult organism
4. do not exhibit any metabolism

Identify the incorrect statement regarding nucleolus:

Nucleoprotein fibers in the interphase nucleus called chromatin contain all the following except:

When the centromere in a chromosome is located close to its end, the chromosome is called as:

The number of correct statements amongst the given statements would be:

The triple helix structure of collagen was discovered by:
1. G. N. Ramachandran
2. Y. S. Subbarao
3. C. V. Raman
4. S. Chandrashekhar

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