The number of chromosomes in a certain type of cell division is halved. This kind of cell division occurs in

1. only testis
2. only ovary
3. both ovary and testis
4. all body cells

Synthesis phase in the cell cycle is called so for the synthesis of more of

1. RNA
2. RNA and proteins
3. DNA
4. Glucose

The chromosomes are duplicated in :

1. M phase
2. G₁ phase
3. S phase
4. G₂ phase

Nitrogenous bases are important components of DNA. They are formed by the combination of purines and pyrimidines with the help of hydrogen bonds. Which of the following options shows an incorrect combination ?

1. Adenine = Thymine
2. Guanine ≡ Cytosine
3. Cytosine ≡ Guanine
4. Thymine = Cytosine