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

In the cells of a human male body, the number of autosomes is :

1. 23 pairs
2. 22 pairs
3. 1 pair
4. 46 pairs

After a mitotic cell division, a human female cell will have :

1. 22 + X chromosomes
2. 44 + XY chromosomes
3. 44 + XX chromosomes
4. 22 + XX chromosomes

The phase of karyokinesis which is almost the reverse of prophase is :

1. Interphase
2. Metaphase
3. Anaphase
4. Telophase