Onion root tip has 16 chromosomes in each cell. How many chromosomes will the cell respectively have at G₁ phase, after S phase and after M phase?

1.	16, 32, 16	2.	16, 32, 8
3.	16, 16, 8	4.	16, 16, 16

Destruction of both centrosomes with a laser beam in an animal cell:

1. will prevent both mitosis and cytokinesis

2. prevents cytokinesis even if mitosis has been completed normally

3. permits cytokinesis but the daughter cells fail to enter a new S phase

4. prevents mitosis but permits cytokinesis

Which of the following statements is not true for cancer cells in relation to mutations?
1. Mutations in proto-oncogenes accelerate the cell cycle.
2. Mutations destroy telomerase inhibitor.
3. Mutations inactivate the cell control.
4. Mutations inhibit production of telomerase.

Telomerase is an enzyme which is a:
1. Ribonucleoprotein
2. Simple protein
3. RNA
4. Repetitive DNA

Which stage of meiosis is shown in the diagram given below?

In meiosis:

The mechanisms that contribute to the genetic variation arising from sexual reproduction include:

At which stage of mitosis are chromosomes usually photographed in the preparation of a karyotype?
1. Prophase
2. Metaphase
3. Anaphase
4. Telophase

A prolonged resting phase in oogenesis as seen in many vertebrate oocytes is called as:
1. Interkinesis
2. Diakinesis
3. Diplotene
4. Prometaphase II

Place stages of Prophase I in correct order.
1. diakinesis, diplotene, leptotene, pachytene, zygotene.
2. diplotene, leptotene, pachytene, zygotene, diakinesis.
3. leptotene, pachytene, diakinesis, diplotene, zygotene.
4. leptotene, zygotene, pachytene, diplotene, diakinesis