The centrioles replicate during:
1. G₁ phase
2. S phase
3. G₂ phase
4. Early prophase

Bivalent chromosomes clearly appear as tetrads during:

1. Zygotene

2. Pachytene

3. Diplotene

4. Diakinesis

The beginning of diplotene is recognized by :

1. appearance of recombination nodules
2. Crossing over
3. Dissolution of synaptonemal complex
4. Appearance of chiasmata

Consider the given two statements:

l. During G₁ phase the cell is metabolically active and continuously grows but does not replicate its DNA.

ll. During G₂ phase, proteins are synthesized in preparation for mitosis while cell growth continues.

Of the two statements:
1. Only l is correct
2. Only ll is correct
3. Both l and ll are correct
4. Both l and ll are incorrect 

If the DNA content of an onion tip cell is 2C at the end of the M-phase, what would be its DNA content at the end of the S-phase?

1. C

2. 2C

3. 3C

4. 4C

In oocyte of some vertebrates, the stage of meiosis I that can last for months or years would be:

1. Zygotene

2. Pachytene

3. Diplotene

4. Diakinesis

When a cell stops growing, say due to shortage of nutrients, this will occur in which phase of the cell cycle?

1. ${\mathrm{G}}_0$

2. ${\mathrm{G}}_1$

3. S

4. ${\mathrm{G}}_2$

The following cell undergoing mitosis, is at :

1. Early prophase

2. Late prophase

3. Transition to metaphase

4. Early metaphase

Which of the following options gives the correct sequences of events during mitosis?

(1) Condensation → nuclear membrane disassembly → crossing over → Segregation → telophase

(2) Condensation → nuclear membrane disassembly → arrangement at equator → centromere division → Segregation → telophase

(3) Condensation → crossing over → nuclear membrane disassembly → Segregation → telophase

(4) Condensation → arrangement at equator → centromere division → Segregation → telophase

During cell growth, DNA synthesis takes place in

(1) S-phase                       

(2) ${\mathrm{G}}_1$-phase

(3) ${\mathrm{G}}_2$-phase                     

(4) M-phase