Centromere is required for
1. Crossing over
2. Transcription
3. Cytoplasmic cleavage
4. Movement of chromosomes towards poles

During which phase(s) of cell cycle, amount of DNA in a cell remains at 4C level if the initial amount is denoted as 2C?

In 'S' phase of the cell cycle:                                                                                                                      
1. amount of DNA doubles in each cell.
2. amount of DNA remains same in each cell.   
3. chromosome number is increased  
4. amount of DNA is reduced  to half in each cell.

Spindle fibres attach on to:                                                                                                                                
1. Kinetosome of the chromosome
2. Telomere of the chromosome
3. Kinetochore of the chromosome
4. Centromere of the chromosome

A cell at telophase stage is observed by a student in a plant brought from the field. He tells his teacher that this cell is not like other cells at telophase stage. There is no formation of cell plate and thus the cell is containing more number of chromosomes as compared to other dividing cells. This would result in

During cell growth, DNA synthesis takes place in

Which of the following statements is NOT true of mitosis?
1. A single nucleus gives rise to two identical daughter nuclei.
2. The daughter nuclei are genetically identical to the parent nucleus.
3. The centromeres divide at the onset of anaphase.
4. Homologous chromosomes synapse in prophase.

In oocytes, the diplotene can last for months or years, since at this stage:
1. DNA proof reading and excision repair is performed
2. The proteins for metabolism are re-formed
3. The chromosomes condense and engage in RNA synthesis
4. The cell is temporarily withdrawn from the cell cycle

A ribbonlike structure consisting of three protein components and extending across the region of synapsed chromosomes during the prophase of meiosis, is called:
1. Phragmoplast
2. Phragmosome
3. Synaptonemal complex
4. Recombination nodule

The point of contact between paired chromatids during meiosis, resulting in a cross-shaped configuration and representing the cytological manifestation of crossing over is called:
1. Centromere

2. Centrosome

3. Chiasmata

4. Tetrad