During cell division, the spindle fibres attach to the chromosomes at a region called

1. chromocentre

2. kinetochore

3. centriole

4. chromomere

What would be the number of chromosomes of the aleurone cells of a plant with 42 chromosomes in its roots tip cells?

1. 21                       

2. 42                         

3. 63                   

4. 84

Best stage to observe shape, size and number of chromosomes is

1. interphase

2. metaphase

3. prophase

4. telophase

If a diploid cell is treated with colchicine then it becomes.

1. triploid                         

2. tetraploid 

3. diploid                           

4. monoploid 

Which one of the following precedes reformation of the nuclear envelope during M-phase of the cell cycle?

1. Decondensation from chromosomes and reassembly of the nuclear lamina

2. Transcription from chromosomes and reassembly of the nuclear lamina

3. Formation of the contractile ring and formation of the phragmoplast

4. Formation of the contractile ring and transcription from chromosomes.

Mitotic anaphase differs from metaphase in possessing.

1. same number of chromosomes and same number of chromatids

2. half number of chromosomes and half number of chromatids

3. half number of chromosomes and same number of chromatids

4. same number of chromosomes and half number of chromatids

The cell shown in the given diagram is in:

1. Early prophase

2. Late prophase

3. Metaphase

4. Telophase

The following cell, undergoing mitosis, is at:

1. Early prophase

2. Late prophase

3. Transition to metaphase

4. Early metaphase

Anaphase promoting complex (APC) is a protein degradation machinery necessary for proper mitosis of animal cells. If APC is defective in a human cell, which of the following is expected to occur?

(1) Chromosomes will not condense

(2) Chromosomes will be fragmented

(3) Chomosomes will not segregate

(4) Recombinantion of chromosome arms will occur 

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