NEETBotanyCell Cycle and Cell Division
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): During metaphase, chromosomes are moved to the spindle equator and get aligned along the metaphase plate. Reason (R): Spindle fibres attach directly to the centromeres of chromosomes to pull them towards the equator. In the light of the above statements, choose the most appropriate answer from the
Options
- ABoth (A) and (R) are true and (R) is the correct explanation of (A)
- BBoth (A) and (R) are true but (R) is not the correct explanation of (A)
- C(A) is true but (R) is false
- D(A) is false but (R) is true
Correct answer
C. (A) is true but (R) is false
Step-by-step solution
Assertion (A) is true as the defining feature of metaphase is the movement of chromosomes to the spindle equator, where they align to form the metaphase plate. Reason (R) is false because spindle fibres do not attach directly to the centromeres. According to NCERT, spindle fibres attach to small disc-shaped structures at the surface of the centromeres called kinetochores, which serve as the actual sites of attachment. Answer: (A) is true but (R) is false