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Site of attachment of spindle fibres in ...

Site of attachment of spindle fibres in chromosome lies

A

On the sides of centromere

B

After secondary constriction

C

Near telomere

D

Within centromere

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The correct Answer is:
To solve the question regarding the site of attachment of spindle fibers in chromosomes, we can follow these steps: ### Step-by-Step Solution: 1. **Understand the Structure of a Chromosome**: - A chromosome consists of two main parts: the centromere and the arms. The centromere is the constricted region that divides the chromosome into two sections. 2. **Identify the Centromere**: - The centromere is located in the center of the chromosome and is crucial for the movement of chromosomes during cell division. 3. **Locate the Kinetochores**: - Kinetochores are protein structures that form on the centromere during cell division. They are essential for the attachment of spindle fibers. 4. **Spindle Fiber Attachment**: - Spindle fibers, which are part of the mitotic spindle, attach to the kinetochores located on either side of the centromere. This attachment is vital for the proper segregation of chromosomes during cell division. 5. **Evaluate the Options**: - The question provides multiple-choice options regarding the site of spindle fiber attachment: - **A. On the sides of the centromere**: This is correct, as spindle fibers attach to the kinetochores located on either side of the centromere. - **B. After secondary constriction**: This is incorrect, as secondary constriction is not where spindle fibers attach. - **C. Near telomeres**: This is incorrect, as telomeres are the ends of the chromosome and do not have spindle fiber attachment. - **D. Within centromere**: This is also incorrect, as the attachment occurs at the kinetochores, which are adjacent to the centromere. 6. **Conclusion**: - The correct answer is **A. On the sides of the centromere**, as this is where the spindle fibers attach through the kinetochores.
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