Biological termModerate1 mark
2(iv)
Read the explanations given below and name the structures:
The point of attachment of two chromatids of a chromosome.
Topic: Centromere
Previous-year question practice database
Answer
Exam answer
CENTROMERE.
Explanation
A chromosome about to divide consists of two identical CHROMATIDS joined at a single constricted point, the CENTROMERE.
It does two jobs: it holds the chromatids together until anaphase, and it is the point to which the SPINDLE FIBRES attach in order to pull them apart.
Do not confuse it with the CENTRIOLE, which sounds similar but is quite different: centrioles are the paired structures in an animal cell that move to opposite poles and organise the spindle. Centromere = on the chromosome; centriole = in the cytoplasm.
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