Question

Microtubules capture chromosomes by binding to:

(a). telomere regions of the sister chromatids.
(b). cohesins on the sister chromatids.
(c). condensins on the condensed chromosomes.
(d). kinetochores on the sister chromatids.

Answer 1

Microtubules capture chromosomes by binding to kinetochores on the sister chromatids during mitosis, specifically in the stage called prometaphase.

Step-by-step explanation:

In mitosis, microtubules capture chromosomes by binding to kinetochores on the sister chromatids. During prometaphase, after the nuclear envelope has fragmented, spindle microtubules extend from the centrosomes and attach to the kinetochores, which are protein structures developed on the centromeric region of each sister chromatid. This attachment is crucial because it ensures that the sister chromatids will be properly segregated into the two new daughter cells. The kinetochore functions as a point of connection, facilitating the pulling of the chromatids apart to opposite poles during anaphase.

The options given in the question can be analyzed as follows: (a) the telomere regions are located at the ends of chromosomes and are not involved in microtubule attachment, (b) cohesins hold the sister chromatids together but are not the binding site for microtubules, (c) condensins help in chromosome condensation and are also not involved in the binding of microtubules. Hence, the correct answer to which the microtubules bind for capturing chromosomes is (d) kinetochores on the sister chromatids.