Question

What is the function of the fused kinetochore found on sister chromatids in prometaphase I?

a) To bind spindle fibers
b) To separate homologous chromosomes
c) To initiate DNA replication
d) To form the synaptonemal complex

Answer 1

The fused kinetochore's function on sister chromatids in prometaphase I is to bind spindle fibers, enabling the proper segregation of homologous chromosomes during meiosis.

Step-by-step explanation:

The function of the fused kinetochore found on sister chromatids in prometaphase I is to bind spindle fibers. During prometaphase I, the spindle fiber microtubules attach to the kinetochore proteins at the centromeres of homologous chromosomes. These kinetochore proteins are complex structures that ensure the correct attachment of chromosomes to the spindle apparatus. Once attached, the spindle fibers can pull the homologous chromosomes apart in the subsequent anaphase I. It should be noted that the separation of sister chromatids occurs later, in anaphase II, not in prometaphase I.

To clarify terminology, in prophase I of meiosis, the homologous chromosomes are held together by a synaptonemal complex, and cohesin proteins maintain their alignment. The attachment of kinetochores to spindle fibers in prometaphase I is pivotal for the proper alignment of chromosomes during metaphase I and their subsequent segregation during anaphase I.