Correct option is D
Explanation-
Statement A: "Though cohesin is important for pairwise alignment of the chromosomes on the mitotic spindle, it is not important for the generation of tension across the centromere." - INCORRECT
Cohesin is crucial for generating tension across sister chromatids at the centromere, which ensures proper chromosome alignment and segregation. Without tension, the spindle assembly checkpoint would be activated, preventing anaphase onset.
Statement B: "Cohesin binds to the chromosome even before the initiation of S-phase." - CORRECT
Cohesin is loaded onto chromosomes in G1 phase, before DNA replication begins. It becomes cohesive during S-phase when the replication fork passes through it.
Statement C: "In fission yeast, centromere-specific localization of Moa1 and Rec8 regulates the orientation of kinetochores at meiosis-I." - CORRECT
In meiosis-I, Moa1 and Rec8 play key roles in ensuring monopolar attachment of sister kinetochores, which is essential for homolog segregation.
Statement D: "Cohesin exhibits uniform distribution/localization pattern across the chromosomal length." - INCORRECT
Cohesin does not distribute uniformly. It is enriched at centromeres, pericentromeric regions, and specific loci depending on the phase and function.
Statement E: "Polo/Cdc5 is a positive regulator of Separase, an endopeptidase that facilitates opening of the cohesin ring." - CORRECT
Polo-like kinase Cdc5 activates Separase, which cleaves Scc1/Rad21, a subunit of the cohesin complex, allowing chromatid separation.
Correct Statements : B, C, and E
Final answer - Option d ( B, C and E )
