Final answer:
Proteins named 'cohesins' hold sister chromatids together, whereas 'condensins' help chromosomes condense during M-phase. The correct answer to the fill-in-the-blank question is 'e. cohesins/condensins'.
Step-by-step explanation:
The proteins that hold sister chromatids together are called cohesins, while the proteins that help chromosomes to condense during M-phase are called condensins. Therefore, the correct answer to the question is 'e. cohesins/condensins'.
Sister chromatids are identical copies of chromatin held together by cohesin at the centromere after DNA replication in the S phase of interphase. Cohesin ensures that the sister chromatids stay connected up until they are separated during anaphase. On the other hand, condensin proteins play a critical role during prophase of mitosis, where they help sister chromatids coil and condense. Condesins are important for arranging the chromatin into a highly compacted structure that is essential for proper chromosome segregation during cell division.