Question

Congression is a phenomenon of
A. Movement of sister chromatids towards the poles
B. Pairing of homologous chromosomes
C. Separation of paired chromosomes
D. Bringing the chromosomes on equator of spindle apparatus

Answer 1

In human cells, this process takes approximately 15 to 20 minutes and results in the creation of a metaphase sheet.

Complete answer:
The congression of chromosomes to the spindle equator is an important stage in mitosis. Congression is driven by at least two distinct mechanisms: (1) kinetochores sliding along the microtubule lattice using the CENP-E plus-end-directed motor, and (2) kinetochores bi-directing near the pole shifting to the equator by microtubule depolymerization-coupled dragging.
Chromosome congression is the mechanism by which chromosomes set at the spindle equator, equidistant from both spindle poles. This process takes 15-20 minutes in human cells and results in the creation of a metaphase layer. Chromosomes live in metaphase for a similar period of time before sister chromatids are segregated to opposite spindle poles in anaphase. Congressional correlates with the mechanism of chromosome bi-orientation, i.e. the creation of epithelial attachments in which sister kinetochores joined to microtubules originating from the opposite spindle poles. These epithelial attachments are consistent with oscillatory motion since the sister's transition between pole and pole change states. These chromosomes are able to conduct a congress when they undergo sustained motions towards the spindle equator.

Thus, the correct answer is option D. i.eBringing the chromosomes on the equator of spindle apparatus.

Note: The immediate transfer of chromosomes to the location of the metaphase plate is referred to as congression. In the congress, chromosomes come together on the equator of the spindle apparatus to form a metaphase sheet.