C4 leaf has two distinct chloroplast-containing cell types: mesophyll and bundle sheath (or Kranz, German for “wreath”) cells

TLS Online TPP Program

#Id: 8895

#Unit 2. Cellular Organization

Monotelic attachment 

only one kinetochore can attach to microtubules

TLS Online TPP Program

#Id: 8897

#Unit 2. Cellular Organization

Sensing mechanism used by cells to detect incorrect chromosome attachments is based on tension.

TLS Online TPP Program

#Id: 8898

#Unit 2. Cellular Organization

If Amphitelic attachment occur  Microtubules pull kinetochores; cohesins resist this pulling force. The resulting tension leads to the outer kinetochore component Ndc80 being pulled away from the protein kinase Aurora B

TLS Online TPP Program

#Id: 8900

#Unit 2. Cellular Organization

The Aurora protein kinase family members Aurora A and Aurora B and their associated regulatory factors sense kinetochores that are not under tension and sever these microtubule attachments

TLS Online TPP Program

#Id: 8901

#Unit 2. Cellular Organization

Condensin association with chromosomes is facilitated by mitotic CDKs and Aurora B, which phosphorylate histone H2A, allowing condensins to bind chromatin.

TLS Online TPP Program

#Id: 8902

#Unit 2. Cellular Organization

Condensins package chromosomes by creating loops by forming intrachromosomal linkages and causes reduction in chromosome length, up to 10,000-fold in vertebrates.