Q12.2-5CC. A kinetochore has been compared ... [FREE SOLUTION]

Chapter 12: Q12.2-5CC. (page 244)

A kinetochore has been compared to a coupling device that connects a motor to the cargo that it moves. Explain.

Short Answer

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The kinetochore attaches with the spindle fiber during the mitosis and meiosis process. The spindle consists of motor proteins that are the microtubules. This microtubule supports the movement of the chromosomes at the time of the division of the cell.

The cargo (chromosome) moves with the help of the motor protein found on the spindle fiber.

Step by step solution

Spindle fiber

Spindle fibers have microtubules; these microtubules have plus and minus ends. The plus end is present at the equator, while the minus end is present at the poles of the cells.

These help in the movement of the spindle chromosome linked to the kinetochore.

Kinetochore

The kinetochores are mainly formed of protein particles. There are two kinetochores on the chromosome placed in the opposite direction.

Spindle microtubules join the kinetochore at the prometaphase. Species to species, the kinetochore number differs.

Microtubules

The kinetochore microtubules help in the movement of the chromosomes. The chromosomes initiate traveling to the pole side from where the microtubules extend. This movement sometimes stops when the microtubules join from the opposite pole to link with the kinetochore.

In the next step, there is a tug of war. The chromosome starts moving in the opposite direction, and it gets settled in the midline of the cell called the metaphase plate.