Afriend declares that chromosomes are held at the metaphase plate by microtubules that push on each chromosome from opposite sides. which of the following observations does not support your belief that the microtubules are pulling on the chromosomes?
(a)the jiggling movement of chromosomes at the metaphase plate
(b)the way in which chromosomes behave when the attachment between sister chromatids is severed
(c)the way in which chromosomes behave when the attachment to one kinetochore is severed
(d)the shape of chromosomes as they move toward the spindle poles at anaphase

The correct answer will be option-A.

Explanation:

During anaphase, the spindle microtubules help the segregation of the chromosomes from the center of the cell at the metaphase plate.

These microtubules get attached to the chromosomes at kinetochore which helps in pulling of the chromosomes to opposite poles.  The microtubules pull apart the sister chromatids when cohesin proteins degenerate.

The chromosomes do not show jiggling movement at the metaphase plate and thus, option-A is the correct answer.

answer: - b cells

explanation: -

so, the b cells mediate their action by identifying the antigens present on the surface of the pathogens and then producing antibodies in return to mediate its effect.