Explain an earthworm’s movement on a plain glass tile

Earthworms have microscopic hairs or bristles all over their body which provide the necessary traction while movement. ... Glass is smooth in nature so earthworms cannot move as the setae will not get sufficient surface support to move the body.

Explanation:

c) 50% there are four chromosomes. after crossing over, 2 of the four have been changed. that means any gamete has a 2 in 4 chance or 50% chance of receiving the mutated chromosome.