An indirect measurement of the speed of molecules is temperature friction energy

temperature

Temperature is a degree of hotness or coldness measured on a definite scale on an instrument called as thermometer. It actually measures the kinetic energy of randomly moving particles or molecules of air in an atmosphere, living system or entity under study in a constant speed.

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.