9.Pathogenic micro-organisms present in host cells are killed by medicines called
(a) pain killer (b) antibodies
(c) antibiotics (d) vaccines

(c) Antibiotics

Explanation:

An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections they prevent the reproduction of bacteria, or they kill the bacteria, for example by stopping the mechanism responsible for building their cell walls.

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.