How would you classify the spread of disease as an effect of air travel

Disease spread can affect air travel really badly because it can be so easy for anyone to get infected with how crowded airports can be. This usually results in extra safety steps taken up to cancelled flights due to closed borders. A popular example of this is the current pandemic crisis.

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.