50%, don't know if you use pun nett squares but Google them, they simplify it so much.
R. r
r Rr. rr
r Rr. rr
C is the answer just did it
Spread of disease is density dependent because it is more severe the greater the population density as the disease would spread more easily. If there is low population density it would spread slower.
External adaption because it doesn’t adapt patterns
