When an extra base is inserted into the DNA
sequence of a gene, the
protein doesn't work.
Which explains why?

only b 

He used pea plants to study the patterns of heredity.

The rate that would change would be the  searching efficiency/attack rate. there are only two other rates in this model: the  growth rate of prey, and the  predator or consumer mortality rate.the  searching efficiency/attack rate is what indicates how effectively can a predator capture its prey whether in the searching process or actual capturing/attacking process.