All of these have treatments with antibiotics.
Answer:
a. purple allele (C) = 0.609, pink allele (c) = 0.391
b. purple homozygotes = 371, pink homozygotes = 153, heterozygotes = 476
Explanation:
Given -
Purple flowers - 847
Pink flowers - 153
The frequency of recessive genotype i.e

Frequency of recessive allele i.e q is equal to

As per hardy Weinberg's first equilibrium equation -

Frequency of purple homozygous species

Number of purple homozygous species 
Number of pink homozygous species 
Heterozygous species is equal to

Neurotransmitters is the word you're looking for.