The answer has been given below.

Step-by-step explanation

Given that:

Within a population of 1800 lizards, the color brown (B) is dominant over the color green (b).

745 of the lizards are brown.

B = 745

b = 1800 - 745 = 1055

Percentage of color green lizard, which is homozygous recessive = (1055/1800) x 100 = 58.61 %

 

Now, 

Alleles: p+q=1

p=frequency of the dominant allele
q=frequency of the recessive allele

Genotypes: p²+2pq+q²=1

p^{??????????????2_???????}=frequency of homozygous dominant genotype
2pq=frequency of heterozygous genotype
q2=frequency of homozygous recessive genotype

We know that the frequency of homozygous recessive is 58.61%, which, as a decimal, is equal to 0.586

This means that

q² = 0.586

Take the square root of both sides to find q.

q=√0.586=0.7655

To find p, use the first equation.

p+0.7655=1

p= 1- 0.7655 = 0.2345

To find the frequency of the heterozygous population, find 2pq.

2pq=2(0.2345)(0.7655)=0.3590

 

 

Therefore, 

a. percentage of lizard that are heterozygous is 0.3590 or 35.9 %

 

b. The frequency of homozygous recessive individuals is 0.7655

 

c. The number of homozygous recessive individuals is 1055.