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Question: Answered & Verified by Expert
The frequency of recessive allele in a population is 0.2. The number of heterozygotes in a population of 500 is
BiologyEvolutionNEET
Options:
  • A 150. 
  • B 240. 
  • C 160. 
  • D 64.
Solution:
2388 Upvotes Verified Answer
The correct answer is: 160. 

According to Hardy-Weinberg principle :
Frequency of dominant allele (A) = p

Frequency of recessive allele (a) = q = 0.2

Sum total of all the allelic frequencies is 1, i.e. p+ q = 1 
⇒  p + 0.2 = 1  ⇒  p = 0.8      

Frequency of homozygous dominant individuals = p × p = p2 

Frequency of homozygous recessive individuals = q × q = q2

Frequency of hetrozygous dominant individuals = 2pq = 2 × 0.8 × 0.2 = 0.32

Total Population = 500
Number of heterozygotes in population = 0.32 x 500 = 160

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