{"id":9573,"date":"2026-06-01T21:33:48","date_gmt":"2026-06-01T21:33:48","guid":{"rendered":"https:\/\/kapdec.com\/help\/?p=9573"},"modified":"2026-06-01T21:33:48","modified_gmt":"2026-06-01T21:33:48","slug":"hardy-weinberg-equilibrium","status":"publish","type":"post","link":"https:\/\/kapdec.com\/help\/hardy-weinberg-equilibrium\/","title":{"rendered":"Hardy-weinberg Equilibrium"},"content":{"rendered":"

Unit: Natural selection<\/strong><\/h2>\n

Chapter: Hardy Weinberg equilibrium<\/strong><\/h3>\n

Reference:<\/em><\/strong> Hardy-Weinberg principle, Importance<\/em><\/p>\n

Learning objectives<\/strong><\/p>\n

    \n
  • To describe the conditions under which allele and genotype frequencies will change in populations.<\/li>\n
  • To explain the impacts on the population if any of the conditions of Hardy-Weinberg are not met.<\/li>\n<\/ul>\n

    Hardy-Weinberg principle<\/strong><\/p>\n

      \n
    • Coined by G. H. Hardy and W. Weinberg, which describes the genetic structure of evolving population.<\/li>\n
    • Mutations introduce new genes into species resulting a change in gene frequencies.<\/li>\n
    • Gene frequency is defined as the frequency with which a particular allele occurs in the population.<\/li>\n<\/ul>\n

      According to Hardy-Weinberg principle allele frequencies in a population are stable and is constant from generation to generation i.e., the gene pool remains constant, called genetic equilibrium.<\/p>\n

      According to this principle a population is only at equilibrium when there is-<\/p>\n

        \n
      • No mutation<\/li>\n
      • No natural or artificial selection<\/li>\n
      • No gene flow (no gene migration)<\/li>\n
      • No genetic drift<\/li>\n
      • No genetic recombination<\/li>\n<\/ul>\n

        Individual frequency for may be named as P, q. etc. in a diploid organism p and q represent the frequency of allele A and a. the frequency of AA individuals in a population is p2<\/sup>. This can be stated in another way, i.e., the probability that an allele A with a frequency of p appears on both the chromosome of a diploid individual is the product of the probabilities i.e., p2<\/sup>. Similarly, of aa is q2<\/sup>, of Aa is 2 pq. Thus, is a binomial expansion of (p+q)2<\/sup>. It is possible to calculate all allele and genotype frequencies using the expressions allele frequency p+q = 1 and genotype frequency p2<\/sup>+2pq+q2<\/sup>=1<\/p>\n

        Importance<\/strong><\/p>\n

        For populations in the Hardy-Weinberg equilibrium, the equation connects allele frequencies to genotype frequencies. This equation allows us to compare a population's genetic structure over time to the expected genetic structure if the population were in Hardy-Weinberg equilibrium.<\/p>\n

        Solved examples<\/strong><\/p>\n

        Example 1<\/strong>. If the frequency of non-tasters of PTC – Paper in a population is 16%, find out the frequency of dominant allele and the percentage of homozygous dominant individuals in the population.<\/p>\n

         Solution 1<\/strong>– The frequency of non-tasters (i.e., homozygous recessive genotype) is 16%,<\/p>\n

        this means that q2<\/sup> = 16% = 16\/100 = 0.16<\/p>\n

        Value of q = 0.16, = 0.4.<\/p>\n

        As p + q = 1, p = (1 – 0.4) = 0.6<\/p>\n

        Frequency of dominant allele (p) will, therefore, be 0.6 or 60%.<\/p>\n

        Now, the frequency of homozygous dominant genotype (p2<\/sup>) = 0.6 × 0.6 = 0.36, or 36%<\/p>\n

        Example 2<\/strong>. Which Hardy-Weinberg factor represents the frequency of heterozygous individuals in a population?<\/p>\n

        a) p2<\/sup>   b)2pq   c) q2<\/sup>   d) p2<\/sup> + 2pq<\/p>\n

        Solution 2<\/strong>. b. The heterozygous individuals in a population are 2pq<\/p>\n

        Summary <\/strong><\/p>\n

          \n
        • Hardy-Weinberg principle is coined by G. H. Hardy and W. Weinberg, which describes the genetic structure of evolving population.<\/li>\n
        • According to Hardy-Weinberg principle allele frequencies in a population are stable and is constant from generation to generation i.e., the gene pool remains constant, called genetic equilibrium.<\/li>\n
        • The factors that affect the Hardy Weinberg principle includes gene flow, genetic drift, mutation, genetic recombination, and natural selection.<\/li>\n<\/ul>\n

           <\/p>\n","protected":false},"excerpt":{"rendered":"

          Unit: Natural selection Chapter: Hardy Weinberg equilibrium Reference: Hardy-Weinberg principle, Importance Learning objectives To describe the conditions under which allele and genotype frequencies will change in populations. To explain the impacts on the population if any of the conditions of Hardy-Weinberg are not met. Hardy-Weinberg principle Coined by G. H. Hardy and W. Weinberg, which […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[629],"tags":[],"class_list":["post-9573","post","type-post","status-publish","format-standard","hentry","category-ap-biology"],"_links":{"self":[{"href":"https:\/\/kapdec.com\/help\/wp-json\/wp\/v2\/posts\/9573","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kapdec.com\/help\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kapdec.com\/help\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kapdec.com\/help\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/kapdec.com\/help\/wp-json\/wp\/v2\/comments?post=9573"}],"version-history":[{"count":0,"href":"https:\/\/kapdec.com\/help\/wp-json\/wp\/v2\/posts\/9573\/revisions"}],"wp:attachment":[{"href":"https:\/\/kapdec.com\/help\/wp-json\/wp\/v2\/media?parent=9573"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kapdec.com\/help\/wp-json\/wp\/v2\/categories?post=9573"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kapdec.com\/help\/wp-json\/wp\/v2\/tags?post=9573"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}