{"id":40839,"date":"2023-08-03T14:54:54","date_gmt":"2023-08-03T09:09:54","guid":{"rendered":"https:\/\/microbenotes.com\/hardy-weinberg-equilibrium\/"},"modified":"2023-08-03T14:54:54","modified_gmt":"2023-08-03T09:09:54","slug":"hardy-weinberg-equilibrium","status":"publish","type":"post","link":"https:\/\/microbenotes.com\/hardy-weinberg-equilibrium\/","title":{"rendered":"Hardy-Weinberg Equilibrium"},"content":{"rendered":"<ul>\n<li><span style=\"color: #000000;\">The\u00a0Hardy\u2013Weinberg principle, also known as the\u00a0Hardy\u2013Weinberg equilibrium, model, theorem, or\u00a0law explains that\u00a0allele\u00a0and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences.<\/span><\/li>\n<li><span style=\"color: #000000;\">The law was proposed by a British mathematician Hardy and a German physician Weinberg (1908) independently.<\/span><\/li>\n<li><span style=\"color: #000000;\">Both the ideas together is called as the Hardy-Weinberg law equilibrium after their names.<\/span><\/li>\n<li><span style=\"color: #000000;\">It states that <strong>both gene frequencies and genotype frequencies will remain constant from generation to generation in an infinitely large interbreeding population in which mating is at random and no selection, migration or mutation occurs<\/strong>.<\/span><\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-1482\" src=\"https:\/\/microbenotes.com\/wp-content\/uploads\/2018\/10\/Hardy-Weinberg-Equilibrium.jpg\" alt=\"Hardy-Weinberg Equilibrium\" width=\"800\" height=\"420\" \/><\/p>\n<p><span style=\"color: #000000;\">Assuming certain conditions, the Hardy-Weinberg equilibrium thus proposes that allelic frequency of a population will stay stable over time.<\/span><\/p>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_65 counter-hierarchy ez-toc-counter ez-toc-custom ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title \" >Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #0a0a0a;color:#0a0a0a\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #0a0a0a;color:#0a0a0a\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/microbenotes.com\/hardy-weinberg-equilibrium\/#conditions-of-the-hardy-weinberg-population-are\" title=\"Conditions of the Hardy-Weinberg population are:\">Conditions of the Hardy-Weinberg population are:<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/microbenotes.com\/hardy-weinberg-equilibrium\/#the-equations\" title=\"THE EQUATIONS\">THE EQUATIONS<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/microbenotes.com\/hardy-weinberg-equilibrium\/#inference\" title=\"Inference\">Inference<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/microbenotes.com\/hardy-weinberg-equilibrium\/#applications\" title=\"Applications\">Applications<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/microbenotes.com\/hardy-weinberg-equilibrium\/#sample-problem-involving-hardy-weinberg-equilibrium\" title=\"SAMPLE PROBLEM INVOLVING HARDY-WEINBERG EQUILIBRIUM\">SAMPLE PROBLEM INVOLVING HARDY-WEINBERG EQUILIBRIUM<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/microbenotes.com\/hardy-weinberg-equilibrium\/#answer\" title=\"ANSWER\">ANSWER<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/microbenotes.com\/hardy-weinberg-equilibrium\/#references\" title=\"References\">References<\/a><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"conditions-of-the-hardy-weinberg-population-are\"><\/span><span style=\"color: #000000;\"><strong>Conditions of the Hardy-Weinberg population<\/strong> are:<\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<ul>\n<li><span style=\"color: #000000;\">The population must be large.<\/span><\/li>\n<li><span style=\"color: #000000;\">Mating must be random, with no selection for certain genotypes.<\/span><\/li>\n<li><span style=\"color: #000000;\">There must be no emigration or immigration.<\/span><\/li>\n<li><span style=\"color: #000000;\">There may be no mutations.<\/span><\/li>\n<li><span style=\"color: #000000;\">There may be no incestuous mating.<\/span><\/li>\n<\/ul>\n<h2><span class=\"ez-toc-section\" id=\"the-equations\"><\/span><span style=\"color: #000000;\"><strong>THE EQUATIONS<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<ul>\n<li><span style=\"color: #000000;\">Suppose in a population of plant species, a gene has two allele, \u2018A\u2019 n \u2018a\u2019 having frequency \u2018p\u2019 n \u2018q\u2019 respectively.<\/span><\/li>\n<li><span style=\"color: #000000;\">The frequencies of their genotypes AA, 2Aa and aa are p,2pq and q.<\/span><\/li>\n<li><span style=\"color: #000000;\">According to this law, the frequency of p and q in a population remains constant generation after generation unless there\u2019s any factor\u2019s influence.<\/span><\/li>\n<\/ul>\n<p><span style=\"color: #000000;\">Mathematically,<\/span><\/p>\n<p><span style=\"color: #000000;\">If there is a gene with two alleles, A and a.<\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 p + q = 1\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0(Eq. 1)<\/span><\/p>\n<ul>\n<li><span style=\"color: #000000;\">p = frequency of A allele<\/span><\/li>\n<li><span style=\"color: #000000;\">q = frequency of a allele<\/span><\/li>\n<\/ul>\n<p><span style=\"color: #000000;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 p<sup>2<\/sup> + 2pq + q<sup>2<\/sup> = 1 \u00a0\u00a0\u00a0\u00a0(Eq. 2)<\/span><\/p>\n<ul>\n<li><span style=\"color: #000000;\">p<sup>2<\/sup> = frequency of AA genotype<\/span><\/li>\n<li><span style=\"color: #000000;\">2pq = frequency of Aa genotype<\/span><\/li>\n<li><span style=\"color: #000000;\">q<sup>2<\/sup> = frequency of aa genotype<\/span><\/li>\n<\/ul>\n<h2><span class=\"ez-toc-section\" id=\"inference\"><\/span><span style=\"color: #000000;\"><strong>Inference<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"color: #000000;\">As shown by Hardy and Weinberg, alleles segregating in a population tend to establish equilibrium with reference to each other. Thus, if two alleles should occur in equal proportion in a large, isolated breeding population and neither had a selective or mutational advantage over the other, they would be expected to remain in equal proportion generation after generation.<\/span><\/p>\n<h2><span class=\"ez-toc-section\" id=\"applications\"><\/span><span style=\"color: #000000;\"><strong>Applications<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"color: #000000;\">The Hardy\u2013Weinberg principle may be applied in two ways, either a population is assumed to be in Hardy\u2013Weinberg proportions, in which the genotype frequencies can be calculated, or if the genotype frequencies of all three genotypes are known, they can be tested for deviations that are\u00a0statistically significant.<\/span><\/p>\n<h2><span class=\"ez-toc-section\" id=\"sample-problem-involving-hardy-weinberg-equilibrium\"><\/span><span style=\"color: #000000;\"><strong>SAMPLE PROBLEM INVOLVING HARDY-WEINBERG EQUILIBRIUM<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"color: #000000;\"><strong>QUESTION<\/strong><\/span><\/p>\n<p><span style=\"color: #000000;\">Sickle cell anemia, an autosomal recessive disease, occurs in 1 of every 400 African-American births. What is the frequency of carriers of the sickle cell gene in this population?<\/span><\/p>\n<h2><span class=\"ez-toc-section\" id=\"answer\"><\/span><span style=\"color: #000000;\"><strong>ANSWER<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"color: #000000;\">Carriers (or heterozygotes) are represented by 2pq, so we need to solve for p and q.<\/span><\/p>\n<p><span style=\"color: #000000;\">We are told that q <sup>2<\/sup> is equal to 1\/400 or 0.0025.<\/span><\/p>\n<p><span style=\"color: #000000;\">Thus, q = 0.05<\/span><\/p>\n<p><span style=\"color: #000000;\">We know that p + q = 1, so p = 1 \u2013 q. In this case,<\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 p = 1 \u2013 0.05 = 0.95.<\/span><\/p>\n<p><span style=\"color: #000000;\">We then solve for 2pq, which is equal to 2(0.95) (0.05) or 0.095.<\/span><\/p>\n<p><span style=\"color: #000000;\">So 95 of every 1000 African- Americans carry the sickle cell gene.<\/span><\/p>\n<h2><span class=\"ez-toc-section\" id=\"references\"><\/span><span style=\"color: #000000;\"><strong>References<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<ol>\n<li><span style=\"color: #000000;\">Verma, P. S., &amp; Agrawal, V. K. (2006). Cell Biology, Genetics, Molecular Biology, Evolution &amp; Ecology (1 ed.). S .Chand and company Ltd.<\/span><\/li>\n<li><span style=\"color: #000000;\">Gardner, E. J., Simmons, M. J., &amp; Snustad, D. P. (1991).\u00a0Principles of genetics. New York: J. Wiley.<\/span><\/li>\n<li><span style=\"color: #000000;\">https:\/\/www.slideshare.net\/santoshpathak817\/hardyweinberg-law<\/span><\/li>\n<li><span style=\"color: #000000;\">https:\/\/en.wikipedia.org\/wiki\/Hardy%E2%80%93Weinberg_principle<\/span><\/li>\n<li><span style=\"color: #000000;\">Baron J.S. and Lee I.C. Biochemistry &amp; Genetics. Second Edition McGraw Hill Medical: New York.<\/span><\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"<p>The\u00a0Hardy\u2013Weinberg principle, also known as the\u00a0Hardy\u2013Weinberg equilibrium, model, theorem, or\u00a0law explains that\u00a0allele\u00a0and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary &#8230; <a title=\"Hardy-Weinberg Equilibrium\" class=\"read-more\" href=\"https:\/\/microbenotes.com\/hardy-weinberg-equilibrium\/\" aria-label=\"Read more about Hardy-Weinberg Equilibrium\">Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":40838,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6193],"tags":[2986,2981,2985,2983,2984,2982,2987],"custom":{"td_video":"","featured_image":"https:\/\/microbenotes.com\/wp-content\/uploads\/2018\/10\/Hardy-Weinberg-Equilibrium.jpg","author":{"name":"Sagar Aryal","avatar":"https:\/\/secure.gravatar.com\/avatar\/862472ea06500d4318f1ad82addb608e?s=96&d=mm&r=g"},"categories":[{"term_id":6193,"name":"Genetics","slug":"genetics","term_group":0,"term_taxonomy_id":6193,"taxonomy":"category","description":"<strong>Genetics is a branch of natural science that deals with heredity due to the transmission of genes, gene regulation, and gene manipulation.<\/strong>\r\n<ul>\r\n \t<li>Genetics is a connecting link between many disciplines like microbiology, biotechnology, medicine, and agriculture.<\/li>\r\n \t<li>Studies involving genes and chromosomes of living beings began quite late as it requires significant advances in the microscopy area.<\/li>\r\n \t<li>The influence of heredity and its application of cultivation and production improved organisms, however, had been recognized since ancient times.<\/li>\r\n \t<li>The study of genes and genetics began as a major concept after studies made by Mendel on pea plants. It was further strengthened and flourished by the works of Morgan.<\/li>\r\n \t<li>Eventually, genetics became a distinct area of study with the identification of genes and the study of genes at different levels, including their role in the cell, their regulation, and their expression.<\/li>\r\n \t<li>Initially, genetics was limited to understanding the concept and process of heredity via techniques like the formation of Punnet\u2019s square. With the development of techniques like X-ray diffraction, the structure of DNA, and the presence of genetic code were established. This paved the way for modern genetics.<\/li>\r\n \t<li>Modern genetics focuses on the chemical composition of structures found in genes like the DNA that influences the chemical reactions taking place in the cell.<\/li>\r\n \t<li>Gene expression is influenced by two major factors; the genetic composition and the influence of the environment.<\/li>\r\n \t<li>The influence of the environment on gene expression can be distinctly observed in green plants where the gene responsible for the formation of chlorophyll is only expressed in the presence of sunlight.<\/li>\r\n \t<li>\u00a0Genes, through the proteins they encode, determine how efficiently foods and chemicals are metabolized, how effectively toxins are detoxified, and even how vigorously infections are targeted.<\/li>\r\n \t<li>Processes like mutations are now a significant cause of major genetic diseases. The mutations might arise due to a complex combination of genetic, behavioral, and environmental factors.<\/li>\r\n<\/ul>","parent":0,"count":79,"filter":"raw","cat_ID":6193,"category_count":79,"category_description":"<strong>Genetics is a branch of natural science that deals with heredity due to the transmission of genes, gene regulation, and gene manipulation.<\/strong>\r\n<ul>\r\n \t<li>Genetics is a connecting link between many disciplines like microbiology, biotechnology, medicine, and agriculture.<\/li>\r\n \t<li>Studies involving genes and chromosomes of living beings began quite late as it requires significant advances in the microscopy area.<\/li>\r\n \t<li>The influence of heredity and its application of cultivation and production improved organisms, however, had been recognized since ancient times.<\/li>\r\n \t<li>The study of genes and genetics began as a major concept after studies made by Mendel on pea plants. It was further strengthened and flourished by the works of Morgan.<\/li>\r\n \t<li>Eventually, genetics became a distinct area of study with the identification of genes and the study of genes at different levels, including their role in the cell, their regulation, and their expression.<\/li>\r\n \t<li>Initially, genetics was limited to understanding the concept and process of heredity via techniques like the formation of Punnet\u2019s square. With the development of techniques like X-ray diffraction, the structure of DNA, and the presence of genetic code were established. This paved the way for modern genetics.<\/li>\r\n \t<li>Modern genetics focuses on the chemical composition of structures found in genes like the DNA that influences the chemical reactions taking place in the cell.<\/li>\r\n \t<li>Gene expression is influenced by two major factors; the genetic composition and the influence of the environment.<\/li>\r\n \t<li>The influence of the environment on gene expression can be distinctly observed in green plants where the gene responsible for the formation of chlorophyll is only expressed in the presence of sunlight.<\/li>\r\n \t<li>\u00a0Genes, through the proteins they encode, determine how efficiently foods and chemicals are metabolized, how effectively toxins are detoxified, and even how vigorously infections are targeted.<\/li>\r\n \t<li>Processes like mutations are now a significant cause of major genetic diseases. The mutations might arise due to a complex combination of genetic, behavioral, and environmental factors.<\/li>\r\n<\/ul>","cat_name":"Genetics","category_nicename":"genetics","category_parent":0}]},"_links":{"self":[{"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/posts\/40839"}],"collection":[{"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/comments?post=40839"}],"version-history":[{"count":0,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/posts\/40839\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/media\/40838"}],"wp:attachment":[{"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/media?parent=40839"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/categories?post=40839"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/tags?post=40839"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}