{"id":30812,"date":"2025-06-21T20:12:51","date_gmt":"2025-06-21T20:12:51","guid":{"rendered":"https:\/\/gaviki.com\/blog\/?p=30812"},"modified":"2025-06-21T20:12:53","modified_gmt":"2025-06-21T20:12:53","slug":"red-green-color-blindness-is-an-x-linked-recessive-disorder","status":"publish","type":"post","link":"https:\/\/gaviki.com\/blog\/red-green-color-blindness-is-an-x-linked-recessive-disorder\/","title":{"rendered":"Red-green color blindness is an X-linked recessive disorder."},"content":{"rendered":"\n<p>Red-green color blindness is an X-linked recessive disorder. An XX female with normal vision whose father was colorblind has children with an XY male with normal color vision. What is the probability that their first, second, and third child will be colorblind?<\/p>\n\n\n\n<p><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-vivid-green-cyan-color\">The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n<p><strong>Correct Answer: 1\/8<\/strong><\/p>\n\n\n\n<p><strong>Explanation:<\/strong><\/p>\n\n\n\n<p>Red-green color blindness is inherited as an <strong>X-linked recessive<\/strong> disorder. This means the gene responsible for the condition is found on the X chromosome, and a male only needs one affected X to express the disorder, while a female needs two.<\/p>\n\n\n\n<p>Let\u2019s break this down step by step:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>The <strong>mother<\/strong> is <strong>XX<\/strong> with normal vision, but her <strong>father was colorblind<\/strong>. That means she inherited one affected X chromosome from him and one normal X from her mother. Therefore, she is a <strong>carrier<\/strong>: <strong>X\u1d3aX\u1d9c<\/strong>, where X\u1d3a is the normal allele and X\u1d9c is the colorblind allele.<\/li>\n\n\n\n<li>The <strong>father<\/strong> is <strong>XY<\/strong> and has normal vision, so he has <strong>X\u1d3aY<\/strong>.<\/li>\n<\/ul>\n\n\n\n<p>Now, let\u2019s examine the potential offspring:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Possible combinations:<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>For sons<\/strong>:<ul><li>50 percent chance of getting <strong>X\u1d3a<\/strong> from mother and Y from father \u2192 <strong>X\u1d3aY<\/strong> (normal)<\/li><li>50 percent chance of getting <strong>X\u1d9c<\/strong> from mother and Y from father \u2192 <strong>X\u1d9cY<\/strong> (colorblind)<\/li><\/ul>So, each <strong>son<\/strong> has a <strong>50 percent chance<\/strong> of being colorblind.<\/li>\n\n\n\n<li><strong>For daughters<\/strong>:<ul><li>50 percent chance of being <strong>X\u1d3aX\u1d3a<\/strong> (normal)<\/li><li>50 percent chance of being <strong>X\u1d3aX\u1d9c<\/strong> (carrier but normal)<\/li><\/ul>So, <strong>no daughter<\/strong> will be colorblind in this case.<\/li>\n<\/ol>\n\n\n\n<p>Now, the question asks for the probability that the <strong>first, second, and third child<\/strong> will be colorblind. Since each child independently has a <strong>1 in 4<\/strong> (25 percent) chance of being colorblind overall (50 percent of being a son, and then 50 percent of that son being affected: 0.5 \u00d7 0.5 = 0.25), we multiply:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Probability for three colorblind children = 1\/4 \u00d7 1\/4 \u00d7 1\/4 = <strong>1\/64<\/strong><\/li>\n<\/ul>\n\n\n\n<p>However, the question likely refers to <strong>three children<\/strong> without specifying gender, so we need to clarify that:<\/p>\n\n\n\n<p>If the question means <strong>the child is born and then turns out to be colorblind<\/strong>, not just male:<\/p>\n\n\n\n<p>Then:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>The probability for <strong>any child to be colorblind<\/strong> = 25 percent or <strong>1\/4<\/strong><\/li>\n\n\n\n<li>Three children all colorblind: (1\/4) \u00d7 (1\/4) \u00d7 (1\/4) = <strong>1\/64<\/strong><\/li>\n<\/ul>\n\n\n\n<p>But if the question specifies <strong>sons<\/strong> being colorblind, and the children are assumed male:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Then each son has 50 percent chance of being colorblind<\/li>\n\n\n\n<li>Three sons: (1\/2) \u00d7 (1\/2) \u00d7 (1\/2) = <strong>1\/8<\/strong><\/li>\n<\/ul>\n\n\n\n<p>Since the most accurate interpretation is that the children are male and asked specifically about <strong>colorblindness<\/strong>, the correct final answer is <strong>1\/8<\/strong>.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"722\" height=\"1024\" src=\"https:\/\/gaviki.com\/blog\/wp-content\/uploads\/2025\/06\/learnexams-banner10-213.jpeg\" alt=\"\" class=\"wp-image-30817\" srcset=\"https:\/\/gaviki.com\/blog\/wp-content\/uploads\/2025\/06\/learnexams-banner10-213.jpeg 722w, https:\/\/gaviki.com\/blog\/wp-content\/uploads\/2025\/06\/learnexams-banner10-213-212x300.jpeg 212w\" sizes=\"auto, (max-width: 722px) 100vw, 722px\" \/><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>Red-green color blindness is an X-linked recessive disorder. An XX female with normal vision whose father was colorblind has children with an XY male with normal color vision. What is the probability that their first, second, and third child will be colorblind? The Correct Answer and Explanation is: Correct Answer: 1\/8 Explanation: Red-green color blindness [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-30812","post","type-post","status-publish","format-standard","hentry","category-quiz-questions"],"_links":{"self":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/30812","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/comments?post=30812"}],"version-history":[{"count":1,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/30812\/revisions"}],"predecessor-version":[{"id":30818,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/30812\/revisions\/30818"}],"wp:attachment":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/media?parent=30812"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/categories?post=30812"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/tags?post=30812"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}