{"id":216169,"date":"2025-05-18T20:06:39","date_gmt":"2025-05-18T20:06:39","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=216169"},"modified":"2025-05-18T20:06:42","modified_gmt":"2025-05-18T20:06:42","slug":"a-tall-pea-plant-with-axial-flowers-was-crossed-to-a-dwarf-plant-with-terminal-flowers","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/05\/18\/a-tall-pea-plant-with-axial-flowers-was-crossed-to-a-dwarf-plant-with-terminal-flowers\/","title":{"rendered":"A tall pea plant with axial flowers was crossed to a dwarf plant with terminal flowers."},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">A tall pea plant with axial flowers was crossed to a dwarf plant with terminal flowers. Tall plants and axial flowers are dominant traits. The following offspring were obtained: 27 tall, axial flowers; 23 tall, terminal flowers; 28 dwarf, axial flowers; and 25 dwarf, terminal flowers. What are the genotypes of the parents?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-1-color\">The Correct Answer and Explanation is<\/mark><\/strong>:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Correct Answer:<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The genotypes of the parents are:<br><strong>TtAa \u00d7 ttaa<\/strong><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Explanation:<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">This genetics problem involves <strong>dihybrid inheritance<\/strong>, where we are tracking two traits:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Plant height<\/strong>:<\/li>\n\n\n\n<li>Tall (T) is dominant<\/li>\n\n\n\n<li>Dwarf (t) is recessive<\/li>\n\n\n\n<li><strong>Flower position<\/strong>:<\/li>\n\n\n\n<li>Axial (A) is dominant<\/li>\n\n\n\n<li>Terminal (a) is recessive<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The observed offspring are:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>27 tall, axial<\/li>\n\n\n\n<li>23 tall, terminal<\/li>\n\n\n\n<li>28 dwarf, axial<\/li>\n\n\n\n<li>25 dwarf, terminal<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">These numbers are roughly equal, suggesting a <strong>1:1:1:1 phenotypic ratio<\/strong>. This pattern is a classic outcome of a <strong>dihybrid test cross<\/strong>, which is used to determine the genotype of an individual with dominant traits.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Let\u2019s break it down:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Step 1: Determine phenotype and possible genotype of parents<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>One parent is <strong>tall with axial flowers<\/strong> \u2014 since these are dominant traits, the genotype <strong>could<\/strong> be either homozygous (TTAA) or heterozygous (TtAa).<\/li>\n\n\n\n<li>The other parent is <strong>dwarf with terminal flowers<\/strong>, which are <strong>recessive traits<\/strong>, so the genotype must be <strong>ttaa<\/strong>.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">We test which genotype of the dominant parent (tall with axial flowers) could produce the 1:1:1:1 offspring ratio when crossed with ttaa.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Step 2: Try TtAa \u00d7 ttaa<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Gametes from <strong>TtAa<\/strong> = TA, Ta, tA, ta<br>Gametes from <strong>ttaa<\/strong> = ta (only one type)<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Crossing them yields:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>TA \u00d7 ta \u2192 TtAa (Tall, Axial)<\/li>\n\n\n\n<li>Ta \u00d7 ta \u2192 Ttaa (Tall, Terminal)<\/li>\n\n\n\n<li>tA \u00d7 ta \u2192 ttAa (Dwarf, Axial)<\/li>\n\n\n\n<li>ta \u00d7 ta \u2192 ttaa (Dwarf, Terminal)<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Each genotype occurs in equal proportion (1:1:1:1), and that exactly matches the observed data:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>27 tall, axial<\/li>\n\n\n\n<li>23 tall, terminal<\/li>\n\n\n\n<li>28 dwarf, axial<\/li>\n\n\n\n<li>25 dwarf, terminal<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Conclusion:<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">This confirms that the <strong>dominant parent is heterozygous for both traits (TtAa)<\/strong>, and the recessive parent is <strong>ttaa<\/strong>.<br>So, the genotypes of the parents are:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\ud83d\udc49 <strong>TtAa \u00d7 ttaa<\/strong>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>A tall pea plant with axial flowers was crossed to a dwarf plant with terminal flowers. Tall plants and axial flowers are dominant traits. The following offspring were obtained: 27 tall, axial flowers; 23 tall, terminal flowers; 28 dwarf, axial flowers; and 25 dwarf, terminal flowers. What are the genotypes of the parents? The Correct [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[25],"tags":[],"class_list":["post-216169","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/216169","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/comments?post=216169"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/216169\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=216169"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=216169"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=216169"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}