{"id":42916,"date":"2025-06-29T12:00:12","date_gmt":"2025-06-29T12:00:12","guid":{"rendered":"https:\/\/gaviki.com\/blog\/?p=42916"},"modified":"2025-06-29T12:00:13","modified_gmt":"2025-06-29T12:00:13","slug":"a-cross-between-two-true-breeding-lines-one-with-dark-blue-flowers-and-one-with-bright-white-flowers-produces-f1-offspring-that-are-light-blue","status":"publish","type":"post","link":"https:\/\/gaviki.com\/blog\/a-cross-between-two-true-breeding-lines-one-with-dark-blue-flowers-and-one-with-bright-white-flowers-produces-f1-offspring-that-are-light-blue\/","title":{"rendered":"A cross between two true breeding lines one with dark-blue flowers and one with bright-white flowers produces F1 offspring that are light-blue"},"content":{"rendered":"\n<p>A cross between two true breeding lines one with dark-blue flowers and one with bright-white flowers produces F1 offspring that are light-blue. When the F1 progeny are selfed a 1:2:1 ratio of dark-blue to light-blue to bright-white flowers is observed. What genetic phenomenon is consistent with these results? a. incomplete dominance b. random mating c. codominance d. epistasis e. inbreeding depression<\/p>\n\n\n\n<p><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-vivid-cyan-blue-color\">The correct answer and explanation is:<\/mark><\/strong><\/p>\n\n\n\n<p>The correct answer is <strong>a. incomplete dominance<\/strong>.<\/p>\n\n\n\n<p>In this scenario, when two true-breeding lines (one with dark-blue flowers and one with bright-white flowers) are crossed, the F1 offspring exhibit light-blue flowers. This suggests that neither the dark-blue nor the bright-white allele is completely dominant over the other. Instead, they interact to produce an intermediate phenotype (light-blue flowers). This pattern is characteristic of <strong>incomplete dominance<\/strong>, where the heterozygous phenotype is a blend of the two homozygous phenotypes.<\/p>\n\n\n\n<p>When the F1 progeny are selfed, a 1:2:1 ratio of dark-blue to light-blue to bright-white flowers appears in the F2 generation. This is consistent with Mendelian inheritance for a single gene with incomplete dominance. The alleles involved in incomplete dominance are typically represented as follows:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>D<\/strong> for dark-blue (dominant)<\/li>\n\n\n\n<li><strong>W<\/strong> for bright-white (recessive)<\/li>\n<\/ul>\n\n\n\n<p>In the F1 generation, the offspring inherit one <strong>D<\/strong> allele from one parent and one <strong>W<\/strong> allele from the other parent, resulting in a <strong>DW<\/strong> genotype, which produces the light-blue color. When these F1 individuals are self-crossed (DW x DW), the possible genotypes in the F2 generation are:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>DD<\/strong> (dark-blue flowers)<\/li>\n\n\n\n<li><strong>DW<\/strong> (light-blue flowers)<\/li>\n\n\n\n<li><strong>WW<\/strong> (bright-white flowers)<\/li>\n<\/ul>\n\n\n\n<p>This results in a 1:2:1 phenotypic ratio (1 dark-blue: 2 light-blue: 1 bright-white), which is a typical outcome of incomplete dominance. The key feature of incomplete dominance is that the heterozygous offspring display an intermediate phenotype, not resembling either of the parental phenotypes exactly.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>A cross between two true breeding lines one with dark-blue flowers and one with bright-white flowers produces F1 offspring that are light-blue. When the F1 progeny are selfed a 1:2:1 ratio of dark-blue to light-blue to bright-white flowers is observed. What genetic phenomenon is consistent with these results? a. incomplete dominance b. random mating c. [&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-42916","post","type-post","status-publish","format-standard","hentry","category-quiz-questions"],"_links":{"self":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/42916","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=42916"}],"version-history":[{"count":1,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/42916\/revisions"}],"predecessor-version":[{"id":42921,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/42916\/revisions\/42921"}],"wp:attachment":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/media?parent=42916"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/categories?post=42916"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/tags?post=42916"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}