{"id":201688,"date":"2025-03-15T21:07:52","date_gmt":"2025-03-15T21:07:52","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=201688"},"modified":"2025-03-15T21:07:54","modified_gmt":"2025-03-15T21:07:54","slug":"an-aquatic-arthropod-called-a-cyclops-has-antennae-that-are-either-smooth-or-barbed","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/03\/15\/an-aquatic-arthropod-called-a-cyclops-has-antennae-that-are-either-smooth-or-barbed\/","title":{"rendered":"An aquatic arthropod called a Cyclops has antennae that are either smooth or barbed"},"content":{"rendered":"\n

An aquatic arthropod called a Cyclops has antennae that are either smooth or barbed. The allele for barbs is dominant. In the same organism, resistance to pesticides is a recessive trait. Make a “key” to show all the possible genotypes (and phenotypes) of this organism. Use the rabbit key to help you if you’re lost.<\/p>\n\n\n\n

Key:<\/p>\n\n\n\n

The correct answer and explanation is :<\/strong><\/mark><\/p>\n\n\n\n

Sure! To create a key for the Cyclops organism with two traits, we need to break down the genetic possibilities based on the dominant and recessive alleles. The two traits in question are:<\/p>\n\n\n\n

    \n
  1. Antennae type<\/strong> (smooth or barbed)<\/li>\n<\/ol>\n\n\n\n
      \n
    • Barbed antennae<\/strong> is the dominant trait (B).<\/li>\n\n\n\n
    • Smooth antennae<\/strong> is the recessive trait (b).<\/li>\n<\/ul>\n\n\n\n
        \n
      1. Resistance to pesticides<\/strong> (resistant or susceptible)<\/li>\n<\/ol>\n\n\n\n
          \n
        • Resistance to pesticides<\/strong> is recessive (r), so an organism must have two copies of the recessive allele (rr) to be resistant.<\/li>\n\n\n\n
        • Susceptibility to pesticides<\/strong> is the dominant trait (R), so the organism can either have one dominant allele (Rr) or two dominant alleles (RR) to be susceptible.<\/li>\n<\/ul>\n\n\n\n

          Key:<\/h3>\n\n\n\n
            \n
          • B<\/strong> = Barbed antennae (dominant)<\/li>\n\n\n\n
          • b<\/strong> = Smooth antennae (recessive)<\/li>\n\n\n\n
          • R<\/strong> = Susceptible to pesticides (dominant)<\/li>\n\n\n\n
          • r<\/strong> = Resistant to pesticides (recessive)<\/li>\n<\/ul>\n\n\n\n

            Step 1: List the possible combinations of alleles for each trait.<\/h3>\n\n\n\n
              \n
            • For antennae:<\/li>\n\n\n\n
            • BB<\/strong> (Barbed)<\/li>\n\n\n\n
            • Bb<\/strong> (Barbed)<\/li>\n\n\n\n
            • bb<\/strong> (Smooth)<\/li>\n\n\n\n
            • For pesticide resistance:<\/li>\n\n\n\n
            • RR<\/strong> (Susceptible)<\/li>\n\n\n\n
            • Rr<\/strong> (Susceptible)<\/li>\n\n\n\n
            • rr<\/strong> (Resistant)<\/li>\n<\/ul>\n\n\n\n

              Step 2: Combine the alleles for both traits.<\/h3>\n\n\n\n

              The Cyclops organism has two traits, so we will combine the possible alleles for antennae and pesticide resistance:<\/p>\n\n\n\n

                \n
              1. BBRR<\/strong> – Barbed antennae, Susceptible to pesticides<\/li>\n\n\n\n
              2. BBRr<\/strong> – Barbed antennae, Susceptible to pesticides<\/li>\n\n\n\n
              3. BbRR<\/strong> – Barbed antennae, Susceptible to pesticides<\/li>\n\n\n\n
              4. BbRr<\/strong> – Barbed antennae, Susceptible to pesticides<\/li>\n\n\n\n
              5. bbRR<\/strong> – Smooth antennae, Susceptible to pesticides<\/li>\n\n\n\n
              6. bbRr<\/strong> – Smooth antennae, Susceptible to pesticides<\/li>\n\n\n\n
              7. BBrr<\/strong> – Barbed antennae, Resistant to pesticides<\/li>\n\n\n\n
              8. Bbr<\/strong> – Barbed antennae, Resistant to pesticides<\/li>\n\n\n\n
              9. bbrr<\/strong> – Smooth antennae, Resistant to pesticides<\/li>\n<\/ol>\n\n\n\n

                Step 3: Write the phenotypes based on the alleles.<\/h3>\n\n\n\n
                  \n
                • Barbed antennae, Susceptible to pesticides<\/strong>: Any genotype with at least one B<\/strong> and either R<\/strong> or Rr<\/strong> (BBRR, BBRr, BbRR, BbRr).<\/li>\n\n\n\n
                • Smooth antennae, Susceptible to pesticides<\/strong>: bb<\/strong> and either RR<\/strong> or Rr<\/strong> (bbRR, bbRr).<\/li>\n\n\n\n
                • Barbed antennae, Resistant to pesticides<\/strong>: Any genotype with at least one B<\/strong> and rr<\/strong> (BBrr, Bbr).<\/li>\n\n\n\n
                • Smooth antennae, Resistant to pesticides<\/strong>: bb<\/strong> and rr<\/strong> (bbrr).<\/li>\n<\/ul>\n\n\n\n

                  Explanation:<\/h3>\n\n\n\n
                    \n
                  • Dominant vs. Recessive<\/strong>: The barbed antennae<\/strong> trait is dominant (B), meaning the organism only needs one copy of the dominant allele to have barbed antennae. For resistance to pesticides<\/strong>, however, the trait is recessive (r), so the organism must have two copies of the recessive allele (rr<\/strong>) to be resistant. If it has at least one dominant allele (R), it will be susceptible to pesticides.<\/li>\n\n\n\n
                  • Genotype vs. Phenotype<\/strong>: The genotype refers to the specific alleles an organism has (e.g., BBRR<\/strong>), while the phenotype describes the observable traits (e.g., barbed antennae and susceptible to pesticides).<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"

                    An aquatic arthropod called a Cyclops has antennae that are either smooth or barbed. The allele for barbs is dominant. In the same organism, resistance to pesticides is a recessive trait. Make a “key” to show all the possible genotypes (and phenotypes) of this organism. Use the rabbit key to help you if you’re lost. […]<\/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-201688","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/201688","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=201688"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/201688\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=201688"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=201688"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=201688"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}