{"id":266630,"date":"2025-07-23T06:10:18","date_gmt":"2025-07-23T06:10:18","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=266630"},"modified":"2025-07-23T06:10:21","modified_gmt":"2025-07-23T06:10:21","slug":"which-of-the-following-statements-is-not-true-regarding-an-hfr-x-f-bacterial-cross","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/07\/23\/which-of-the-following-statements-is-not-true-regarding-an-hfr-x-f-bacterial-cross\/","title":{"rendered":"Which of the following statements is NOT TRUE regarding an Hfr X F bacterial cross"},"content":{"rendered":"\n

Which of the following statements is NOT TRUE regarding an Hfr X F bacterial cross? A The recipient usually remains F B. Large segments of the donor Hfr chromosome can be transferred into the F- cell: C. The F chromosome can undergo recombination with piece of the donor chromosome D. The donor cell becomes P E. Hfr X F crosses can be used t0 order bacterial genes on a linear map:<\/p>\n\n\n\n

The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n

The statement that is NOT TRUE<\/strong> regarding an Hfr X F bacterial cross<\/strong> is:<\/p>\n\n\n\n

D. The donor cell becomes F.<\/strong><\/p>\n\n\n\n

Explanation:<\/h3>\n\n\n\n

In an Hfr (High frequency of recombination) X F (Fertility factor) bacterial cross, the key steps involve the transfer of genetic material from an Hfr cell to an F- (recipient) cell. Here’s why each statement is true or false:<\/p>\n\n\n\n

A. The recipient usually remains F.<\/strong><\/p>\n\n\n\n

    \n
  • True.<\/strong> The F- cell, which initially lacks the F plasmid, typically remains F- after the cross. The transferred genetic material does not usually include the entire F plasmid, so the recipient cell does not become F+.<\/li>\n<\/ul>\n\n\n\n

    B. Large segments of the donor Hfr chromosome can be transferred into the F- cell.<\/strong><\/p>\n\n\n\n

      \n
    • True.<\/strong> In an Hfr X F cross, the F plasmid is integrated into the bacterial chromosome of the donor Hfr cell. During conjugation, large segments of the donor’s chromosome (which includes the F plasmid) can be transferred to the recipient F- cell. The process starts from the origin of the F plasmid and can extend to distant parts of the donor chromosome.<\/li>\n<\/ul>\n\n\n\n

      C. The F chromosome can undergo recombination with a piece of the donor chromosome.<\/strong><\/p>\n\n\n\n

        \n
      • True.<\/strong> The transferred DNA can undergo recombination with the recipient’s chromosome. This is an essential aspect of the Hfr X F cross because it allows the mapping of bacterial genes based on how frequently they recombine with the recipient chromosome.<\/li>\n<\/ul>\n\n\n\n

        D. The donor cell becomes F.<\/strong><\/p>\n\n\n\n

          \n
        • False.<\/strong> In an Hfr X F cross, the donor cell does not<\/strong> become F+. The donor (Hfr) retains its integrated F plasmid in the chromosome. The F plasmid is not usually transferred in its entirety, so the donor remains Hfr, not F+.<\/li>\n<\/ul>\n\n\n\n

          E. Hfr X F crosses can be used to order bacterial genes on a linear map.<\/strong><\/p>\n\n\n\n

            \n
          • True.<\/strong> Hfr X F crosses are crucial for creating genetic maps. By measuring the time at which different genes are transferred to the recipient cell, researchers can create a linear map of bacterial genes.<\/li>\n<\/ul>\n\n\n\n

            In summary, the donor does not<\/strong> become F in an Hfr X F cross. Therefore, D<\/strong> is the incorrect statement.<\/p>\n\n\n\n

            \"\"<\/figure>\n","protected":false},"excerpt":{"rendered":"

            Which of the following statements is NOT TRUE regarding an Hfr X F bacterial cross? A The recipient usually remains F B. Large segments of the donor Hfr chromosome can be transferred into the F- cell: C. The F chromosome can undergo recombination with piece of the donor chromosome D. The donor cell becomes P […]<\/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-266630","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/266630","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=266630"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/266630\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=266630"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=266630"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=266630"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}