{"id":87099,"date":"2025-06-01T04:28:07","date_gmt":"2025-06-01T04:28:07","guid":{"rendered":"https:\/\/exam.pscnotes.com\/mcq\/?p=87099"},"modified":"2025-06-01T04:28:07","modified_gmt":"2025-06-01T04:28:07","slug":"nitrogen-cycle-is-one-of-the-most-important-microorganisms-mediated-ch","status":"publish","type":"post","link":"https:\/\/exam.pscnotes.com\/mcq\/nitrogen-cycle-is-one-of-the-most-important-microorganisms-mediated-ch\/","title":{"rendered":"Nitrogen cycle is one of the most important microorganisms-mediated ch"},"content":{"rendered":"<p>Nitrogen cycle is one of the most important microorganisms-mediated chemical reactions in aquatic and soil environments. In this context consider the following statements :<\/p>\n<ul>\n<li>1. Nitrogen fixation is the process of oxidising NH\u2083 to NO\u2083\u207b.<\/li>\n<li>2. Nitrification process causes reduction of NO\u2083 and NO\u2082\u207b to NO\u2082, followed by recycling of N\u2082 to the atmosphere.<\/li>\n<li>3. Denitrification converts molecular N\u2082 into a fixed form as an organic nitrogen.<\/li>\n<\/ul>\n<p>How many of the statements given above is\/are correct ?<\/p>\n<p>[amp_mcq option1=&#8221;1&#8243; option2=&#8221;2&#8243; option3=&#8221;3&#8243; option4=&#8221;None&#8221; correct=&#8221;option4&#8243;]<\/p>\n<div class=\"psc-box-pyq-exam-year-detail\">\n<div class=\"pyq-exam\">\n<div class=\"psc-heading\">This question was previously asked in<\/div>\n<div class=\"psc-title line-ellipsis\">UPSC Geoscientist &#8211; 2024<\/div>\n<\/div>\n<div class=\"pyq-exam-psc-buttons\"><a href=\"\/pyq\/pyq-upsc-geoscientist-2024.pdf\" target=\"_blank\" class=\"psc-pdf-button\" rel=\"noopener\">Download PDF<\/a><a href=\"\/pyq-upsc-geoscientist-2024\" target=\"_blank\" class=\"psc-attempt-button\" rel=\"noopener\">Attempt Online<\/a><\/div>\n<\/div>\n<section id=\"pyq-correct-answer\">\nCorrect Answer: D<br \/>\n<\/section>\n<section id=\"pyq-key-points\">\n&#8211; Statement 1 is incorrect: Nitrogen fixation is the process where atmospheric nitrogen (N\u2082) is converted into ammonia (NH\u2083) or other nitrogenous compounds. The process described (oxidising NH\u2083 to NO\u2083\u207b) is nitrification, which involves the oxidation of ammonia first to nitrite (NO\u2082\u207b) and then to nitrate (NO\u2083\u207b).<br \/>\n&#8211; Statement 2 is incorrect: The process described (reduction of NO\u2083\u207b and NO\u2082\u207b to NO\u2082, followed by recycling of N\u2082 to the atmosphere) is denitrification, which is the conversion of nitrates and nitrites back into nitrogen gas (N\u2082) under anaerobic conditions. Nitrification is the oxidation of ammonia compounds.<br \/>\n&#8211; Statement 3 is incorrect: Denitrification converts fixed nitrogen (like nitrates and nitrites) back into atmospheric molecular nitrogen (N\u2082). The process that converts molecular N\u2082 into a fixed form as organic nitrogen (via ammonia) is nitrogen fixation.<br \/>\n<\/section>\n<section id=\"pyq-additional-information\">\nThe nitrogen cycle is a complex biogeochemical cycle involving various microbial processes. The main processes are nitrogen fixation (N\u2082 to NH\u2083), nitrification (NH\u2083 to NO\u2082\u207b to NO\u2083\u207b), assimilation (uptake of nitrogen by organisms), ammonification (organic nitrogen to NH\u2083), and denitrification (NO\u2083\u207b to N\u2082). Each process is crucial for the availability and cycling of nitrogen in ecosystems.<br \/>\n<\/section>\n","protected":false},"excerpt":{"rendered":"<p>Nitrogen cycle is one of the most important microorganisms-mediated chemical reactions in aquatic and soil environments. In this context consider the following statements : 1. Nitrogen fixation is the process of oxidising NH\u2083 to NO\u2083\u207b. 2. Nitrification process causes reduction of NO\u2083 and NO\u2082\u207b to NO\u2082, followed by recycling of N\u2082 to the atmosphere. 3. &#8230; <\/p>\n<p class=\"read-more-container\"><a title=\"Nitrogen cycle is one of the most important microorganisms-mediated ch\" class=\"read-more button\" href=\"https:\/\/exam.pscnotes.com\/mcq\/nitrogen-cycle-is-one-of-the-most-important-microorganisms-mediated-ch\/#more-87099\">Detailed Solution<span class=\"screen-reader-text\">Nitrogen cycle is one of the most important microorganisms-mediated ch<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1091],"tags":[1103,1367,1136],"class_list":["post-87099","post","type-post","status-publish","format-standard","hentry","category-upsc-geoscientist","tag-1103","tag-ecology","tag-environment-and-ecology","no-featured-image-padding"],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v22.2 (Yoast SEO v23.3) - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>Nitrogen cycle is one of the most important microorganisms-mediated ch<\/title>\n<meta name=\"description\" content=\"Correct Answer: D - Statement 1 is incorrect: Nitrogen fixation is the process where atmospheric nitrogen (N\u2082) is converted into ammonia (NH\u2083) or other nitrogenous compounds. The process described (oxidising NH\u2083 to NO\u2083\u207b) is nitrification, which involves the oxidation of ammonia first to nitrite (NO\u2082\u207b) and then to nitrate (NO\u2083\u207b). - Statement 2 is incorrect: The process described (reduction of NO\u2083\u207b and NO\u2082\u207b to NO\u2082, followed by recycling of N\u2082 to the atmosphere) is denitrification, which is the conversion of nitrates and nitrites back into nitrogen gas (N\u2082) under anaerobic conditions. Nitrification is the oxidation of ammonia compounds. - Statement 3 is incorrect: Denitrification converts fixed nitrogen (like nitrates and nitrites) back into atmospheric molecular nitrogen (N\u2082). The process that converts molecular N\u2082 into a fixed form as organic nitrogen (via ammonia) is nitrogen fixation.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/exam.pscnotes.com\/mcq\/nitrogen-cycle-is-one-of-the-most-important-microorganisms-mediated-ch\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Nitrogen cycle is one of the most important microorganisms-mediated ch\" \/>\n<meta property=\"og:description\" content=\"Correct Answer: D - Statement 1 is incorrect: Nitrogen fixation is the process where atmospheric nitrogen (N\u2082) is converted into ammonia (NH\u2083) or other nitrogenous compounds. The process described (oxidising NH\u2083 to NO\u2083\u207b) is nitrification, which involves the oxidation of ammonia first to nitrite (NO\u2082\u207b) and then to nitrate (NO\u2083\u207b). - Statement 2 is incorrect: The process described (reduction of NO\u2083\u207b and NO\u2082\u207b to NO\u2082, followed by recycling of N\u2082 to the atmosphere) is denitrification, which is the conversion of nitrates and nitrites back into nitrogen gas (N\u2082) under anaerobic conditions. Nitrification is the oxidation of ammonia compounds. - Statement 3 is incorrect: Denitrification converts fixed nitrogen (like nitrates and nitrites) back into atmospheric molecular nitrogen (N\u2082). The process that converts molecular N\u2082 into a fixed form as organic nitrogen (via ammonia) is nitrogen fixation.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/exam.pscnotes.com\/mcq\/nitrogen-cycle-is-one-of-the-most-important-microorganisms-mediated-ch\/\" \/>\n<meta property=\"og:site_name\" content=\"MCQ and Quiz for Exams\" \/>\n<meta property=\"article:published_time\" content=\"2025-06-01T04:28:07+00:00\" \/>\n<meta name=\"author\" content=\"rawan239\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"rawan239\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"1 minute\" \/>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"Nitrogen cycle is one of the most important microorganisms-mediated ch","description":"Correct Answer: D - Statement 1 is incorrect: Nitrogen fixation is the process where atmospheric nitrogen (N\u2082) is converted into ammonia (NH\u2083) or other nitrogenous compounds. The process described (oxidising NH\u2083 to NO\u2083\u207b) is nitrification, which involves the oxidation of ammonia first to nitrite (NO\u2082\u207b) and then to nitrate (NO\u2083\u207b). - Statement 2 is incorrect: The process described (reduction of NO\u2083\u207b and NO\u2082\u207b to NO\u2082, followed by recycling of N\u2082 to the atmosphere) is denitrification, which is the conversion of nitrates and nitrites back into nitrogen gas (N\u2082) under anaerobic conditions. Nitrification is the oxidation of ammonia compounds. - Statement 3 is incorrect: Denitrification converts fixed nitrogen (like nitrates and nitrites) back into atmospheric molecular nitrogen (N\u2082). The process that converts molecular N\u2082 into a fixed form as organic nitrogen (via ammonia) is nitrogen fixation.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/exam.pscnotes.com\/mcq\/nitrogen-cycle-is-one-of-the-most-important-microorganisms-mediated-ch\/","og_locale":"en_US","og_type":"article","og_title":"Nitrogen cycle is one of the most important microorganisms-mediated ch","og_description":"Correct Answer: D - Statement 1 is incorrect: Nitrogen fixation is the process where atmospheric nitrogen (N\u2082) is converted into ammonia (NH\u2083) or other nitrogenous compounds. The process described (oxidising NH\u2083 to NO\u2083\u207b) is nitrification, which involves the oxidation of ammonia first to nitrite (NO\u2082\u207b) and then to nitrate (NO\u2083\u207b). - Statement 2 is incorrect: The process described (reduction of NO\u2083\u207b and NO\u2082\u207b to NO\u2082, followed by recycling of N\u2082 to the atmosphere) is denitrification, which is the conversion of nitrates and nitrites back into nitrogen gas (N\u2082) under anaerobic conditions. Nitrification is the oxidation of ammonia compounds. - Statement 3 is incorrect: Denitrification converts fixed nitrogen (like nitrates and nitrites) back into atmospheric molecular nitrogen (N\u2082). The process that converts molecular N\u2082 into a fixed form as organic nitrogen (via ammonia) is nitrogen fixation.","og_url":"https:\/\/exam.pscnotes.com\/mcq\/nitrogen-cycle-is-one-of-the-most-important-microorganisms-mediated-ch\/","og_site_name":"MCQ and Quiz for Exams","article_published_time":"2025-06-01T04:28:07+00:00","author":"rawan239","twitter_card":"summary_large_image","twitter_misc":{"Written by":"rawan239","Est. reading time":"1 minute"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/exam.pscnotes.com\/mcq\/nitrogen-cycle-is-one-of-the-most-important-microorganisms-mediated-ch\/","url":"https:\/\/exam.pscnotes.com\/mcq\/nitrogen-cycle-is-one-of-the-most-important-microorganisms-mediated-ch\/","name":"Nitrogen cycle is one of the most important microorganisms-mediated ch","isPartOf":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#website"},"datePublished":"2025-06-01T04:28:07+00:00","dateModified":"2025-06-01T04:28:07+00:00","author":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/5807dafeb27d2ec82344d6cbd6c3d209"},"description":"Correct Answer: D - Statement 1 is incorrect: Nitrogen fixation is the process where atmospheric nitrogen (N\u2082) is converted into ammonia (NH\u2083) or other nitrogenous compounds. The process described (oxidising NH\u2083 to NO\u2083\u207b) is nitrification, which involves the oxidation of ammonia first to nitrite (NO\u2082\u207b) and then to nitrate (NO\u2083\u207b). - Statement 2 is incorrect: The process described (reduction of NO\u2083\u207b and NO\u2082\u207b to NO\u2082, followed by recycling of N\u2082 to the atmosphere) is denitrification, which is the conversion of nitrates and nitrites back into nitrogen gas (N\u2082) under anaerobic conditions. Nitrification is the oxidation of ammonia compounds. - Statement 3 is incorrect: Denitrification converts fixed nitrogen (like nitrates and nitrites) back into atmospheric molecular nitrogen (N\u2082). The process that converts molecular N\u2082 into a fixed form as organic nitrogen (via ammonia) is nitrogen fixation.","breadcrumb":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/nitrogen-cycle-is-one-of-the-most-important-microorganisms-mediated-ch\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/exam.pscnotes.com\/mcq\/nitrogen-cycle-is-one-of-the-most-important-microorganisms-mediated-ch\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/exam.pscnotes.com\/mcq\/nitrogen-cycle-is-one-of-the-most-important-microorganisms-mediated-ch\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/exam.pscnotes.com\/mcq\/"},{"@type":"ListItem","position":2,"name":"UPSC Geoscientist","item":"https:\/\/exam.pscnotes.com\/mcq\/category\/upsc-geoscientist\/"},{"@type":"ListItem","position":3,"name":"Nitrogen cycle is one of the most important microorganisms-mediated ch"}]},{"@type":"WebSite","@id":"https:\/\/exam.pscnotes.com\/mcq\/#website","url":"https:\/\/exam.pscnotes.com\/mcq\/","name":"MCQ and Quiz for Exams","description":"","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/exam.pscnotes.com\/mcq\/?s={search_term_string}"},"query-input":"required name=search_term_string"}],"inLanguage":"en-US"},{"@type":"Person","@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/5807dafeb27d2ec82344d6cbd6c3d209","name":"rawan239","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/761a7274f9cce048fa5b921221e7934820d74514df93ef195a9d22af0c1c9001?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/761a7274f9cce048fa5b921221e7934820d74514df93ef195a9d22af0c1c9001?s=96&d=mm&r=g","caption":"rawan239"},"sameAs":["https:\/\/exam.pscnotes.com"],"url":"https:\/\/exam.pscnotes.com\/mcq\/author\/rawan239\/"}]}},"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts\/87099","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/comments?post=87099"}],"version-history":[{"count":0,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts\/87099\/revisions"}],"wp:attachment":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/media?parent=87099"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/categories?post=87099"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/tags?post=87099"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}