{"id":90174,"date":"2025-06-01T10:22:16","date_gmt":"2025-06-01T10:22:16","guid":{"rendered":"https:\/\/exam.pscnotes.com\/mcq\/?p=90174"},"modified":"2025-06-01T10:22:16","modified_gmt":"2025-06-01T10:22:16","slug":"which-of-the-following-are-the-necessary-conditions-for-the-growth-of","status":"publish","type":"post","link":"https:\/\/exam.pscnotes.com\/mcq\/which-of-the-following-are-the-necessary-conditions-for-the-growth-of\/","title":{"rendered":"Which of the following are the necessary conditions for the growth of"},"content":{"rendered":"<p>Which of the following are the necessary conditions for the growth of coral reefs?<\/p>\n<ul>\n<li>1. Photic conditions<\/li>\n<li>2. Clean and sediment free water<\/li>\n<li>3. Sea salinity of 6%<\/li>\n<li>4. Tropical sea water with temperature of 20\u00b0C to 21\u00b0C<\/li>\n<\/ul>\n<p>Select the correct answer using the code given below :<\/p>\n<p>[amp_mcq option1=&#8221;1, 2 and 4 only&#8221; option2=&#8221;2 and 4 only&#8221; option3=&#8221;1 and 3 only&#8221; option4=&#8221;1, 2, 3 and 4&#8243; correct=&#8221;option1&#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 CAPF &#8211; 2017<\/div>\n<\/div>\n<div class=\"pyq-exam-psc-buttons\"><a href=\"\/pyq\/pyq-upsc-capf-2017.pdf\" target=\"_blank\" class=\"psc-pdf-button\" rel=\"noopener\">Download PDF<\/a><a href=\"\/pyq-upsc-capf-2017\" target=\"_blank\" class=\"psc-attempt-button\" rel=\"noopener\">Attempt Online<\/a><\/div>\n<\/div>\n<section id=\"pyq-correct-answer\">\nThe correct answer is A) 1, 2 and 4 only.<br \/>\n<\/section>\n<section id=\"pyq-key-points\">\nCoral reefs are complex ecosystems built by tiny marine animals called coral polyps. Their growth depends on specific environmental conditions:<br \/>\n1.  **Photic conditions:** Corals have a symbiotic relationship with photosynthetic algae called zooxanthellae living in their tissues. These algae require sunlight for photosynthesis, which provides energy to the coral. Therefore, coral reefs are typically found in shallow, clear waters within the photic zone.<br \/>\n2.  **Clean and sediment free water:** Sediments suspended in water can block sunlight needed by zooxanthellae and can also smother coral polyps. Pollution can also harm corals. Clean water is essential.<br \/>\n3.  **Sea salinity of 6%:** This is incorrect. Coral reefs typically require stable salinity levels found in normal seawater, which is usually around 30-40 parts per thousand (ppt), or 3-4%. A salinity of 6% (60 ppt) is significantly higher than optimal and is not conducive to coral growth.<br \/>\n4.  **Tropical sea water with temperature of 20\u00b0C to 21\u00b0C:** Corals thrive in warm tropical and subtropical waters. The ideal temperature range for most reef-building corals is generally between 20\u00b0C and 28\u00b0C (68\u00b0F to 82\u00b0F). The range 20-21\u00b0C falls within this suitable range.<br \/>\n<\/section>\n<section id=\"pyq-additional-information\">\nOther conditions necessary for coral reef growth include adequate water circulation to bring nutrients and remove waste, and a hard substrate for larvae to settle on. Coral bleaching, a major threat to reefs, occurs when corals expel their symbiotic algae, often due to increased water temperature.<br \/>\n<\/section>\n","protected":false},"excerpt":{"rendered":"<p>Which of the following are the necessary conditions for the growth of coral reefs? 1. Photic conditions 2. Clean and sediment free water 3. Sea salinity of 6% 4. Tropical sea water with temperature of 20\u00b0C to 21\u00b0C Select the correct answer using the code given below : [amp_mcq option1=&#8221;1, 2 and 4 only&#8221; option2=&#8221;2 &#8230; <\/p>\n<p class=\"read-more-container\"><a title=\"Which of the following are the necessary conditions for the growth of\" class=\"read-more button\" href=\"https:\/\/exam.pscnotes.com\/mcq\/which-of-the-following-are-the-necessary-conditions-for-the-growth-of\/#more-90174\">Detailed Solution<span class=\"screen-reader-text\">Which of the following are the necessary conditions for the growth of<\/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":[1085],"tags":[1101,1367,1136],"class_list":["post-90174","post","type-post","status-publish","format-standard","hentry","category-upsc-capf","tag-1101","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>Which of the following are the necessary conditions for the growth of<\/title>\n<meta name=\"description\" content=\"The correct answer is A) 1, 2 and 4 only. Coral reefs are complex ecosystems built by tiny marine animals called coral polyps. Their growth depends on specific environmental conditions: 1. **Photic conditions:** Corals have a symbiotic relationship with photosynthetic algae called zooxanthellae living in their tissues. These algae require sunlight for photosynthesis, which provides energy to the coral. Therefore, coral reefs are typically found in shallow, clear waters within the photic zone. 2. **Clean and sediment free water:** Sediments suspended in water can block sunlight needed by zooxanthellae and can also smother coral polyps. Pollution can also harm corals. Clean water is essential. 3. **Sea salinity of 6%:** This is incorrect. Coral reefs typically require stable salinity levels found in normal seawater, which is usually around 30-40 parts per thousand (ppt), or 3-4%. A salinity of 6% (60 ppt) is significantly higher than optimal and is not conducive to coral growth. 4. **Tropical sea water with temperature of 20\u00b0C to 21\u00b0C:** Corals thrive in warm tropical and subtropical waters. The ideal temperature range for most reef-building corals is generally between 20\u00b0C and 28\u00b0C (68\u00b0F to 82\u00b0F). The range 20-21\u00b0C falls within this suitable range.\" \/>\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\/which-of-the-following-are-the-necessary-conditions-for-the-growth-of\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Which of the following are the necessary conditions for the growth of\" \/>\n<meta property=\"og:description\" content=\"The correct answer is A) 1, 2 and 4 only. Coral reefs are complex ecosystems built by tiny marine animals called coral polyps. Their growth depends on specific environmental conditions: 1. **Photic conditions:** Corals have a symbiotic relationship with photosynthetic algae called zooxanthellae living in their tissues. These algae require sunlight for photosynthesis, which provides energy to the coral. Therefore, coral reefs are typically found in shallow, clear waters within the photic zone. 2. **Clean and sediment free water:** Sediments suspended in water can block sunlight needed by zooxanthellae and can also smother coral polyps. Pollution can also harm corals. Clean water is essential. 3. **Sea salinity of 6%:** This is incorrect. Coral reefs typically require stable salinity levels found in normal seawater, which is usually around 30-40 parts per thousand (ppt), or 3-4%. A salinity of 6% (60 ppt) is significantly higher than optimal and is not conducive to coral growth. 4. **Tropical sea water with temperature of 20\u00b0C to 21\u00b0C:** Corals thrive in warm tropical and subtropical waters. The ideal temperature range for most reef-building corals is generally between 20\u00b0C and 28\u00b0C (68\u00b0F to 82\u00b0F). The range 20-21\u00b0C falls within this suitable range.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/exam.pscnotes.com\/mcq\/which-of-the-following-are-the-necessary-conditions-for-the-growth-of\/\" \/>\n<meta property=\"og:site_name\" content=\"MCQ and Quiz for Exams\" \/>\n<meta property=\"article:published_time\" content=\"2025-06-01T10:22:16+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":"Which of the following are the necessary conditions for the growth of","description":"The correct answer is A) 1, 2 and 4 only. Coral reefs are complex ecosystems built by tiny marine animals called coral polyps. Their growth depends on specific environmental conditions: 1. **Photic conditions:** Corals have a symbiotic relationship with photosynthetic algae called zooxanthellae living in their tissues. These algae require sunlight for photosynthesis, which provides energy to the coral. Therefore, coral reefs are typically found in shallow, clear waters within the photic zone. 2. **Clean and sediment free water:** Sediments suspended in water can block sunlight needed by zooxanthellae and can also smother coral polyps. Pollution can also harm corals. Clean water is essential. 3. **Sea salinity of 6%:** This is incorrect. Coral reefs typically require stable salinity levels found in normal seawater, which is usually around 30-40 parts per thousand (ppt), or 3-4%. A salinity of 6% (60 ppt) is significantly higher than optimal and is not conducive to coral growth. 4. **Tropical sea water with temperature of 20\u00b0C to 21\u00b0C:** Corals thrive in warm tropical and subtropical waters. The ideal temperature range for most reef-building corals is generally between 20\u00b0C and 28\u00b0C (68\u00b0F to 82\u00b0F). The range 20-21\u00b0C falls within this suitable range.","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\/which-of-the-following-are-the-necessary-conditions-for-the-growth-of\/","og_locale":"en_US","og_type":"article","og_title":"Which of the following are the necessary conditions for the growth of","og_description":"The correct answer is A) 1, 2 and 4 only. Coral reefs are complex ecosystems built by tiny marine animals called coral polyps. Their growth depends on specific environmental conditions: 1. **Photic conditions:** Corals have a symbiotic relationship with photosynthetic algae called zooxanthellae living in their tissues. These algae require sunlight for photosynthesis, which provides energy to the coral. Therefore, coral reefs are typically found in shallow, clear waters within the photic zone. 2. **Clean and sediment free water:** Sediments suspended in water can block sunlight needed by zooxanthellae and can also smother coral polyps. Pollution can also harm corals. Clean water is essential. 3. **Sea salinity of 6%:** This is incorrect. Coral reefs typically require stable salinity levels found in normal seawater, which is usually around 30-40 parts per thousand (ppt), or 3-4%. A salinity of 6% (60 ppt) is significantly higher than optimal and is not conducive to coral growth. 4. **Tropical sea water with temperature of 20\u00b0C to 21\u00b0C:** Corals thrive in warm tropical and subtropical waters. The ideal temperature range for most reef-building corals is generally between 20\u00b0C and 28\u00b0C (68\u00b0F to 82\u00b0F). The range 20-21\u00b0C falls within this suitable range.","og_url":"https:\/\/exam.pscnotes.com\/mcq\/which-of-the-following-are-the-necessary-conditions-for-the-growth-of\/","og_site_name":"MCQ and Quiz for Exams","article_published_time":"2025-06-01T10:22:16+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\/which-of-the-following-are-the-necessary-conditions-for-the-growth-of\/","url":"https:\/\/exam.pscnotes.com\/mcq\/which-of-the-following-are-the-necessary-conditions-for-the-growth-of\/","name":"Which of the following are the necessary conditions for the growth of","isPartOf":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#website"},"datePublished":"2025-06-01T10:22:16+00:00","dateModified":"2025-06-01T10:22:16+00:00","author":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/5807dafeb27d2ec82344d6cbd6c3d209"},"description":"The correct answer is A) 1, 2 and 4 only. Coral reefs are complex ecosystems built by tiny marine animals called coral polyps. Their growth depends on specific environmental conditions: 1. **Photic conditions:** Corals have a symbiotic relationship with photosynthetic algae called zooxanthellae living in their tissues. These algae require sunlight for photosynthesis, which provides energy to the coral. Therefore, coral reefs are typically found in shallow, clear waters within the photic zone. 2. **Clean and sediment free water:** Sediments suspended in water can block sunlight needed by zooxanthellae and can also smother coral polyps. Pollution can also harm corals. Clean water is essential. 3. **Sea salinity of 6%:** This is incorrect. Coral reefs typically require stable salinity levels found in normal seawater, which is usually around 30-40 parts per thousand (ppt), or 3-4%. A salinity of 6% (60 ppt) is significantly higher than optimal and is not conducive to coral growth. 4. **Tropical sea water with temperature of 20\u00b0C to 21\u00b0C:** Corals thrive in warm tropical and subtropical waters. The ideal temperature range for most reef-building corals is generally between 20\u00b0C and 28\u00b0C (68\u00b0F to 82\u00b0F). The range 20-21\u00b0C falls within this suitable range.","breadcrumb":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/which-of-the-following-are-the-necessary-conditions-for-the-growth-of\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/exam.pscnotes.com\/mcq\/which-of-the-following-are-the-necessary-conditions-for-the-growth-of\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/exam.pscnotes.com\/mcq\/which-of-the-following-are-the-necessary-conditions-for-the-growth-of\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/exam.pscnotes.com\/mcq\/"},{"@type":"ListItem","position":2,"name":"UPSC CAPF","item":"https:\/\/exam.pscnotes.com\/mcq\/category\/upsc-capf\/"},{"@type":"ListItem","position":3,"name":"Which of the following are the necessary conditions for the growth of"}]},{"@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\/90174","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=90174"}],"version-history":[{"count":0,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts\/90174\/revisions"}],"wp:attachment":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/media?parent=90174"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/categories?post=90174"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/tags?post=90174"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}