All Courses
Explore Courses UPSC Exam UPSC Test Series Free Notes EduRev Infinity Get the App Login Join for Free
Sign in Open App
UPSC Exam  >  UPSC Questions  >  Phytoplankton are generally found in upper la... Start Learning for Free
SaveJoin the Discussion on the App
Phytoplankton are generally found in upper layers of ocean water because of
  1. Abundant sunlight in the upper layer of ocean water
  2. Absence of nutrients in deep ocean water
Select the correct answer code:
  • a)
    1 only 
  • b)
    2 only 
  • c)
    Both 1 and 2 
  • d)
    Neither 1 nor 2
Correct answer is option 'A'. Can you explain this answer?
FREE This question is part of
Download PDF Attempt Test
Download PDF Attempt this Test
Most Upvoted Answer
Phytoplankton are generally found in upper layers of ocean water becau...
Phytoplankton are microscopic marine plants that play a crucial role in the marine ecosystem as they are the primary producers of organic matter through photosynthesis. They are found in the upper layers of ocean water due to the abundant sunlight available in this region. This is explained by the following factors:

1. Abundant sunlight in the upper layer of ocean water:
- Phytoplankton require sunlight for photosynthesis, which is the process by which they convert sunlight, carbon dioxide, and nutrients into organic matter.
- The upper layers of ocean water receive the most sunlight compared to the deeper layers. Sunlight is able to penetrate the upper layers of the water due to its transparency.
- Sunlight is essential for the growth and survival of phytoplankton, as it provides the energy needed for photosynthesis to occur. Therefore, phytoplankton tend to concentrate in the upper layers of the ocean where they can access the maximum amount of sunlight.

2. Absence of nutrients in deep ocean water:
- While sunlight is abundant in the upper layers, deep ocean water receives very little sunlight, making it unsuitable for photosynthesis by phytoplankton.
- However, deep ocean water does contain nutrients such as nitrates, phosphates, and trace elements that are essential for phytoplankton growth.
- These nutrients are often brought to the surface through a process called upwelling, where cold, nutrient-rich water from the deep ocean rises to replace warmer surface water.
- As a result, the upper layers of ocean water are enriched with nutrients, making them ideal for phytoplankton growth.
- Phytoplankton can take up these nutrients from the water and use them for their growth and reproduction.

In conclusion, phytoplankton are generally found in the upper layers of ocean water due to the combination of abundant sunlight and the presence of nutrients. The sunlight allows them to carry out photosynthesis, while the nutrients in the upper layers provide the necessary resources for their growth and survival. This distribution of phytoplankton in the ocean is essential for maintaining the balance of marine ecosystems and supporting other marine organisms.
Free Test
FREE
Start Free Test
Start Free Test
Community Answer
Phytoplankton are generally found in upper layers of ocean water becau...
  • Phytoplankton in the open ocean need both sunlight and nutrients (such as nitrate and phosphate) to be able to photosynthesize. 
  • Abundant Sunlight is available in the uppermost layers.
  • During photosynthesis, the nutrients are quickly used up by phytoplankton so they are not available for long periods in the upper layers under normal circumstances.
  • This is indeed the case in tropical waters, and as a result they are very unproductive.
  • To escape this problem the seawater needs to be mixed regularly to bring the nutrient rich deep waters up to the sunlight zone where the phytoplankton can grow.
< Previous Question Next Question >
Explore Courses for UPSC exam

Similar UPSC Doubts

Passage -1The law in many parts of the world increasingly restricts the discharge of agricultural slurry into watercourses. The simplest and often the most economically sound practice returns the material to the land as semisolid manure or as sprayed slurry. This dilutes its concentration in the environment to what might have occurred III a more primitive and sustainable type of agriculture and converts pollutant into fertilizer. Soil microorganisms decompose the organic components of sewage and slurry and most of the mineral nutrients become available to be absorbed again by the vegetation.The excess input of nutrients, both nitrogen and phosphorus - based, from agricultural runoff (and human sewag e) has caused many healthy oligotrophic lakes (low nutrient concentrations, low plant productivity with abundant water weeds, and clear water) to change to eutrophic condition where high nutrient inputs lead to high phytoplankton productivity (sometimes dominated by bloomforming toxic species). This makes the water turbid, eliminates large plants and, in the worst situations, leads to anoxia and fish kills; so called cultural eutrophication. Thus, important ecosystem services are lost, including the provisioning service of wild-caught fish and the cultural services associated with recreation.The process of cultural eutrophication of lakes has been understood for some time. But only recently did scientists notice huge dead zones in the oceans near river outlets, particularly those draining large catchment areas such as the Mississippi in North America and the Yangtze in China. The nutrient-enriched water flows through streams, rivers and lakes, and eventually to the estuary and ocean where the ecological impact may be huge, killing virtually all invertebrates and fish in areas up to 70,000 km2 in extent. More than 150 sea areas worldwide are now regularly starved of oxygen as a result of decomposition of algal blooms, fuelled particularly by nitrogen from agricultural runoff of fertilizers and sewage from large cities. Oceanic dead zones are typically associated withindustrialized nations and usually lie off- countries that subsidize their agriculture, encouraging farmers to increase productivity and use more fertilizer.Q.What is/are the characteristics of a water body with cultural eutrophication?1. Loss of ecosystem services2. Loss of flora and fauna3. Loss of mineral nutrients

Passage -1The law in many parts of the world increasingly restricts the discharge of agricultural slurry into watercourses. The simplest and often the most economically sound practice returns the material to the land as semisolid manure or as sprayed slurry. This dilutes its concentration in the environment to what might have occurred III a more primitive and sustainable type of agriculture and converts pollutant into fertilizer. Soil microorganisms decompose the organic components of sewage and slurry and most of the mineral nutrients become available to be absorbed again by the vegetation.The excess input of nutrients, both nitrogen and phosphorus - based, from agricultural runoff (and human sewag e) has caused many healthy oligotrophic lakes (low nutrient concentrations, low plant productivity with abundant water weeds, and clear water) to change to eutrophic condition where high nutrient inputs lead to high phytoplankton productivity (sometimes dominated by bloomforming toxic species). This makes the water turbid, eliminates large plants and, in the worst situations, leads to anoxia and fish kills; so called cultural eutrophication. Thus, important ecosystem services are lost, including the provisioning service of wild-caught fish and the cultural services associated with recreation.The process of cultural eutrophication of lakes has been understood for some time. But only recently did scientists notice huge dead zones in the oceans near river outlets, particularly those draining large catchment areas such as the Mississippi in North America and the Yangtze in China. The nutrient-enriched water flows through streams, rivers and lakes, and eventually to the estuary and ocean where the ecological impact may be huge, killing virtually all invertebrates and fish in areas up to 70,000 km2 in extent. More than 150 sea areas worldwide are now regularly starved of oxygen as a result of decomposition of algal blooms, fuelled particularly by nitrogen from agricultural runoff of fertilizers and sewage from large cities. Oceanic dead zones are typically associated withindustrialized nations and usually lie off- countries that subsidize their agriculture, encouraging farmers to increase productivity and use more fertilizer.Q.According to the passage, what are the effects of indiscriminate use of fertilizers?1. Addition of pollutants to the soil and water.2. Destruction decomposer of microorganisms in soil.3. Nutrient enrichment of water bodies.4. Creation of algal blooms.

Directions for the following 7 (seven) items: Read the following two passages and answer the items that follow each passage. Your answers to these items should be based on the passages only.Passage -1The law in many parts of the world increasingly restricts the discharge of agricultural slurry into watercourses. The simplest and often the most economically sound practice returns the material to the land as semisolid manure or as sprayed slurry. This dilutes its concentration in the environment to what might have occurred III a more primitive and sustainable type of agriculture and converts pollutant into fertilizer. Soil microorganisms decompose the organic components of sewage and slurry and most of the mineral nutrients become available to be absorbed again by the vegetation.The excess input of nutrients, both nitrogen and phosphorus - based, from agricultural runoff (and human sewag e) has caused many healthy oligotrophic lakes (low nutrient concentrations, low plant productivity with abundant water weeds, and clear water) to change to eutrophic condition where high nutrient inputs lead to high phytoplankton productivity (sometimes dominated by bloomforming toxic species). This makes the water turbid, eliminates large plants and, in the worst situations, leads to anoxia and fish kills; so called cultural eutrophication. Thus, important ecosystem services are lost, including the provisioning service of wild-caught fish and the cultural services associated with recreation.The process of cultural eutrophication of lakes has been understood for some time. But only recently did scientists notice huge dead zones in the oceans near river outlets, particularly those draining large catchment areas such as the Mississippi in North America and the Yangtze in China. The nutrient-enriched water flows through streams, rivers and lakes, and eventually to the estuary and ocean where the ecological impact may be huge, killing virtually all invertebrates and fish in areas up to 70,000 km2 in extent. More than 150 sea areas worldwide are now regularly starved of oxygen as a result of decomposition of algal blooms, fuelled particularly by nitrogen from agricultural runoff of fertilizers and sewage from large cities. Oceanic dead zones are typically associated withindustrialized nations and usually lie off- countries that subsidize their agriculture, encouraging farmers to increase productivity and use more fertilizer.Q.According to the passage, why should the discharge of agricultural slurry into watercourses be restricted?1. Losing nutrients in this way is not a good practice economically.2. Watercourses do not contain the microorganisms that can decompose organic components of agricultural slurry.3. The discharge may lead to the eutrophication of water bodies.

Passage -1The law in many parts of the world increasingly restricts the discharge of agricultural slurry into watercourses. The simplest and often the most economically sound practice returns the material to the land as semisolid manure or as sprayed slurry. This dilutes its concentration in the environment to what might have occurred III a more primitive and sustainable type of agriculture and converts pollutant into fertilizer. Soil microorganisms decompose the organic components of sewage and slurry and most of the mineral nutrients become available to be absorbed again by the vegetation.The excess input of nutrients, both nitrogen and phosphorus - based, from agricultural runoff (and human sewag e) has caused many healthy oligotrophic lakes (low nutrient concentrations, low plant productivity with abundant water weeds, and clear water) to change to eutrophic condition where high nutrient inputs lead to high phytoplankton productivity (sometimes dominated by bloomforming toxic species). This makes the water turbid, eliminates large plants and, in the worst situations, leads to anoxia and fish kills; so called cultural eutrophication. Thus, important ecosystem services are lost, including the provisioning service of wild-caught fish and the cultural services associated with recreation.The process of cultural eutrophication of lakes has been understood for some time. But only recently did scientists notice huge dead zones in the oceans near river outlets, particularly those draining large catchment areas such as the Mississippi in North America and the Yangtze in China. The nutrient-enriched water flows through streams, rivers and lakes, and eventually to the estuary and ocean where the ecological impact may be huge, killing virtually all invertebrates and fish in areas up to 70,000 km2 in extent. More than 150 sea areas worldwide are now regularly starved of oxygen as a result of decomposition of algal blooms, fuelled particularly by nitrogen from agricultural runoff of fertilizers and sewage from large cities. Oceanic dead zones are typically associated withindustrialized nations and usually lie off- countries that subsidize their agriculture, encouraging farmers to increase productivity and use more fertilizer.Q.The passage refers to the conversion of pollutant to fertilizer. What is pollutant and what is fertilizer in this context?

Top Courses for UPSCView all

Top Courses for UPSC

Phytoplankton are generally found in upper layers of ocean water because of Abundant sunlight in the upper layer of ocean water Absence of nutrients in deep ocean waterSelect the correct answer code:a)1 onlyb)2 onlyc)Both 1 and 2d)Neither 1 nor 2Correct answer is option 'A'. Can you explain this answer?
Question Description
Phytoplankton are generally found in upper layers of ocean water because of Abundant sunlight in the upper layer of ocean water Absence of nutrients in deep ocean waterSelect the correct answer code:a)1 onlyb)2 onlyc)Both 1 and 2d)Neither 1 nor 2Correct answer is option 'A'. Can you explain this answer? for UPSC 2024 is part of UPSC preparation. The Question and answers have been prepared according to the UPSC exam syllabus. Information about Phytoplankton are generally found in upper layers of ocean water because of Abundant sunlight in the upper layer of ocean water Absence of nutrients in deep ocean waterSelect the correct answer code:a)1 onlyb)2 onlyc)Both 1 and 2d)Neither 1 nor 2Correct answer is option 'A'. Can you explain this answer? covers all topics & solutions for UPSC 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Phytoplankton are generally found in upper layers of ocean water because of Abundant sunlight in the upper layer of ocean water Absence of nutrients in deep ocean waterSelect the correct answer code:a)1 onlyb)2 onlyc)Both 1 and 2d)Neither 1 nor 2Correct answer is option 'A'. Can you explain this answer?.
Solutions for Phytoplankton are generally found in upper layers of ocean water because of Abundant sunlight in the upper layer of ocean water Absence of nutrients in deep ocean waterSelect the correct answer code:a)1 onlyb)2 onlyc)Both 1 and 2d)Neither 1 nor 2Correct answer is option 'A'. Can you explain this answer? in English & in Hindi are available as part of our courses for UPSC. Download more important topics, notes, lectures and mock test series for UPSC Exam by signing up for free.
Here you can find the meaning of Phytoplankton are generally found in upper layers of ocean water because of Abundant sunlight in the upper layer of ocean water Absence of nutrients in deep ocean waterSelect the correct answer code:a)1 onlyb)2 onlyc)Both 1 and 2d)Neither 1 nor 2Correct answer is option 'A'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of Phytoplankton are generally found in upper layers of ocean water because of Abundant sunlight in the upper layer of ocean water Absence of nutrients in deep ocean waterSelect the correct answer code:a)1 onlyb)2 onlyc)Both 1 and 2d)Neither 1 nor 2Correct answer is option 'A'. Can you explain this answer?, a detailed solution for Phytoplankton are generally found in upper layers of ocean water because of Abundant sunlight in the upper layer of ocean water Absence of nutrients in deep ocean waterSelect the correct answer code:a)1 onlyb)2 onlyc)Both 1 and 2d)Neither 1 nor 2Correct answer is option 'A'. Can you explain this answer? has been provided alongside types of Phytoplankton are generally found in upper layers of ocean water because of Abundant sunlight in the upper layer of ocean water Absence of nutrients in deep ocean waterSelect the correct answer code:a)1 onlyb)2 onlyc)Both 1 and 2d)Neither 1 nor 2Correct answer is option 'A'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice Phytoplankton are generally found in upper layers of ocean water because of Abundant sunlight in the upper layer of ocean water Absence of nutrients in deep ocean waterSelect the correct answer code:a)1 onlyb)2 onlyc)Both 1 and 2d)Neither 1 nor 2Correct answer is option 'A'. Can you explain this answer? tests, examples and also practice UPSC tests.
Explore Courses for UPSC exam

Top Courses for UPSC

Explore Courses

Suggested Free Tests

Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev
Get App
© EduRev
Education Revolution
Follow Us
Signup to see your scores go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup