Paragraph: Geographers analyzed 175 satellite images of ocean colour,
which is an indicator of Phytoplankton productivity at the ocean’s surface, and found that giant icebergs are responsible for storing up to 20 percent of carbon in the Southern Ocean. The researchers discovered that melting water from giant icebergs which contains iron and other nutrients, supports hitherto unexpectedly high levels of phytoplankton growth.
Q. Based on the above passage, the following assumptions have been made:
1. Giant icebergs have a bearing on primary productivity and food chains of the Southern Ocean.
2. Melting of giant icebergs can produce climate change effects and impact world fisheries.
Which of the assumptions given above is/are valid?
a) 1 only
b) 2 only
c) Both 1 and 2
d) Neither 1 nor 2
Correct answer: a) 1 only
Question from UPSC Prelims 2024 CSAT
Explanation :
1. Let’s examine Assumption 1:
– The passage states that giant icebergs contribute to phytoplankton growth through nutrients in melting water
– Phytoplankton are primary producers in ocean food chains
– Therefore, if icebergs affect phytoplankton growth, they directly affect primary productivity and food chains
– This assumption is clearly supported by the information given
2. Let’s examine Assumption 2:
– The passage only mentions that icebergs store carbon and affect phytoplankton growth
– No information is provided about:
– Climate change effects
– Impact on world fisheries
– This assumption goes beyond the scope of information provided
3. Evaluating the options:
a) 1 only – Only Assumption 1 is valid
b) 2 only – Incorrect as Assumption 2 is not supported
c) Both 1 and 2 – Incorrect as only 1 is valid
d) Neither 1 nor 2 – Incorrect as 1 is valid
The correct answer is a) 1 only, because:
– Only Assumption 1 can be directly validated from the information provided in the passage
– Assumption 2 makes claims about climate change and fisheries that aren’t supported by the given text