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Environment & EcologyMediumAsked in: CDS · CDS-II 2017, GK

Which of the following radioactive substances enters/enter the human body through food chain and causes/cause many physiological disorders?

  1. A.Strontium-90
  2. B.Iodine-131
  3. C.Cesium-137
  4. D.All of the above

Correct answer

D. All of the above

Explanation

The correct answer is D, All of the above. Strontium-90, iodine-131 and caesium-137 are all fission products that settle on soil, water and plants and reach people through food.

These isotopes are released by nuclear weapon tests and reactor accidents such as Chernobyl (1986) and Fukushima (2011). Strontium-90 behaves like calcium, passes through grass and milk and is stored in bones, where it can cause bone cancer and leukaemia; its half-life is about 29 years. Iodine-131, with a half-life of only about 8 days, collects in the thyroid gland through milk and vegetables and can cause thyroid cancer, which is why potassium iodide tablets are given after an accident. Caesium-137 behaves like potassium, spreads through muscle tissue and lasts about 30 years.

Option A is incomplete, because strontium-90 is only one of the three. Option B is incomplete, because iodine-131 is also not the only one. Option C is incomplete, because caesium-137 is the third of the same group, so choosing it alone leaves the other two out.

Exam tip: Sr-90 to bones, I-131 to thyroid, Cs-137 to muscles.

Practice Questions

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Q2.Environment & EcologyAsked in: CDS · CDS-I 2019, GKMedium

Which one of the following statements about the National Green Tribunal is not correct?

  1. A.It was set up in the year 2010.
  2. B.It is involved in effective and expeditious disposal of cases relating to environmental protection and conservation of forests.
  3. C.It may consider giving relief and compensation for damages to persons and property.
  4. D.It is bound by the procedures laid down under the Code of Civil Procedure, 1908.
Show answer
Correct answer: D. It is bound by the procedures laid down under the Code of Civil Procedure, 1908.

The National Green Tribunal is not bound by the Code of Civil Procedure; it is guided by the principles of natural justice.

Q3.Environment & EcologyAsked in: CDS · CDS-I 2018, GKHard

Consider the following statements about National Wildlife Action Plan (NWAP) of India for 2017-2031:

1. This is the Third National Wildlife Action Plan.

2. The NWAP is unique as this is the first time India has recognized the concerns relating to climate change impact on wildlife.

3. The NWAP has ten components.

Which of the statements given above is/are correct?

  1. A.1 only
  2. B.1 and 2 only
  3. C.2 and 3 only
  4. D.1, 2 and 3
Show answer
Correct answer: B. 1 and 2 only

The plan for 2017-2031 is India's third National Wildlife Action Plan and the first to deal with the impact of climate change on wildlife, but it has five components, not ten.