Previous year MCQs

Environment & Ecology UPPSC 2023 GS-I
Question

The aquatic plant commonly used as bio fertilizer in the water-logged rice field is -

Answer & Solution

Answer: (Detailed Solution Below)

Option C: Azolla

Detailed Solution:

The correct answer is “Azolla”.
Azolla is an aquatic plant commonly used as a biofertilizer in waterlogged rice fields. It forms a symbiotic relationship with nitrogen-fixing bacteria (Anabaena), which helps in enriching the soil with nitrogen, improving soil fertility for rice cultivation.
Azolla is used in sustainable farming practices to enhance crop yields without relying on chemical fertilizers.

Similar Questions:

What is true about ecosystem?
  1. A) Primary Consumers are least dependent Upon Producer
  2. B) Primary Consumers are out-number producers
  3. C) Producers are more than Primary Consumers
  4. D) Secondary Consumers are the largest and most powerful
'Ozone layer' absorbing ultra violet radiation exists in which of the atmospheric layer?
  1. A) Troposphere
  2. B) Mesosphere
  3. C) Stratosphere
  4. D) Thermosphere
What is 'Green House Effect'?
  1. A) Increase in global temperature
  2. B) Decrease in global temperature
  3. C) Increase in sea water temperature
  4. D) Increase in temperature of rivers and lakes
Consider the following statements and select the correct answer from the code given below:

Assertion (A): The natural environment is clean
Reason(R): Human activities cause environ-mental pollution.

Code:
  1. A) Both A and R are correct arid R is the correct explanation of A
  2. B) Both A and R are correct but R is not the correct explanation of A
  3. C) A is correct but R is wrong
  4. D) A is correct but R is correct
Which one of the following is not correctly matched ?
  1. A) Rajaji National Park: Elephant
  2. B) Periyar National Park: Hangul
  3. C) Manas National Park: Elephant
  4. D) Dudhwa National Park: Tiger
Hangul-deer is found in which part of India?
  1. A) Kerala
  2. B) Rajasthan
  3. C) Assam
  4. D) Jammu and Kashmir
Match List-I with List-II and choose the correct answer using the codes given below the lists:
List-I - List-II
(Biosphere Reserve) - (State)

A. Simlipal - 1. Kerala
B. Nokrek - 2. Odisha
C. Agasthyamalai - 3. Assam
D. Manas - 4. Meghalaya

Codes:
A B C D
  1. A) 1 2 4 3
  2. B) 3 1 4 2
  3. C) 2 4 3 1
  4. D) 2 4 1 3
Given below are two statements, one is labelled as Assertion (A) and other as Reason (R):

Assertion (A) — The President can recommend to the Parliament to change the boundary of any state after seeking views of the concerned Legislature of that state on the subject within specified period.

Reason (R) — It is not mandatory for the President to accept the proposal of the concerned State Legislature.

Select the correct answer using the code given
below-
  1. A) Both (A) and (R) are true and (R) is correct explanation of (A)
  2. B) Both (A) and (R) are true but (R) is not correct explanation of (A)
  3. C) (A) is true but (R) is false
  4. D) (A) is false but (R) is true
Consider the following events and arrange these in correct chronological order starting from the earliest to the last activity-

(I) Appointment of the Drafting Committee
(II) Indian Constitution was adopted and enacted
(ill) Date of commencement of Indian Constitution
(IV) Constitution Assembly first met

Select the correct answer from the code given below
Code:
  1. A) III, II, I, IV
  2. B) IV, I, III, II
  3. C) I, II, IV, Ill
  4. D) lV, I, II, Ill
Assertion (A) :The Green Belt represent a planning concept for controlling the physical expansion of large cities.
Reason (R): It is an integral component of a city.

Select the correct answer by using the codes given below:
Codes:
  1. A) Both A and R are true and R is the correct explanation of A
  2. B) Both A and R are true but R is not the correct explanation of A
  3. C) A is true but R is false
  4. D) A is false but R is true
Which one of the following is the correct definition of "Agenda 21" ?
  1. A) It is an action plan of U.N.O. for protecting human rights.
  2. B) It is a book of 21 chapters on nuclear disarmament.
  3. C) It is an action plan for the conservation of global environment in 21st century.
  4. D) It is an agenda for the election of the President in the next meeting of SAARC.
Biodegradable pollutant is:
  1. A) Mercury
  2. B) Sewage
  3. C) Plastic
  4. D) Asbestos