Tag: evs

Questions Related to evs

Congress grass is

evs whose forests? improved methods of agriculture cropping patterns food for all conservation of forest and wildlife wildlife deforestation and conservation

  1. Cynodon dactylon

  2. Digitaria purpurea

  3. Cymbopogon citratus

  4. Parthenium hysterophorus

Show answer
Correct Option: D
Explanation:

Congress grass is the common name for Parthenium hysterophorus . It is a species of flowering plant in the aster family, Asteraceae. 

So the correct answer is 'Parthenium hysterophorus'

Which one is a troublesome weed of agricultural fields?

evs whose forests? improved methods of agriculture cropping patterns food for all conservation of forest and wildlife wildlife deforestation and conservation

  1. Chenopodium album

  2. Cyperus rotundus

  3. Parthenium hysterophorus

  4. Eichhornia crassipes

Show answer
Correct Option: C
Explanation:

Parthenium hysterophorus is commonly called as congress grass or gajar ghass .It is a species of flowering plant in the aster family, Asteraceae. It is native to the American tropics. This weed is equally dangerous for all flora and fauna. It is highly dangerous for humans. It utilizes most of  the nutritious substances from soils, thus converting fertile ground into unfertile ones.

So the correct answer is 'Parthenium hysterophorus'

Agent Orange consisted of

evs whose forests? improved methods of agriculture cropping patterns food for all conservation of forest and wildlife wildlife deforestation and conservation

  1. 2,4 - D

  2. 2,4,5-T

  3. Dioxin as contaminant

  4. All the above

Show answer
Correct Option: D
Explanation:
  • Agent Orange refers to a herbicide mixture which was used by the U.S. military during the Vietnam War and it contained a dangerous chemical contaminant called dioxin. 
  • The active ingredient of Agent Orange was an equal mixture of two phenoxy herbicides – 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5 trichlorophenoxyacetic acid (2,4,5-T) and it also contained traces of the dioxin 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).
  • So the correct option is ' All of the above'.

What is manure?

evs a seeds tells a farmer's story manure manures and fertilisers water absorption organ

  1. It is a natural material obtained by decaying plant and animal waste.

  2. It is a synthetic material prepared in laboratory.

  3. It is a semi synthetic  material.

  4. It can be both natural and synthetic.

Show answer
Correct Option: A
Explanation:

Manure is a natural material, obtained by decaying plant and animal waste, that can be applied to the soil to enhance its fertility. Manure usually consist of faeces and urine of domestic livestock, with or without accompanying litter such as straw, hay, or bedding. The most common sources of manure are cows, horses, sheep.

So, the correct answer is 'It is a natural material obtained by decaying plant and animal waste '.

The organic manure is considered better than fertilisers because

evs a seeds tells a farmer's story manure manures and fertilisers water absorption organ

  1. It can be prepared in the factories.

  2. It is less rich in plant nutrient.

  3. It improves the texture of the soil.

  4. It decreases the water holding capacity of the soil.

Show answer
Correct Option: C
Explanation:

The organic manure contains a high amount of organic matter which increases the capability of the soil to hold the water. They are prepared by the decomposition of the organic matter by the microbes. They are highly rich in the plant nutrients. They also help to improve the quality and texture of the soil. The gaseous exchange takes place easily in this soil which allows the germination and growth of the plants properly. 

Thus, the correct answer is option C. 

The nodules present in the leguminous plants appear pink in colour due to the presence of 

evs a seeds tells a farmer's story manure manures and fertilisers water absorption organ

  1. RBC.s

  2. leghaemoglobin

  3. nitrogenase enzyme

  4. bacterial secretion

Show answer
Correct Option: B

Which of the following statements is incorrect about leghaemoglobin?

evs a seeds tells a farmer's story manure manures and fertilisers water absorption organ

  1. It acts as $O _2$ scavenger

  2. It imparts pink or red colour to the nodules

  3. It combines with $O _2$ and protects nitrogenase

  4. It is a Mo-Fe protein.

Show answer
Correct Option: D

Read the following statements and select the correct answer: - 


(i) Rhizobium leguminosarum is also known as Bacillus radicicola.
(ii) Nitrifying bacteria (Nitrosomonas, etc) are chemoautotrophs.
(iii) Enzyme nitrogenase fixes $N _2$ under aerobic conditions.
(iv) Leghaemoglobin creates aerobic conditions for the enzyme nitrogenase. 

evs a seeds tells a farmer's story manure manures and fertilisers water absorption organ

  1. Statements (i), (ii) and (iii) are correct

  2. Statements (i) and (ii) are correct

  3. Statements (iii) and (iv) are correct

  4. All statements are correct

Show answer
Correct Option: B
Explanation:

Statements I and ii are correct. Rhizobium leguminosarum is also known as Bacillus radicicola. Nitrifying bacteria (Nitrosomonas, etc) are chemoautotrophs. They use inorganic energy sources. However, the enzyme nitrogenase is highly sensitive to oxygen and gets readily oxidised in it's presence and Leghaemoglobin creates anerobic conditions for the enzyme nitrogenase by scavenging the oxygen molecules.

Thus, the correct answer is 'Statements (i) and (ii) are correct.' 

_______ conditions are created by leghaemoglobin in the root nodule of a legume.

evs a seeds tells a farmer's story manure manures and fertilisers water absorption organ

  1. Aerobic

  2. Anaerobic

  3. Acidic

  4. Alkaline

Show answer
Correct Option: B

Biofertilizers are organisms that enrich the nutrient quality of the soil. Which of the following can be used as biofertilisers ?

evs a seeds tells a farmer's story manure manures and fertilisers water absorption organ

  1. Nitrogen fixing cyanobacteria

  2. Nitrogen fixing bacteria

  3. Mycorrhizae

  4. All of these

Show answer
Correct Option: D
Explanation:
Nitrogen fixing cyanobacteria, Nitrogen fixing bacteria and mycorrhizae all can be used as biofertilisers as they all enrich the nutrient quality of the soil.
So, the correct option is 'All of these'