Tag: evs

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Questions Related to evs

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

Which of the following groups of herbicides is derived from urea, and is used for controlling weeds in tea, tobacco and cotton?

  1. Carbamates

  2. Triazines

  3. Pyrethroids

  4. Organophosphate
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A carbamate is an organic compound which is derived from carbamic acid (NH$ _{2}$COOH). 

A pyrethroid is an organic compound similar to the natural pyrethrins produced by the flowers of pyrethrums (Chrysanthemum cinerariaefolium and C. coccineum). Pyrethroids now constitute the majority of commercial household insecticides. 
An organophosphate or phosphate ester is the general name for esters of phosphoric acid. 
Triazines show antimalarial, antibacterial, and antimicrobial activities. They are derived from urea and used in tea, cotton and tobacco plantation and some orchid plantation. Thus, option B is correct.

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

Weeds affect the crop plants by

  1. Killing the crop plants before they grow

  2. Secreting poisons which cause diseases in crop plants

  3. Competing for various resources of crop plants causing low availability of nutrients

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Weeds are unwanted plants in the cultivated field. They compete with the crop plants for food, space and light. They take up the nutrients and reduce the growth of the  crop.

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

The most important weed against which eradication measures would be taken on war footings is

  1. Eichhornia

  2. Dactylis

  3. Parthenium

  4. Ageratum
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Parthenium is most common weed which grows anywhere on the land like roadsides, war footings etc.  It releases chemicals to supress the growth of plants and allergents toxic to other livestock. Thus it is important to supress  this weed first. Thus the correct answer is 'Parthenium'. 

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

The common weedicide used in cultivating fields is 

  1. 2, 4 - D

  2. 2,4,5 - T

  3. IAA

  4. ABA
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Weedicides can be defined as the pesticides used to kill the weeds. Bio-weedicides are called herbicides. Herbicide also commonly known as weedkillers, are pesticides used to kill unwanted plants. 2,4-D (2,4-dichlorophenoxy) is a systemic phenoxy herbicide developed in the 1940s and still in use today. The low cost of 2,4-D has led to continued usage, and it remains one of the most commonly used herbicides in the world. 
Multiple choice evs whose forests? improved methods of agriculture cropping patterns food for all conservation of forest and wildlife wildlife deforestation and conservation

An American plant, which had become a troublesome waterweed in India is

  1. Typha latifolia

  2. Trapa bispinosa

  3. Cyperus rotundus

  4. Eichhornia crassipes
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Eichhornia crassipes also known with the common name of water hyacinth is a free-floating aquatic plant native to America. It is often considered a highly problematic invasive species outside its native range. E. crassipes reproduces both vegetatively and sexually, but the vegetative reproduction is responsible for the plant’s rapid spread and colonization of water bodies. It occurs through the formation of stolons, which produce daughter plants. This is generally very rapid, if the temperature is high and nutrients are available, it often invades bodies of water that have been impacted by human activities as they often receive large amounts of nutrients. One plant can multiply to cover one acre in a single growing season forming a dense strand. So, with the combination of its free-floating habit, rapid vegetative propagation, and ability to survive on mud during periods of low water levels, E. crassipes has been able to naturalize in a wide variety of aquatic habitats.

Therefore, the correct answer is option D.

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

Weeds affect the crop plants by

  1. Killing of plants in field before they grow

  2. Dominating the plants to grow

  3. Competing for various resources of crops causing low availability of nutrients

  4. All of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Weeds are nothing but unwanted crops that grow along with the main crop. Thus, they compete with the main crop for sunlight, water, nutrients, and space and thus reduce the resources available to them. In this way, they hamper the growth of the main crop.

So, option C is the correct answer.

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

................. helps in weed control.

  1. Mono cropping

  2. Multi cropping

  3. Both A and B

  4. Crop rotation
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

  • Rotating crops with ones that kill weeds by choking them out, such as hemp and other crops, can be a very effective method of weed control. 
  • It is a way to avoid the use of herbicides and to gain the benefits of crop rotation. 

Therefore, the correct answer is option D.

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

Weeds compete in which of the following with crop plants.

  1. Sunlight

  2. Space

  3. Nutrients

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The unwanted plants which grow in field along with the crop plants are termed as weed. They are harmful for the crops as they compete for nutrients, space and sunlight with them.

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

Troublesome American water weed found in India is

  1. Eichhornia

  2. Trapa

  3. Cyperus

  4. Typha
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The  Eichhornia , commonly known as common water hyacinth, is an aquatic plant native to the Amazon basin, and is often a highly problematic invasive species outside its native range . It grows at an alarming rate and spreads on the surface of the water body. This cut out of the light and it also causes an increase in the oxygen demand. Thus, causing the death of fishes and other aquatic organisms. 

So the correct answer is 'Eichhornia'