Tag: soil pollution-causes

Questions Related to soil pollution-causes

Atrazine is a

zoology soil pollution industrial chemicals and their harmful effects toxic wastes and their effects soil pollution-causes

  1. Chemical pesticide

  2. Herbicide

  3. Fertlizer

  4. None of the above

Show answer
Correct Option: B
Explanation:

Atrazine, a triazine herbicide, is used in corn and sorghum for control of broadleaf weeds and grasses. Still used because of its low cost and because it works well on a broad spectrum of weeds common in the US corn belt, atrazine is commonly used with other herbicides to reduce the overall rate of atrazine and to lower the potential for groundwater contamination; it is a photosystem II inhibitor.

Insecticides usually act upon

zoology soil pollution industrial chemicals and their harmful effects toxic wastes and their effects soil pollution-causes

  1. Muscular system

  2. Digestive system

  3. Nervous system

  4. Circulatory system

Show answer
Correct Option: C
Explanation:

Insecticides based on their target sites and mode of action at the target sites can be classified into neurotoxins and others which do not target the nervous system of the insects. Insects have highly specialised interconnected cells nervous system along which electrical charge (impulse) travel. Neurotoxins target the enzymes involved in neurotransmission. The prolonged and irreversible disruption of a normal functioning nervous system may result in death.

So, the correct answer is 'Nervous system'

Which one of the following is correct?

zoology soil pollution industrial chemicals and their harmful effects toxic wastes and their effects soil pollution-causes

  1. Herbicides kill plants by blocking PS II

  2. Insecticides kill insects through impairment of nerve conduction and sometimes respiratory arrest

  3. Both A and B

  4. None of the above

Show answer
Correct Option: C
Explanation:

Herbicides of photosystem-II inhibit the reduction of plastoquinone at the secondary quinone acceptor site and its subsequent re-oxidation. This consequently light induces charge separation which leads to recombination processes. This process generates reactive oxygen species causing extensive damage in PS II and eventually kills the plant.

 Insecticides, on the other hand,  prevent tiny electric pulses to move to from one neuron to another forming synapse or they open sodium ion channels in neuron causing them to fire spontaneously where insect go into spasm and die.
Hence, the correct answer is 'Both A and B'.

Now-a-days use of DDT as insecticide is banned because

zoology soil pollution industrial chemicals and their harmful effects toxic wastes and their effects soil pollution-causes

  1. It is less effective than other pesticides

  2. Organisms develop resistance to it

  3. Production cost is very high

  4. It has long residual effect

Show answer
Correct Option: D
Explanation:

Dichlorodiphenyltrichloroethane, commonly known as DDT, is a colourless, tasteless, and an almost odourless crystalline chemical compound, an organochlorine, originally developed as an insecticide, and ultimately becoming infamous for its environmental impacts. Opposition to DDT was focused by the 1962 publication of Rachel Carson's book Silent Spring. It catalogued environmental impacts that coincided with the widespread use of DDT in agriculture in the United States, and it questioned the logic of broadcasting potentially dangerous chemicals into the environment leaving the residues for a long time.

So the correct answer is 'It has a long residual effect'.

When EDTA solution added to ${ Mg }^{ 2+ }$ ion solution, then which of the following statement is not true?

zoology soil pollution industrial chemicals and their harmful effects toxic wastes and their effects soil pollution-causes

  1. Four coordinates sites of ${ Mg }^{ 2+ }$ are occupied by EDTA and remaining two sites are occupied by water molecules.

  2. All six coordinate sites of ${ Mg }^{ 2+ }$ are occupied

  3. pH of the solution is decreased

  4. Colorless $[{ Mg-EDTA }]^{ 2- }$ chelate is formed

Show answer
Correct Option: A
Explanation:
When EDTA solution added to the Mg2+ion solution, all six coordinate sites of Mg2+ are occupied, and a colourless [Mg−EDTA]2− chelate is formed. This reaction also results in the lowering of the pH of the solution.
So, the correct answer is 'Four coordinates sites of Mg2+ are occupied by EDTA and remaining two sites are occupied by water molecules.'

Which of the following weedicide can defoliate the complete forest?

zoology soil pollution industrial chemicals and their harmful effects toxic wastes and their effects soil pollution-causes

  1. 2, 4-D

  2. ABA 

  3. AMO 1618

  4. None of the above

Show answer
Correct Option: C
Explanation:

Weedicides or herbicides are weed killers or pesticides used to control weeds in agricultural farms. AMO 1618  or (2-isopropyl-5-methyl-4-trimethylammonium chloride)-phenyl-1-piperidine carboxylate is an  inhibitor of gibberellin biosynthesis which leads to retarded germination. Higher concentrations will lead to  reduced sensitivity of seeds.