Tag: zoology

Questions Related to zoology

TCDD stands for

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

  1. Trichloro-nitro-dimethane

  2. Trichloro-dinitro-diethylamide

  3. Tetrachlorodibenzo-p-dioxin

  4. None of the above

Show answer
Correct Option: C
Explanation:

TCDD is 2,3,7,8-tetrachlorodibenzo-p-dioxin, is a polychlorinated dibenzo-p-dioxin.

TCDD is a colourless solid with no distinguishable odour at room temperature. It is usually formed as a side product in organic synthesis and burning of organic materials. TCDD is the most potent compound (congener) of it's series and became known as a contaminant in agent orange, a herbicide used in the Vietnam war.
Thus, the correct answer is option C.

Bordeaux mixture was discovered by

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

  1. Paul Muller

  2. M. N. Saha

  3. C. H. Barrat

  4. P M A Millardert

Show answer
Correct Option: D
Explanation:

Bordeaux mixture (also called Bordo Mix) is a mixture of copper(II) sulfate and slaked lime, used as a fungicide. It is used in vineyards, fruit-farms and gardens to prevent infestations of downy mildew, powdery mildew and other fungi. Bordeaux mixture was discovered by P M A Millardert.

Biological control component is central to advanced agricultural production. Which of the following is used as a third generation pesticide?

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

  1. Pathogens

  2. Pheromones

  3. Insect repellants

  4. Insect hormone analogues

Show answer
Correct Option: D
Explanation:

The first-generation pesticides, which were used prior to 1940, consisted of compounds such as arsenic, mercury, and lead. These were soon abandoned because they were highly toxic and ineffective. The second-generation pesticides were composed of synthetic organic compounds.

Insect hormone analogues are used as a third generation pesticide. These  are far superior to the lead arsenate and DDT that epitomize the two earlier generations. These chemicals, called as juvenile hormones, are made in two small glands in insect's heads. Juvenile hormone must be secreted at certain stages in an insect's life and not secreted at other times.
A pathogen is anything that causes a disease. 
A pheromone is a chemical an animal produces which changes the behavior of another animal of the same species (animals include insects). Some describe pheromones as behavior-altering agents. Many people do not know that pheromones trigger other behaviors in the animal of the same species, apart from sexual behavior.
Insect repellant  is a substance applied to skin, clothing, or other surfaces which discourages insects (and arthropods in general) from landing or climbing on that surface.
Therefore, the correct answer is option D.

Most famous pesticide of the world is 

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

  1. Methyl isocyanate

  2. DDT

  3. Malathion

  4. None of the above

Show answer
Correct Option: B
Explanation:

DDT is one of the most famous pesticides in the world, and it has been with us for quite a long time. As a pesticide, DDT was first used during world war II. It was so effective as an insect killer that some called it as the "atomic bomb" of pesticides.

Thus, the correct answer is option B. 

The pesticide most toxic to vertebrates are

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

  1. Organo phosphate

  2. Organochlorine

  3. Carbamates

  4. Parathion

Show answer
Correct Option: A
Explanation:

Organophosphate (OP) compounds are the most widely used group of insecticides in the world. Their acute toxicity causes a hazard both to professional and amateur users. OPs were first recognised in 1854, but their general toxicity was not established until the 1930s. Tetraethyl pyrophosphate (TEPP) was the first OP insecticide, which was developed in Germany during World War Two as a by-product of nerve gas development. OPs are all derived from phosphoric acid. They are generally among the most acutely toxic of all pesticides to vertebrate animals. They are also unstable and therefore break down relatively quickly in the environment. So, organo phosphates are more toxic to vertebrates compared to organo chlorine, carbamates and parathion. Thus, option A is correct and other options are wrong.

2, 4-D is a 

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

  1. Insecticide

  2. Weedicide

  3. Fungicide

  4. Rodenticide

Show answer
Correct Option: B
Explanation:

2, 4-D is a weedicide. 2,4-Dichlorophenoxyacetic acid  is a common systemic herbicide used in the control of broadleaf weeds. It is a synthetic auxin (plant hormone) and one of the most widely used herbicides in the world. 2,4-D is a possible carcinogen per WHO.

2,4-D was one of the ingredients in Agent Orange, a herbicide widely used during the Vietnam War. 2,4-D is primarily used as a selective herbicide which kills many terrestrial and aquatic broadleaf weeds, but not grasses. It acts by mimicking the action of the plant growth hormone auxin, which results in uncontrolled growth and eventually death in susceptible plants.
Weed is a wild plant growing where it is not wanted and in competition with cultivated plants. Weedicide is the chemical which kills weeds.
Therefore, the correct answer is option B.

Which of the following statements is incorrect?

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

  1. Biofertilizers are used to maintain and improve soil fertility.

  2. Chemical fertilizers pollute soil and water resources.

  3. Chemical fertilizers are expensive.

  4. Most pesticide used these days are specific in nature.

Show answer
Correct Option: D
Explanation:

Pesticides are chemicals used to eliminate or control a variety of agricultural pests that can damage crops and livestock and reduce farm productivity. The most commonly applied pesticides are insecticides (to kill insects), herbicides (to kill weeds), rodenticides (to kill rodents) and fungicides (to control fungi, mold, and mildew). Most pesticide used these days are not specific in nature. One pesticide can act on more than one type of pest. 

A biofertilizer (also bio-fertilizer) is a substance, which contains living microorganisms which, when applied to seed, plant surfaces or soil, colonizes the rhizosphere or the interior of the plant and promotes growth by increasing the supply or availability of primary nutrients to the host plant. Biofertilizers are used to maintain and improve soil fertility. 
Chemical fertilizers pollute soil and water resources and also they are expensive. 
Thus, the correct answer is option D.

Which one of the following is a third generation pesticides?

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

  1. Chemosterilants

  2. Organochlorines

  3. Antifeedants

  4. Carbamates

Show answer
Correct Option: C
Explanation:

Antifeedants are third generation pesticides. With the essential principles of hormonal insecticides worked out, the third generation insecticide may be just a few years away.

First-generation pesticides were primarily used prior to 1940 and consisted of inorganic and organic compounds. 
Minerals such as arsenic, mercury, and lead are inorganic compounds and were used as early pesticides. These minerals, when used as pesticides, posed a problem, because they did not degrade in the environment. The minerals persist and accumulate in the soil until the levels become so high, that the land is unfertile.
Organic compounds were created from plants, and pesticides used the plants developed resistance to insects. These organic compounds are known as botanicals. Pesticides such as pyrethrin come from chrysanthemum flowers. Rotenone is isolated from jewel vine and nicotine is found in tobacco. Unlike Inorganic compounds, botanicals do degrade in the environment and do not persist. However, these pesticides are highly toxic to other organisms such as fish and bees. 
Synthetic botanicals were also produced as first-generation pesticides. They are created chemically to mimic the structure of plant produced botanicals. Pyrethroid, similar to the botanical version of pyrethrin, was an important synthetic botanical because it did not persist in the environment.
Second-Generation Pesticides- Second-generation pesticides differ from earlier pesticides, in which they are created synthetically. They began to be used in the 1940s after Paul Müller discovered DDT in 1939. The three most common groups of second-generation pesticides are Chlorinated hydrocarbons, Organophosphates, and Carbamates. These groups are known as insecticides. Each group displays different properties. Some insecticides are persistent while others break down and do not bioaccumulate. Their toxicity to mammals also fluctuates between insecticides.
Examples of Second Generation Pesticides-
Chlorinated hydrocarbons
            -DDT
            -Methoxychlor
            -Lindane
            -Endosulfan
Organophosphates
            -Methamidophos
            -Dimethoate
            -Malathion
Carbamates
    -Aldicarb
    -Carbaryl

DDT is a/an

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

  1. Carbamate

  2. Organophosphate

  3. Organochlorine

  4. Triazine

Show answer
Correct Option: C
Explanation:

DDT (dichlorodiphenyltrichloroethane) is a colourless, crystalline, tasteless and almost odourless organochloride. It is known for its insecticidal properties. DDT has been formulated in almost every conceivable form, including solutions in xylene or petroleum distillates, emulsifiable concentrates, water-wettable powders, granules, aerosols, smoke candles and charges for vaporizers and lotions. Thus, the correct answer is option C.

Which one of the following statements is correct?

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

  1. At present, it is not possible to grow maize without chemical fertilizers.

  2. Extensive use of chemical fertilizers may lead to eutrophication of nearby water bodies.

  3. Both, Azotobacter and Rhizobium fix atmospheric nitrogen in root nodules of plants.

  4. Cyanobacteria such as Anabaena and Nostoc are important mobilizers of phosphates and potassium for plant nutrition in soil.

Show answer
Correct Option: B
Explanation:
Eutrophication occurs when a lake gets too many nutrients, causing blue-green algae growth. Eventually, the growth peaks and crashes as oxygen is consumed faster than it can be replenished, a condition called as eutrophication. Extensive use of chemical fertilizers leads to eutrophication of nearby water bodies. 
Thus, the correct answer is option B.