Sarita Aggarwal solutions for बायोलॉजी [अंग्रेजी] कक्षा १२ आईएससी chapter 20 - Environmental Issues [Latest edition]

Which of the following is a non biodegradable pollutant?

Ozone depletion has resulted in ______.

Increase in CO₂ is harmful in atmosphere because it ______.

Acid rain is due to the precipitation of ______.

CFCs cause ______.

The greenhouse gases ______.

Photochemical smog is mainly composed of ______.

pH of acid rain is ______.

Eutrophication leads to death of fish due to ______.

Methaemoglobinemia is due to the following pollutant in drinking water.

The noise level that may lead to pain and physical discomfort is ______.

Minamata disease is caused by ______.

If DDT is sprayed in a lake, after 15 years, its highest concentration will be found in ______.

If BOD of a lake is high it means ______.

Which one of the following is a 'radiatively active gas'?

Ozone layer is present in ______.

Harmful UV rays of sun are absorbed by ______.

Ozone hole was first discovered over ______.

Nitrogen oxides produced from the emission of automobiles and power plants, are the source of fine airborne particles which lead to ______.

A lake with an inflow of domestic sewage rich in organic waste may result in ______.

Minamata disease was caused due to the consumption of ______.

Expand BOD.

The term 'Biomagnification' refers to the ______.

Formation of nonfunctional methaemoglobin causes blue baby syndrome. This is due to ______.

Which of the following is secondary pollutant?

Montreal protocol was passed in ______.

Photochemical smog pollution does not contain ______.

The montreal protocol refers to ______.

Greenhouse effect is due to ______.

Ozone hole results in

Ozone layer occurs in ______.

A lake near a village suffered heavy mortality of fishes within a few days. Consider the following reasons for this

1. lots of urea and phosphate fertilisers were used in the crops in the vicinity 
2. the area was sprayed with DDT by an aircraft 
3. the lake water turned green and stinky 
4. phytoplankton populations in the lake declined initially thereby greatly reducing photosynthesis Which two of the above were main reasons of fish mortality in the lake?

Increase in BOD in water leads to ______.

The agents that cause pollution are called ______.

______ pollutants can be broken down by microorganisms.

Global warming is a consequence of ______ effect caused by ______ level of carbon dioxide.

CFCs are used in and ______.

Depletion of ozone layer is caused by mainly ______.

______ and ______ are known as greenhouse gases.

Skeletal fluorosis causes symptoms of ______ and ______, and it is due to ______.

Excessive loading of nutrients in a lake leads to ______ causing ______ in O₂.

______, ______, ______ are the greenhouse gases that lead to warming up of earth's surface.

______ appears due to thinning of ozone layer every year over Antarctica during the month of August-September.

State whether the following is true or false.

Photochemical smog occurs due to warming up of air in winters.

State whether the following is true or false.

Acid rain causes erosion of brick and marble structures.

State whether the following is true or false.

High DO of water signifies water is clean.

State whether the following is true or false.

Industrial effluents containing high amount of nitrates released in water bodies cause eutrophication.

State whether the following is true or false.

Oxygen and nitrogen are greenhouse gases.

State whether the following is true or false.

Ozone layer is present in the stratosphere of earth.

State whether the following is true or false.

Ozone is one of the greenhouse gases responsible for creating ozone hole in Antarcticа.

State whether the following is true or false.

Minamata disease is caused by consuming water-containing cadmium.

State whether the following is true or false.

Global warming is as a result of enhanced greenhouse effect.

State whether the following is true or false.

Biological magnification is due to accumulation of non-biodegradable pollutants in the tissues of animals and their increased concentration in a food chain.

Match the following.

Answer the following in one or two words.

Poisonous compound formed by CO₂ with haemoglobin.

Answer the following in one or two words.

Gases that lead to global warming.

Answer the following in one or two words.

A disease caused due to mercury contaminated water.

Answer the following in one or two words.

Algal bloom seen in lakes due to excess loading of nutrients.

Answer the following in one or two words.

An annelid that is recognised as an indicator for polluted waters.

Assertion (A): Compressed natural gas (CNG) is a natural gas under pressure and is mainly composed of methane.

Reason (R): One of the advantages of using CNG as a fuel in automobiles is that it requires very less space for storage as compared to petrol or diesel. 

Assertion (A): Photochemical smog is mainly composed of nitrogen oxides, volatile organic compounds, ozone and peroxyacetyl nitrates.

Reason (R): Photochemical smog develops in cold weather conditions by the interaction of secondary pollutants.

Assertion (A): Excess of nitrates in drinking water are harmful for infants.

Reason (R): Nitrates are responsible for the 'blue-baby syndrome'.

Assertion (A): Eutrophication shows sudden increase in the growth of green plants or productivity in water.

Reason (R): With increasing eutrophication, there is depletion of dissolved oxygen in water which leads to death of most fish and aquatic life.

Assertion (A): Biological magnification is a phenomenon through which certain pollutants go on accumulating in increased concentration along the food chain.

Reason (R): The pollutants go on accumulating because they are non-biodegradable and each predator feeds on many preys and hence accumulates more.

Assertion (A): Handicapped children were born to mothers exposed to the atomic bombs during World War II even after many years.

Reason (R): Exposure of human body to radiations causes mutations.

Assertion (A): Deforestation is one main factor contributing to global warming.

Reason (R): Besides CO₂, two other gases – methane and CFCs are also included under greenhouse gases.

Assertion (A): UV radiation causes photo-dissociation of ozone into O₂ and O, thus causing damage to the stratospheric ozone layer.

Reason (R): Ozone hole is resulting in global warming and climate change.

Assertion (A): Chlorofluorocarbons (CFCs) are responsible for ozone depletion.

Reason (R): Ozone level or thickness is decreasing every year.

Assertion (A): Greenhouse gases inhibit the escape of total radiation by absorbing the long wave infrared radiations and reflecting them back towards the earth.

Reason (R): Greenhouse gases increase the temperature of earth.

Read the sources given and answer any four from the questions given below:

1. Smog gets formed when the
   1. air near the ground is warmer than high up air
   2. air near the ground is cooler than high up air
   3. high winds occur on warm days
   4. clouds cover the sky
2. Photochemical smog gets formed as a result of action of
   1. carbon dioxide and smoke
   2. carbon monoxide and smoke
   3. UV rays of sunlight and exhaust gases
   4. dust and sunlight
3. Smog contains secondary pollutants like
   1. carbon monoxide
   2. PAN
   3. ozone
   4. both (b) and (c)
4. The effect of smog on plants is
   1. damage to chlorophyll of leaves
   2. transpiration becomes more
   3. respiration becomes slow
   4. roots get damaged
5. The smoke from factories, normally goes up in the atmosphere because
   1. it rises up with the warm air coming from surface of earth.
   2. it rises up with the cool air coming from surface of earth.
   3. it moves towards the warm layer of upper atmosphere.
   4. it contains ozone that rises up.

Read the sources given and answer any four from the questions given below:

1. The sequence of wastewater treatment at Arcata project was
   1. sedimentation-chlorinationfiltration-marshlands
   2. sedimentation-filtrationmarshlands-chlorination
   3. sedimentation-filtration chlorination-marshlands
   4. marshlands-sedimentation-chlorination-filtration-marshlands
2. In Arcata project, the heavy metal pollutants are removed from wastewater by
   1. anaerobic bacteria of treatment plant
   2. algae, fungi and bacteria of marshlands
   3. aerobic bacteria of treatment plant
   4. chlorine-treated marshlands
3. The wastewater treatment project at Arcata is called an integrated project because
   1. it includes conventional treatment along with the use of fish in marshlands.
   2. it includes conventional treatment along with use of algae and fungi in marshlands.
   3. water gets purified naturally in marshlands only.
   4. it is a sanctuary.
4. What is the function of FOAM?
   1. to look after birds in the sanctuary
   2. to check working of wastewater treatment plant
   3. to safeguard biodiversity of the area
   4. to check flow of water in the area
5. When water passes through the marshlands, following pollutants get removed
   1. excess of carbon dioxide
   2. heavy suspended waste
   3. chlorine
   4. dissolved heavy metals

From various pollutants like sewage, paper, wood, aluminium, DDT, polythre bags, which ones are fiiode graduble.

Name two primary pollutants.

Name two secondary pollutants.

Expand - PAN

What are components present in smog?

Which system does PAN affect in the leaves?

What is the composition of acid rain?

If corrosion is seen on the marble monument and buildings, what can it be attributed to?

Name two devices to remove particulate air pollutants.

What does electrostatic precipitator remove?

What is the critical level of noise pollution for ear damage?

Name the pollutants present in domestic sewage?

If there is sudden increase of nutrients in the lakes and ponds and an algal bloom is seen, what is it called?

What harmful effect can eutrophication have in the river?

If Tubifex annelid is seen in a water body, does it signify anything?

If DDT sprayed in water is only 0.03 parts per billion but is found to be 100 times move in small or large fish, what is the reason for it? 

Name a disease that can be due to mercury poisoning.

What is another name for blue body syndrome?

What form can excess of fluoride do?

Name some sources of radioactive pollution.

Name the greenhouse gases.

What are the common main sources of CFCs?

Which gas has a relative higher contribution for greenhouse gases, and how much % age?

What is the effect on earth's temperature due to increase in greenhouse gases?

Extreme cold and hot temperature and rise in sea level is due to which phenomenon?

What are the ways to reduce global warming?

Where is ozone layer found in the atmosphere?

How is ozone formed?

How many km above sea level is ozone layer formed?

What is the thickness of ozone layer?

What is the function of ozone layer?

What is ozone hole?

What is the effect of ozone hole?

What is the effect of UV radiation on humans? State any 4 effects.

Name three important International initiatives regarding Global change.

What is deforestation?

List three main causes of deforestation.

List two ways of protecting forests.

Define the following term:

Pollution

Define the term pollutants.

Name a few biodegradable pollutants.

Name a few non-biodegradable pollutants.

Name few man-made sources of air pollution.

What is photochemical smog composed of?

Give the reactions involved in the formation of smog?

What is the composition of acid rain?

Give the principle of electric precipitator.

Name two devices used to remove particulate pollutants.

Define the term 'Biological oxygen demand' (BOD).

What is COD?

Name the disease caused by excess nitrate.

Name the disease caused by arsenic.

Name the disease caused by mercury in water.

What is methaemoglobin?

State the causes of ‘eutrophication’.

Define biological magnification.

Why is DO content low after thermal pollution?

Name an animal species that acts as an indicator of water pollution.

Name two point sources of water pollution.

Name two non-point sources of water pollution.

Name the following: 

Any three water-borne disease

Define the term:

Soil pollution

What is the unit of measurement of noise or sound level?

At which noise level the physical discomfort starts?

What are the harmful effects of noise pollution?

How does acid rain affect buildings and soil? 

What is meant by Greenhouse gases?

Name two radioactively active gases.

What is greenhouse flux?

Name the gases that are called greenhouse gases.

Name the group of bacteria that produce methane.

Name the layer of atmosphere in which ozone is present.

What is ozone hole?

Which radiations does ozone absorb?

How does depletion of ozone affect humans?

What is effect of global warming on sea level?

Name the scientists who got Nobel prize for discovery related to ozone destruction.

A crane had DDT level as 5 ppm in its body. What would happen to the population of such birds? Explain giving reasons.

Explain the cause of algal bloom in a water body. How does it affect an ecosystem?

Name some sources of air pollution.

What is the effect of hydrocarbons on humans.

What is the effect of sulphur dioxide pollutants on humans.

What is photochemical smog?

Give the reactions involved in the formation of smog?

How does acid rain affect buildings and soil? 

What is the function of electric precipitator?

Why is CNG a better fuel than petrol?