Detailed explanations in West Bengal Board Class 10 Life Science Book Solutions Chapter 5C Environment and Human Population offer valuable context and analysis.
WBBSE Class 10 Life Science Chapter 5C Question Answer – Environment and Human Population
Short Answer Type Questions : 2 Marks
Question 1.
What environmental damage are caused by mercury poliution? What are the main sources of mercury pollution?
Answer:
Mercury is a metal that when present in the water of rivers, lakes and seas contaminates fish, crustaceans, molluscs and other living organisms. The mercury accumulates along the food chain and, in each following trophic level, the amount of the metal within the individuals is higher. When humans eat contaminated animals, they also become contaminated and severe nervous system injuries may result from it. The main sources of mercury pollution are gold mining and the use of substances derived from it in industry and agriculture.
Question 2.
Besides mercury, which other heavy metals cause toxic pollution?
Answer:
Examples of other heavy metals that cause toxic pollution are lead, cadmium and chromium.
Question 3.
What are persistent organic poliutants (POPs)?
Answer:
POPs, or persistent organic pollutants, are toxic substances formed from organic compounds. POPs are produced in several industrial processes, such as the production of PVC, paper whitened by chlorine, herbicides, insecticides and fungicides, as well as in the incineration of waste. Examples of POPs are dioxins, furanes, chlordane, DDT, dieldrin, heptachlor, toxaphene and hexachlorobenzene.
POPs are toxic and highly harmful since, like the heavy metals, they are bioaccumulative, meaning that they are not broken down by the body and accumulate even more in each following trophic level of the food chain. In humans, POPs can cause cancer and nervous, immune and reproductive disorders.
Question 4.
Is the upward movement of warm air good or bad for the dissipation of pollutants?
Answer:
The upward movement of warm air is a natural method of dispersing pollutants. The air near the ground is hotter because the sun heats the soil and the soil heats the air nearby. Since it is less dense, the warm air tends to move towards higher and colder strata of the atmosphere. Such movement helps to disperse pollutants.
Question 5.
Why does thermal inversion increase air pollution? What harm can thermal inversion cause to humans?
Answer:
Thermal inversion confines a layer of pollutants at low altitude, which otherwise would have been dispersed by the natural upward movement of warm air. The solid particles present in the atmosphere cause health problems, such as the exacerbation of asthma and other pulmonary diseases, coughing, respiratory unease and eye discharges. Over time, pollution can also trigger the appearance of cardiovascular and neoplastic diseases.
Question 6.
What are the health consequences of air pollution?
Answer:
Air pollution increases the risk of respiratory and heart disease in the population. Both short and long term exposure to air pollutants have been associated to health impacts. More severe impacts affect people who are already ill. Children, the elderly and poor people are more susceptible.
Question 7.
What is pathogen pollution?
Answer:
Pathogen pollution refers to the introduction of disease-causing microbes(pathogens) and/or their hosts (infected individuals) to new locations around the world. European bird species, including pigeons and the house sparrow, for example, introduced West Nile virus to the United States.
Question 8.
What is an emerging infectious disease (EID)?
Answer:
EIDs include diseases that have jumped from wildlife populations to humans, diseases that have become more frequent, and diseases that are entirely new to science. Examples of EIDs include HIV/AIDS, West Nile virus, and SARS. Lung diseases are some of the most common medical conditions in the world. Tens of millions of people suffer from lung disease in the U.S. Smoking, infections, and genetics are responsible for most lung diseases. The lungs are part of a complex apparatus, expanding and relaxing thousands of times each day to bring in oxygen and expel carbon dioxide. Lung disease can result from problems in any part of this system.
Question 9.
Write the health effect on air pollution.
Answer:
Air Pollution Effects :
- Reduced lung functioning
- Irritation of eyes, nose, mouth and throat
- Asthma attacks
- Respiratory symptoms such as coughing and wheezing
- Increased respiratory disease such as bronchitis
- Reduced energy levels
- Headaches and dizziness
- Disruption of endocrine, reproductive and immune systems
- Neurobehavioral disorders
- Cardiovascular problems
- Cancer
- Premature death.
Question 10.
Write the health effect on water pollution.
Answer:
Water Pollution Effects :
- Waterborne diseases like typhoid,jaundice,cholera
- Hepatitis, encephalitis, gastroenteritis, diarrhoea, vomiting, and stomach aches
- Cancer, including prostate cancer and non-Hodgkin’s lymphoma
- Hormonal problems that can disrupt reproductive and developmental processes
- Damage to the nervous system
- Liver and kidney damage
- Damage to the DNA
Question 11.
Write the health effect on soil pollution.
Answer:
Soil Pollution Effects :
- Lead in soil is especially hazardous for young children causing developmental damage to the brain
- Mercury can increase the risk of kidney damage; cyclodienes can lead to liver toxicity
- Causes neuromuscular blockage as well as depression of the central nervous system
- Also causes headaches, nausea, fatigue, eye irritation and skin rash
- Causes cancers including leukaemia
Long Answer Type Questions : 5 Marks
Question 1.
What do you mean by overpopulation? Write its causes.
Overpopulation
Answer:
Overpopulation is an undesirable condition where the number of existing human population exceeds the carrying capacity of Earth.Overpopulation is caused by number of factors. Reduced mortality rate, better medical facilities, depletion of precious resources are few of the causes which results in overpopulation. It is possible for a sparsely populated area to become densely populated if it is not able to sustain life.
Causes of Overpopulation
Decline in the Death Rate : At the root of overpopulation is the difference between the overall birth rate and death rate in populations. If the number of children born each year equals the number of adults that die, then the population will stabilize.
Better Medical Facilities : Following this came the industrial revolution. Technological advancement was perhaps the biggest reason why the balance has been permanently disturbed. Science was able to produce better means of producing food, which allowed families to feed more mouths.
More Hands to Overcome Poverty : For thousands of years, a very small part of the population had enough money to live in comfort. The rest faced poverty and would give birth to large families to make up for the high infant mortality rate.
Families that have been through poverty, natural disasters or are simply in need of more hands to work are a major factor for overpopulation.
Technological Advancement in Fertility Treatment : With latest technological advancement and more discoveries in medical science, it has become possible for couple who are unable to conceive to undergo fertility treatment methods and have their own babies.
Immigration : Many people prefer to move to develop countries like US, UK, Canada and Australia where best facilities are available in terms of medical, education, security and employment. The end result is that those people settle over there and those places become overcrowded.
Lack of Family Planning : Most developing nations have large number of people who are illiterate, live below the poverty line and have little or no knowledge about family planning. Getting their children married at an early age increase the chances of producing more kids.
Question 2.
Write the effects and solution of overpopulation.
Answer:
Effects of Overpopulation
Depletion of Natural Resources : The effects of overpopulation are quite severe. The first of these is the depletion of resources. The Earth can only produce a limited amount of water and food, which is falling short of the current needs. Most of the environmental damage being seen in the last fifty odd years is because of the growing number of people on the planet.
Degradation of Environment : With the overuse of coal, oil and natural gas, it has started producing some serious effects on our environment. Rise in the number of vehicles and industries have badly affected the quality of air. Rise in amount of CO2 emissions leads to global warming. Melting of polar ice caps, changing climate patterns, rise in sea level are few of the consequences that we might we have to face due to environment pollution.
Conflicts and Wars : Overpopulation in developing countries puts a major strain on the resources, it should be utilizing for development. Conflicts over water are becoming a source of tension between countries, which could result in wars. It causes more diseases to spread and makes them harder to control. Starvation is a huge issue facing the world and the mortality rate for children is being fuelled by it. Poverty is the biggest hallmark we see when talking about overpopulation.
Rise in Unemployment : When a country becomes overpopulated, it gives rise to unemployment as there fewer jobs to support large number of people. Rise in unemployment gives rise to crime as people will steal various items to feed their family and provide them basic amenities of life.
High Cost of Living: As difference between demand and supply continues to expand due to overpopulation, it raises the prices of various commodities including food, shelter and healthcare. This means that people have to pay more to survive and feed their families.
Solutions to Overpopulation
Better Education : One of the first measures is to implement policies reflecting social change. Educating the masses helps them understand the need to have one or two children at the most. Families that are facing a hard life and choose to have four or five children should be discouraged. Family planning and efficient birth control can help in women making their own reproductive choices.
Making People Aware of Family Planning : As population of this world is growing at a rapid pace, raising awareness among people regarding family planning and letting them know about serious after effects of overpopulation can help curb population growth.
Tax Benefits or Concessions : Government of various countries might have to come with various policies related to tax exemptions to curb overpopulation. One of them might be to waive of certain part of income tax or lowering rates of income tax for those married couples who have single or two children.
Knowledge of Sex Education : Imparting sex education to young kids at elementary level should be must. Most parents feel shy in discussing such things with their kids which result in their children going out and look out for such information on internet or discuss it with their peers. Mostly, the information is incomplete which results in sexually active teenagers unaware of contraceptives and embarrassed to seek information about same. It is therefore important for parents and teachers to shed their old inhibitions and make their kids or students aware of solid sex education.
Question 3.
Describe about the Lung Diseases Affecting the Airways
Answer:
The trachea (windpipe) branches into tubes called bronchi, which in turn branch to become progressively smaller tubes throughout the lungs.
Diseases that affect the airways include :
Asthma : The airways are persistently inflamed and may occasionally spasm, causing wheezing and shortness of breath. Allergies, infections, or pollution can trigger asthma’s symptoms.
Chronic obstructive pulmonary disease (COPD) : Lung conditions defined by an inability to exhale normally, which causes difficulty breathing.
Chronic bronchitis : A form of COPD characterized by a chronic productive cough.
Emphysema : Lung damage allows air to be trapped in the lungs in this form of COPD. Difficulty blowing air out is its hallmark.
Acute bronchitis : A sudden infection of the airways, usually by a virus.
Cystic fibrosis : A genetic condition causing poor clearance of mucus from the bronchi. The accumulated mucus results in repeated lung infections.
Question 4.
Describe about the Lung Diseases affecting the air sacs (Alveoli).
Answer:
The airways eventually branch into tiny tubes (bronchioles) that dead-end into clusters of air sacs called alveoli. These air sacs make up most of the lung tissue. Lung diseases affecting the alveoli include :
Pneumonia : An infection of the alveoli, usually by bacteria.
Tuberculosis: A slowly progressive pneumonia caused by the bacteria Mycobacterium tuberculosis.
Emphysema results from damage to the fragile connections between alveoli. Smoking is the usual cause. (Emphysema also limits air flow, affecting the airways as well.)
Pulmonary edema : Fluid leaks out of the small blood vessels of the lung into the air sacs and the surrounding area. One form is caused by heart failure and back pressure in the lungs’ blood vessels ; in another form, direct injury to the lung causes the leak of fluid.
Lung cancer has many forms, and may develop in any part of the lungs. Most often this is in the main part of the lung, in or near the air sacs. The type, location, and spread of lung cancer determine the treatment options.
Acute respiratory distress syndrome (ARDS): Severe, sudden injury to the lungs caused by a serious illness. Life support with mechanical ventilation is usually needed to survive until the lungs recover.
Pneumoconiosis : A category of conditions caused by the inhalation of a substance that injures the lungs. Examples include black lung disease from inhaled coal dust and asbestosis from inhaled asbestos dust.
Question 5.
Describe about the Lung Diseases affecting the interstitium.
Answer:
The interstitium is the microscopically thin, delicate lining between the lungs’ air sacs (alveoli). Tiny blood vessels run through the interstitium and allow gas exchange between the alveoli and the blood. Various lung diseases affect the interstitium:
Interstitial lung disease (ILD) : A broad collection of lung conditions affecting the interstitium. Sarcoidosis,idiopathic pulmonary fibrosis, and autoimmune disease are among the many types of ILD.
Pneumonias and pulmonary edemas can also affect the interstitium.
Question 6.
Describe about the Lung Diseases affecting blood vessels.
Answer:
The right side of the heart receives low-oxygen blood from the veins. It pumps blood into the lungs through the pulmonary arteries. These blood vessels can suffer from disease, as well.
Pulmonary Embolism (PE) : A blood clot (usually in a deep leg vein,deep vein thrombosis) breaks off, travels to the heart, and is pumped into the lungs. The clot lodges in a pulmonary artery, often causing shortness of breath and low blood oxygen levels.
Pulmonary hypertension : Various conditions can lead to high blood pressure in the pulmonary arteries. This can cause shortness of breath and chest pain. When no cause is identified, the condition is called idiopathic pulmonary arterial hypertension.
Question 7.
Describe about the Lung Diseases affecting the pleura.
Answer:
The pleura is a thin lining that surrounds the lung and lines the inside of the chest wall. A tiny layer of fluid allows the pleura on the lung’s surface to slide along the chest wall with each breath. Lung diseases of the pleura include :
Pleural effusion : Fluid collects in the normally tiny pleura space between the lung and the chest wall. Pneumonia or heart failure is usually responsible. If large, pleural effusions can impair breathing, and should be drained.
Pneumothorax : Air may enter the space between the chest wall and the lung, collapsing the lung. To remove the air, a tube is typically inserted through the chest wall.
Mesothelioma : A rare form of cancer that forms on the pleura. Mesothelioma tends to emerge several decades after asbestos exposure.
Question 8.
Describe about the Lung Diseases affecting the chest wall.
Answer:
The chest wall also plays an important role in breathing. Muscles connect the ribs to each other, helping the chest to expand. The diaphragm descends with each breath in, also causing chest expansion.
Obesity hypoventilation syndrome : Extra weight on the chest and abdomen makes it difficult for the chest to expand. Serious breathing problems can result.
Neuromuscular disorders : Poor function in the nerves controlling the respiratory muscles causes difficulty of breathing. Amyotrophic lateral sclerosis and myasthenia gravis are examples of neuromuscular lung disease.
Multiple Choice Questions : 1 Mark
Question 1.
Who among the following are resource creating factors as well as resources themselves?
(a) Animals
(b) Plants
(c) Human beings
(d) Nature
Answer:
(c) Human beings
Question 2
In which of the following instances does a natural event like a flood or Tsunami become a “disaster”?
(a) Only when they affect a crowded village or town
(b) When the natural events are of great intensity
(c) When they happen in the environment
(d) When they affect large uninhabited areas
Answer:
(a) Only when they affect a crowded village or town
Question 3.
The numbers, distribution, growth and characteristics of which of the following provide the basic background for understanding and appreciating all aspects of the environment?
(a) Natural resource
(b) Population
(c) Flora
(d) Fauna
Answer:
(b) Population
Question 4.
Why is it important to know how many people are there in a country, where do they live, how and why their numbers are increasing and what are their characteristics?
(a) Population is the pivotal element in social studies
(b) To exploit the natural resources of the country
(c) Human beings are producers and consumers of resources
(d) None of these
Answer:
(c) Human beings are producers and consumers of resources
Question 5.
From which of the following do we get information regarding the population of our country?
(a) Text books
(b) Survey of India
(c) Census
(d) Geological Survey of India
Answer:
(c) Census
Question 6.
Which of the following is a major concern of study about the population of a country?
(a) Population size and distribution
(b) Population growth and processes of population change
(c) Characteristics or qualities of the population
(d) All of these
Answer:
(d) All of these
Question 7.
The average number of persons per unit area, such as a square kilometre, is termed as which of the following?
(a) Population distribution
(b) Population density
(c) Absolute population
(d) Population growth
Answer:
(b) Population density
Question 8.
Which of the following reasons is responsible for uneven population distribution in India?
(a) Variations in topography or relief in different parts of India
(b) Variations in climate and rainfall distribution
(c) Variations in the rate of industrialisation and urbanisation
(d) All of the above
Answer:
(d) All of the above
Question 9.
When did the National Population Policy come into effect?
(a) 2001
(b) 1947
(c) 1952
(d) 2000
Answer:
(d) 2000
Question 10.
The unfavourable alteration of environment due to human activities is termed as
(a) ecological disturbance
(b) catastrophe
(c) ecological degradation
(d) pollution
Answer:
(d) pollution
Question 11.
Which of the following is the best indicator of SO2 pollution
(a) bryophyte
(b) pteridophyte
(c) lichen
(d) algae
Answer:
(c) lichen
Question 12.
Heavy dust can cause
(a) leaf blights
(b) opening of stomata
(c) closure of stomata
(d) browning of leaves
Answer:
(c) closure of stomata
Question 13.
Which of the following is the major cause of pollution
(a) Plants
(b) man
(c) fungi
(d) hydrocarbon gases
Answer:
(d) hydrocarbon gases
Question 14.
Minamata disease was caused by pollution of water by
(a) mercury
(b) lead
(c) tin
(d) methyl isocyanate
Answer:
(a) mercury
Question 15.
BOD stands for
(a) biotic oxidation demand
(b) biological oxidation demand
(c) biological oxygen demand
(d) biochemical oxygen demand
Answer:
(c) biological oxygen demand
Question 16.
A river with high BOD value is
(a) highly polluted
(b) highly clean
(a) highly productive
(d) none of these
Answer:
(a) highly polluted
Question 17.
5 June is observed as
(a) world forest day
(b) world environment day
(a) world wildlife day
(d) world population day
Answer:
(b) world environment day
Question 18.
Cement factory labourers are prone to
(a) leukemia
(b) bone marrow disease
(c) asbestosis
(d) cytosilicosis
Answer:
(d) cytosilicosis
Question 19.
Noise is measured using sound meter and the unit is
(a)) hertz
(b) decibel
(c) joule
(d) sound
Answer:
(b) decibel
Very Short Answer Type Questions : 1 Mark
Question 1.
What is overpopulation?
Answer:
For a period of time, excess population in an area.
Question 2.
Which gas mostly causes global warming?
Answer:
CO2
Question 3.
Which situation causes scarcity of food?
Answer:
Overpopulation.
Question 4.
Mention two situation due to over population.
Answer:
Deforestation, shrinkage of Agricultural land.
Question 5.
Mention two diseases of water borne.
Answer:
Hepatitis, Typhoid.
Question 6.
Name two diseases of food borne,
Answer:
Cholera, Aspergilosis.
Question 7.
Mention two ariborne diseases.
Answer:
Influenza, Pneumonia.
Question 8.
What is the cause of minamata disease?
Answer:
Due to excess amount of mercury.
Question 9.
Name two lung diseases.
Answer:
Asthma, Bronchitis.
Question 10.
Name the agent causing cancer.
Answer:
Carcenogen.
Question 11.
Name two causative agents for lung cancer.
Answer:
Pesticides, Food adulteration, smoke from industry.
Question 12.
Name two agents for Asthma.
Answer:
Pollens, dust, fungus.
Question 13.
Name the disease due to lead pollution.
Answer:
Dislexia.
Question 14.
Name the causative agent of Aspergilosis.
Answer:
Fungus.