Class09 : Population : NCERT Solutions

 

Question 1: Migrations change the number, distribution and composition of the population in

1. The area of departure
2. Both the area of departure and arrival
3. The area of arrival
4. None of the above
   
   Answer: (b) Both the area of departure and arrival

Question 2: A large proportion of children in a population is a result of

1. High birth rates
2. High death rates
3. High life expectancies
4. More married couples
   
   Answer: (a) High birth rates

Question 3: The magnitude of population growth refers to

1. The total population of an area
2. The number of persons added each year
3. The rate at which the population increases
4. The number of females per thousand males
   
   Answer: (b) The number of persons added each year

Question 4: According to the Census 2001, a “literate” person is one who

1. Can read and write his/her name
2. Can read and write any language
3. Is 7 years old and can read and write any language with understanding
4. Knows the 3 ‘R’s (reading, writing, arithmetic)
   
   Answer: (a) Can read and write his/her name

Question 5: Why is the rate of population growth in India declining since 1981?

Answer: The family planning programme helped in increasing the awareness about the benefits of smaller family size. This helped in reducing the rate of population growth in India since 1981.

Question 6: Discuss the major components of population growth.

Answer: Birth rate, death rate and migration are the major components of population growth. A higher birth rate; coupled with a lower death rate leads to population growth. International migration can lead to population growth of more number of people are coming from other countries than the number of people going outside the country.

Question 7: Define age structure, death rate and birth rate.

Answer: Age Structure: Relative percentage of various age groups in the population is called age structure of the population. Age group is generally divided into children (upto 14 years), working age (15 – 59 years) and aged (60 years and above).

Death Rate: The number of deaths per 1000 persons is called death rate.

Birth Rate: The number of live births per 1000 persons is called birth rate.

Question 8: How is migration a determinant factor of population change?

Answer: Migration within the country is called internal migration, while that between two countries is called international migration. Internal migration has no change on population size but it changes the population composition of a particular area. International migration can lead to a growth or degrowth in population; depending on the degree of immigration and emigration.

Question 9: Distinguish between population growth and population change.

Answer: Population growth is about increase or decrease in the population. Population change is about changes in population composition; like age structure, sex ratio, literacy rate, occupational structure, etc.

Question 10: What is the relation between occupational structure and development?

Answer: Occupational structure greatly affects the development of a country. A large portion of the Indian population is still dependent on the primary sector for employment; which is one of the reasons for lack of development in India. Examples of developed nations suggest that when a greater portion of population engages in secondary and tertiary activities, it leads to proper development.

Question 11: What are the advantages of having a healthy population?

Answer: A healthy population helps in building a productive workforce for the country. Even the non-productive age group needs to be healthy to reduce the burden of healthcare. Healthy children would grow into healthy adults and would be able to contribute better in the economy. Healthy elders would mean less drain on the resources.

Question 12: What are the significant features of the National Population Policy 2000?

Answer: NPP 200 has put special emphasis on the adolescent population. Focus is given to special nutritional needs of the adolescents. Awareness programmes are conducted to increase awareness about STDs, unwanted pregnancies, child marriage, risks of unprotected sex, etc.

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Class09 : Climate : NCERT Solutions

 Question 1: Which one of the following places receives the highest rainfall in the world ?

1. Silchar
2. Cherrapunji
3. Mawsynram
4. Guwahati
   
   Answer: (c) Mawsynram

Question 2: The wind blowing in the northern plains in summers is known as:

1. Kal Baisakhi
2. Trade Wind
3. Loo
4. None of the above
   
   Answer: (c) Loo

Question 3: Which one of the following causes rainfall during winters in north-western part of India.

1. Cyclonic depression
2. Western disturbances
3. Retreating monsoon
4. Southwest monsoon
   
   Answer: (b) Western disturbances

Question 4: Monsoon arrives in India approximately in:

1. Early May
2. Early June
3. Early July
4. Early August
   
   Answer:(b) Early June

Question 5: Which one of the following characterises the cold weather season in India?

1. Warm days and warm nights
2. Warm days and cold nights
3. Cool days and cold nights
4. Cold days and warm nights
   
   Answer: (c) Cool days and cold nights

Question 6: What are the controls affecting the climate of India ?

Answer: Latitude, Altitude and Pressure and Winds are the main factors which affect the climate of India.

Question 7: Why does India have a monsoon type of climate ?

Answer: India comes in the Inter Tropical Convergence Zone (ITCZ). This fact; in association with various other factors, like the El Nino, Jet Stream and Coriolois Force are the reasons for monsoon type of climate in India.

Question 8: Which part of India does experience the highest diurnal range of temperature and why ?

Answer: Northwestern part of India experiences the highest diurnal range of temperature. This happens because of the presence of the Thar Desert and also because this region does not have the moderating influence of the ocean.

Question 9: Which winds account for rainfall along the Malabar coast ?

Answer: Monsoon winds

Question 10: What are Jet streams and how do they affect the climate of India ?

Answer: Fast flowing and narrow air currents are called jet streams. The streams flow at high altitudes (about 12,000 feet) in the troposphere. The westerly jet streams are responsible for western cyclonic disturbances in the north and north-western parts of India. The subtropical westerly jet stream moves north of the Himalayas with the apparent movement of the sun. The tropical jet stream (an easterly jet stream) blows over the Indian Peninsula; approximately over 14° north during the summer months.

Question 11: Define monsoons. What do you understand by “break” in monsoon ?

Answer: The seasonal reversal in wind direction during a year is called monsoon. Monsoon tends to have ‘breaks’ in rainfall; which means that there are wet and dry spells in between. The monsoon rains take place only for a few days at a time and then come the rainless intervals.

Question 12: Why is the monsoon considered a unifying bond ?

Answer: Although there are wide variations in weather patterns across India, the monsoon brings some unifying influences on India. The Indian landscape, its flora and fauna, etc. are highly influenced by the monsoon. The entire agricultural calendar in India is governed by the monsoon. Most of the festivals in India are related to agricultural cycle. These festivals may be known by different names in different parts of the country, but their celebration is decided by the monsoon. It is also said that the river valleys which carry the rainwater also unite as a single river valley unit. Due to these reasons, monsoon is often a great unifying factor in India.

Question 13: Why does the rainfall decrease from the east to the west in Northern India ?

Answer: The Bay of Bengal branch of the monsoon winds moves towards northeast and return westwards covering the northern plains. While they move towards west, their moisture contains tends to reduce with subsequent rains. Hence the rainfall decreases from east to west in northern India.

Question 14: Give reasons as to why

1. Seasonal reversal of wind direction takes place over the Indian subcontinent?
   
   Answer: Seasonal reversal of wind direction over the Indian subcontinent takes place due to pressure differential. El Nino has major role to play in the seasonal reversal of wind direction over the Indian subcontinent.
   
   
2. The bulk of rainfall in India is concentrated over a few months.
   
   Answer: The monsoon begins from the first week of June and advances quite rapidly to cover almost the whole country by mid-July. Hence, the bulk of rainfall in India is concentrated over the months of a few months; mainly June to August.
   
   
3. The Tamil Nadu coast receives winter rainfall.
   
   Answer: The Tami Nadu coast receives winter rainfall because of movement of low-pressure conditions to the Bay of Bengal.
   
   
4. The delta region of the eastern coast is frequently struck by cyclones.
   
   Answer: The Bay of Bengal is the centre of various pressure changes and hence there is always a chance of development of cyclone. Due to this, the delta region of the eastern coast is frequently struck by cyclones.
   
   
5. Parts of Rajasthan, Gujarat and the leeward side of the Western Ghats are drought-prone.
   
   Answer: These parts fall in the rain shadow area of the Aravalli. Hence, they are drought prone.

Question 15: Describe the regional variations in the climatic conditions of India with the help of suitable examples.

Answer: Indian Peninsular shows wide variations in climatic conditions across various regions. For example; during winter season, the temperature goes into negative in the Himalayan region. In the northwestern India, temperatures can range between zero degree to 15°C during winter. During the same season, the temperature in Chennai remains a comfortable 25°C. The same variation can be seen in summer as well, while the temperature in Rajasthan can hover around 47°C, it is a comfortable 30°C in Chennai.

Question 16: Discuss the mechanism of monsoons.

Answer: The low-pressure condition over the northern plains intensifies by the beginning of June. It attracts the trade winds from the southern hemisphere. These south-east trade winds cross the equator and blow in a south-westerly direction to enter the Indian peninsula as the south-west monsoon. These winds bring abundant moisture to the subcontinent.

Question 17: Give an account of weather conditions and characteristics of the cold season.

Answer: The temperature ranges between 10°-15°C in the northern plains. The weather is usually marked by clear sky, low temperatures and low humidity and feeble variable winds. The inflow of the cyclonic disturbances from the west and the northwest is a characteristic feature of the cold weather over the northern plains. These low-pressure systems originate over the Mediterranean Sea and Western Asia and move into India. They cause winter rains over the plains and snowfall in the mountains.

Question 18: Give the characteristics and effects of the monsoon rainfall in India.

Answer: Monsoon tends to have ‘breaks’ in rainfall; which means that there are wet and dry spells in between. The monsoon is famous for its uncertainties. It may cause heavy floods in one part of the country, and may be responsible for droughts in other part. Because of its uncertain behaviour, it sometimes disturbs the farming schedule in India. This affects millions of farmers all over the country.

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Class09 : Natural Vegetation and Wildlife : NCERT Solutions

Question 1 To which one of the following types of vegetation does rubber belong to?

1. Tundra
2. Himalayan
3. Tidal
4. Tropical Evergreen
   
   Answer: (d) Tropical evergreen

Question 2 Cinchona trees are found in the areas of rainfall more than

1. 100 cm
2. 70 cm
3. 50 cm
4. Less than 50 cm
   
   Answer: (a) 100 cm

Question 3 In which of the following state is the Simlipal bio-reserve located ?

1. Punjab
2. Delhi
3. Orissa
4. est Bengal
   
   Answer: (d) West Bengal

Question 4 Which one of the following bio-reserves of India is not included in the world network of bioreserve ?

1. Manas
2. Gulf of Mannar
3. Nilgiri
4. Nanda Devi
   
   Answer: (a) Manas

Question 5: Define an ecosystem.

Answer: All the plants and animals in an area are interdependent on each other. The plants and animals; alongwith their physical environment make the ecosystem.

Question 6: What factors are responsible for the distribution of plants and animals in India?

Answer: Relief (Land and soil) and Climate (Temperature, humidity, photoperiod and precipitation) are the factors which are responsible for the distribution of plants and animals in India.

Question 7: What is a bio-reserve? Give two examples.

Answer: A biosphere reserve is an area proposed by its residents, ratified by a national committee, and designated by UNESCO’s Man and Biosphere (MAB) program, which demonstrates innovative approaches to living and working in harmony with nature. (ref: Wikipedia)

Question 8: Name two animals having habitat in tropical and montane type of vegetation.

Answer: Tropical (Elephant, deer) and Montane (yak, snow leopard)

Question 9: Distinguish between

1. Flora and fauna
   
   Answer: Plant species comprise the flora, while animal species comprise the fauna.
   
   
2. Tropical Evergreen and Deciduous forests
   
   Answer: Trees of evergreen forests do not shed their leaves at a fixed time in a year, while trees of deciduous forest shed their leaves at a fixed time in a year.

Question 10: Name different types of Vegetation found in India and describe the vegetation of high altitudes.

Answer: There are five major types of vegetation in India: Tropical Rainforests, Tropical Deciduous Forests, Tropical Thorn Forests and Scrubs, Montane Forests and Mangrove Forests.

Montane Forest: The forests in the mountainous areas are called montane forest. These forests are mainly found along the southern slopes of the Himalayas and at high altitudes in southern and north-eastern India. Kashmir stag, spotted deer, wild sheep, jack rabbit, Tibetan antelope, yak, snow leopard, squirrels, Shaggy horn wild ibex, bear, rare red panda, sheep and goats are the common animals in these forests.

Question 11: Quite a few species of plants and animals are endangered in India. Why ?

Answer: Large scale deforestation has reduced the natural habitat of many plants and animals. Due to this, many species of plants and animals are endangered in India.

Question 12: Why has India a rich heritage of flora and fauna?

Answer: India has a variety of climatic conditions; like tropical, subtropical, desert and mountainous. Due to this, there are enough habitats for a large variety of flora and fauna. Due to this, India has a rich heritage of flora and fauna.

Thank you very much for reading carefully, if you have any other questions, you can share it with us through comments, if this information was important to you, please let us know through comments.

Please do comment and share.

Thank You.