Q1: What is ‘water cycle’?
Ans: Water is in constant motion, cycling through the oceans, the air, the land and back again, through the processes of evaporation, precipitation and run-off. This is referred to as the ‘water cycle’.
Q2: What are the uses of water resources?
Ans: Humans use huge amounts of water not only for drinking and washing but also in the process of production. Water for agriculture, industries, generating electricity through reservoirs of dams are the other usages.
Q3: Which countries in the world are facing water shortage?
Ans: There is scarcity of water in many regions of the world. Most of Africa, West Asia, South Asia, parts of western USA, north-west Mexico, parts of South America and entire Australia are facing shortages in fresh water supply.
Q4: What are landslides and how do they occur?
Ans: Landslides are simply defined as the mass movement of rock, debris or earth down a slope. They often take place in conjunction with earthquakes, floods and volcanoes. A prolonged spell of rainfall can cause heavy landslide that can block the flow of river for quite some time.
Q5: What are the reasons for the degradation of the soil?
Ans: Soil erosion and depletion are the major threats to soil as a resource. Both human and natural factors can lead to degradation of soils. Factors which lead to soil degradation are deforestation, overgrazing, overuse of chemical feritilisers or pesticides, rain wash, landslides and floods.
Q6: Name any two steps that government has taken to conserve plants and animals.
Ans: Two steps that government has taken to conserve plants and animals are:
Q7: In what forms is freshwater found on the earth?
Ans: Fresh water accounts for only about 2.7 per cent. Nearly 70 per cent of this occurs as ice sheets and glaciers in Antarctica, Greenland and mountain regions. Due to their location they are inaccessible. Only 1 per cent of freshwater is available and fit for human use. It is found as ground water, as surface water in rivers and lakes and as water vapour in the atmosphere.
Q8: Why there is uneven distribution of population in different parts of the world?
Ans: The uneven distribution of population in different parts of the world is mainly due to varied characteristics of land and climate. The rugged topography, steep slopes of the mountains, low-lying areas susceptible to water logging, desert areas, and thick forested areas are normally sparsely populated or uninhabited. Plains and river valleys offer suitable land for agriculture. Hence, these are the densely populated areas of the world.
Q9: Why is wildlife important to us?
Ans: Wildlife is important to us because
Q10: “Vegetation and wildlife are valuable resources.” Comment
Ans: Vegetation and wildlife are valuable resources.
Q11: Suggest some methods of soil conservation.
Ans: Some methods of soil conservation are
Q12: What are the major factors affecting soil formation?
Ans: The major factors of soil formation are the nature of the parent rock and climatic factors. Other factors are the topography, role of organic material and time taken for the composition of soil formation.
Q13: What do you mean by private land and community land?
Ans: Private land is owned by individuals whereas, community land is owned by the community for common uses like collection of fodder, fruits, nuts or medicinal herbs. These community lands are also called common property resources.
Q14: What human factors determine land use pattern?
Ans: The use of land is determined by physical factors such as topography, soil, climate, minerals and availability of water. Human factors such as population and technology are also important determinants of land use pattern.
Q15: Why water availability per person in India is declining?
Ans: Increasing population, rising demands for food and cash crops, increasing urbanisation and rising standards of living are the major factors leading to shortages in supply of fresh water either due to drying up of water sources or water pollution.
Q16: Suggest three ways to conserve water.
Ans: Ways to conserve water:
Q17: What do you know about CITES?
Ans: CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora) is an international agreement between governments. It aims to ensure that international trade in specimens of wild animals and plants does not threaten their survival. Roughly 5,000 species of animals and 28,000 species of plants are protected. Bears, dolphins, cacti, corals, orchids and aloes are some examples.
Q18: How does rainfall affect vegetation?
Ans: In areas of heavy rainfall, huge trees may thrive. The forests are thus associated with areas having abundant water supply. As the amount of moisture decreases the size of trees and their density reduces. In the regions of moderate rainfall short stunted trees and grasses grow forming the grasslands of the world. In dry areas of low rainfall, thorny shrubs and scrubs grow. In such areas plants have deep roots and leaves have thorny and waxy surface to reduce loss of moisture by transpiration.
Q19: What are the factors affecting soil formation?
Ans: Factors affecting soil formation are:
Q20: What are the threats to natural vegetation and wildlife?
Ans: Threats to natural vegetation and wildlife are: