Important Questions: Life on the Earth | Geography Class 11 - Humanities/Arts PDF Download

Very Short Answer Type Questions

Q1: What is ecology?
Ans: Ecology is the science that studies the interaction of organisms with their environment.

Q2: What is ‘Charak Samhita’?
Ans: It is the book of Indian medicine written by Charak, the first century A.D. scholar, who has listed over 200 kinds of animals and, about 340 kinds of plants in this book,

Q3: What is the science of classification of organisms called?
Ans: The science of the classification of organisms is called taxonomy.

Q4: Name the positive biotic interactions.
Ans: Positive biotic interactions include mutualism, where both species benefit, and commensalism, where one species benefits without harming the other.

Q5: Give two examples of fungi.
Ans: Yeast and mushrooms are two examples of fungi.

Q6: What are the major determinants of nature and the extent of a biome?
Ans: Rainfall, temperature range, nature, soil, barriers, latitude, and altitude are the major determinants of the nature and extent of a biome.

Q7: Give some examples of hoofed herbivore species.
Ans: They include zebra, giraffe, elephant, kangaroos, and several kinds of antelopes.

Q8: Name the principal grasslands of the world.
Ans: The principal grasslands of the world include prairies of Canada and the USA, the pampas of South America, the steppes of Europe and Asia, and veldts of Africa.

Short Answer Type Questions

Q9: What kind of animals live in tropical rain forests?
Ans: The animals living in tropical rain forests include monkeys, snakes, ant-eaters, tropical birds, bats, large carnivorous animals, and a variety of fish in the rivers. Of all the species of insects known nearly 70 to S0% occur in the tropical rain forests.

Q10: What kind of plant and animal life is supported by tropical savanna?
Ans: Savannas are characterized by coarse grass and scattered trees on the margins of the tropics where rainfall is seasonal. Wet seasons alternate with dry seasons. Plants and animals are drought-tolerant and do not show much diversity. This biome supports the greatest variety of hoofed herbivore species including the zebra, giraffe, elephant, and several kinds of antelopes. Kangaroos are found in the savannas of Australia.

Q11: Write a note on deciduous forests.
Ans: The deciduous forests are found in the temperate regions of north-central Europe, eastern Asia, and the eastern United States. The annual precipitation ranges between 75-150 cm. With the onset of autumn, most of the trees and shrubs become leafless. The vegetation comprises broad-leaved, hardwood trees such as oak, elm, beech, maple, and hickory. The fauna includes frogs, salamanders, turtles, snakes, lizards, squirrels, rabbits, deer, bears, raccoons, foxes, and songbirds.

Q12: Define ‘ecosystem’ with examples.
Ans: The biotic community, along with the physical environment, forms an interacting system called the ecosystem. An ecosystem can be natural or artificial, temporary or permanent. A large grassland or a forest, a small tract in a forest or a single log, an edge of the pond, a village, an aquarium, or a manned spaceship can all be regarded as ecosystems.

Q13: Explain with examples the role of members of the fungi kingdom of organisms.
Ans: The fungi kingdom includes diverse kinds of multicellular heterotrophic organisms. There are over 100,000 species of fungi. Some are unicellular like yeast, others are complex like mushrooms. The fungi are the major decomposers and their activity is essential for the recycling of inorganic resources in the biosphere.

Q14: What is the hydrologic cycle?
Ans: All living organisms, the atmosphere, and the lithosphere maintain between them a circulation of water in solid, liquid, or gaseous form, referred to as water or hydrologic cycle.

Q15: What is denitrification?
Ans: Herbivorous animals feeding on plants in turn consume some of it. Dead plants and animals, excreted nitrogenous wastes are converted into nitrites by the attachment of bacteria present in the soil. Some bacteria can even convert nitrites into nitrates that can be used again by the green plants. There are still other types of bacteria capable of converting nitrates into free nitrogen, a process known as denitrification.

Long Answer Type Questions

Q16: Describe the functions of various biotic components.
Ans: Various biotic components include producers, herbivores, carnivores, and decomposers. All organisms require energy for their life processes. Food supplies both energy and materials for the sustenance of life. Green plants produce carbohydrates by photosynthesis and also synthesize proteins and fats. The green plants, therefore, are called producers. The animals that consume this energy are called consumers.
The herbivores like cattle, deer, and goats derive their food or energy directly from plants and are called the first-order consumers. The carnivores like tiger and lion depend on herbivores for their food and energy and are therefore called the secondary or second-order consumers. The non-green organisms like fungi and some bacteria, which do not produce their own food, live on the dead and decaying plants or animals and are consumers of a special type called decomposers.

Q17: Describe the carbon cycle in brief.
Ans: Carbon is one of the basic elements of all living organisms. It forms the basic constituent of all organic compounds. The biosphere contains over half a million carbon compounds. The carbon cycle is mainly the conversion of carbon dioxide. This conversion is initiated by the fixation of carbon dioxide from the atmosphere through photosynthesis. Such conversion results in the production of carbohydrates, glucose that may be converted to other organic compounds such as starch, cellulose, etc. Here, some of the carbohydrates are utilized directly by the plant itself. During this process, more carbon dioxide is generated and is released through its leaves or roots during the day. The remaining unutilized carbohydrates become part of the plant tissue.
The plant tissues are either eaten by the herbivorous animals or get decomposed by micro-organisms. The herbivores convert some of the consumed carbohydrates into carbon dioxide for release into the air through respiration. The micro-organisms decompose the remaining carbohydrates after the animal dies. The carbohydrates that are decomposed get oxidized into carbon dioxide and are returned back to the atmosphere.

Q18: “Food chains are not isolated linear chains of trophic levels.” Comment.
Ans: In nature, the food relationship cannot be explained only in terms of a single food chain. A herbivore consumes many types of plants or plant products. Many kinds of animals, other than tiger, derive food from herbivorous animals. Ticks and mites, leeches, and blood-sucking insects are dependent on herbivores and even on carnivores. Thus, food chains are not isolated linear chains of trophic levels.
Depending upon the availability and choice of food, different organisms at each level have a food relationship with more than one organism at the lower levels. A rat, for example, feeds on various kinds of stem, roots, fruits, and grains. In turn, it is consumed by a snake which is eaten by a falcon. The snakes feed on both, frogs and rats. Then, a network of food chains exist, which is called a food web. The food web becomes more complicated when taste and preference, availability, and compulsion are involved.

Q19: Distinguish between Taiga and Tundra biome.
Ans: Taiga and tundra are two distinct biomes characterized by different climates, vegetation, and geographic locations:
Taiga:

• Climate: The taiga, also known as the boreal forest, is characterized by cold winters and relatively mild summers. It experiences a subarctic or cold-temperate climate with freezing winters and short, cool summers.
• Vegetation: The dominant vegetation in the taiga consists of coniferous trees such as spruce, pine, and fir. These trees have needle-like leaves and are adapted to withstand cold and snowy conditions.
• Geographic Distribution: Taiga biomes are typically found in the northern hemisphere, spanning regions like Canada, Alaska, Russia, Scandinavia, and northern parts of Asia.

Tundra:

• Climate: The tundra biome is characterized by extremely cold temperatures year-round. It experiences an Arctic climate with very short summers and long, harsh winters.
• Vegetation: Tundra vegetation is adapted to the cold and includes low-growing plants like mosses, lichens, and hardy shrubs. Trees are virtually absent due to the extreme cold and permafrost (permanently frozen ground).
• Geographic Distribution: Tundra regions are found at high latitudes near the Arctic Circle in the Northern Hemisphere and at high altitudes in some mountain ranges. They can be found in places like northern Canada, Alaska, Siberia, and parts of Scandinavia.

Q20: What do you understand by biogeochemical cycles?
Ans: Biogeochemical cycles are natural processes that involve the transfer and transformation of matter within the Earth's ecosystems. These cycles, which include the carbon cycle, nitrogen cycle, water cycle, phosphorus cycle, and various others, describe how essential elements and compounds necessary for life move through the atmosphere, hydrosphere, lithosphere, and biosphere.
In biogeochemical cycles, elements and compounds are exchanged between living organisms, the atmosphere, and the Earth's crust. Biological processes, such as photosynthesis, respiration, and decomposition, play a crucial role in these cycles. Physical and chemical processes, such as weathering, erosion, and precipitation, also contribute to the movement and transformation of these substances.
These cycles are essential for sustaining life on Earth as they regulate the availability of nutrients and elements necessary for the growth of organisms. They also influence the composition and functioning of ecosystems, the quality of air and water, and the overall health of the planet. The balance and efficiency of biogeochemical cycles are critical for maintaining the stability and sustainability of ecosystems.