Welcome to Chapter 16 of your 10th-grade Biology journey, where we will explore the intricate relationship between “Man and His Environment.” In this captivating chapter, we will delve into the dynamic interplay between human beings and the world they inhabit. From the air we breathe to the ecosystems we share, this chapter will unveil the profound impact that our actions have on the delicate balance of nature.
Join us as we uncover the ways in which humans influence their surroundings and, in turn, are shaped by the environment they call home. Get ready to broaden your horizons and gain a deeper understanding of the responsibilities and opportunities that arise from our connection to the world around us.
Unit 16 Man and his Environment Long Questions
Unit 16 Man and his Environment MCQ’s
- 10th Class Pak Study Textbook
- 9th and 10th Class General Science Textbook
- Chapter No. 9 Notes 10th Chemistry
- Biology 10th Class Past Papers
- English Past Papers of 10th Class
Unit 16 Man and his Environment Short Questions
What is ecology?
Ecology is the study of the interrelationship between organisms and their environment.
What are the levels of biological selection in ecology?
The levels of organization in ecology range from organism to biosphere.
Define population in ecology.
A population refers to a group of organisms of the same species inhabiting a specific geographical area at a particular time.
What is a community in ecology?
A community is a collection of all the populations that live in a habitat and interact with one another.
What is an ecosystem?
An ecosystem is a self-sufficient unit of the environment formed by interactions between its biotic community and abiotic components.
Give examples of natural ecosystems.
Examples of natural ecosystems include a pond, a lake, and a forest.
What is the biosphere?
The biosphere encompasses all ecosystems on Earth and includes all regions where organisms live, ranging from the oceans’ floor to the highest mountains.
What are the abiotic components of an ecosystem?
Abiotic components are non-living factors in an ecosystem, including light, air, water, soil, basic elements, and compounds.
Who are producers in an ecosystem?
Producers are autotrophs like plants, algae, and photosynthetic bacteria that can synthesize complex organic compounds (food) from inorganic raw materials.
What are primary consumers?
Primary consumers, also known as herbivores, directly feed on plants or plant products.
Differentiate between primary, secondary, and tertiary carnivores.
Primary carnivores (secondary consumers) feed on herbivores, secondary carnivores (tertiary consumers) feed on primary carnivores, and tertiary carnivores are top carnivores that feed on secondary carnivores.
What are decomposers in an ecosystem?
Decomposers, also known as reducers, break down complex organic compounds in dead plant and animal matter into simple compounds through digestion. Bacteria and fungi are principal decomposers in the biosphere.
What is a trophic level in an ecosystem?
A trophic level is a level within a food chain where organisms occupy a specific position based on their feeding habits.
Explain the unidirectional flow of energy in an ecosystem.
Energy in an ecosystem flows from one trophic level to the next, starting with producers. Producers obtain solar energy through photosynthesis, which is then transferred to herbivores, carnivores, and decomposers as organisms are consumed. The flow of energy follows a specific direction, from the Sun to producers and through the various consumers.
What is the primary source of energy for all ecosystems?
The primary source of energy for all ecosystems is the Sun.
How do herbivores and carnivores obtain and use energy in an ecosystem?
Herbivores obtain energy by consuming producers (plants) and convert it into mechanical and heat energy during their metabolic activities. Carnivores obtain energy by consuming herbivores, utilizing it for body activities and storing the excess in their tissues.
Explain the concept of a food chain.
A food chain is a series of organisms within an ecosystem where each organism feeds on the one before it and is, in turn, fed by the one after it. It starts with a plant (producer) that is consumed by a primary consumer, which is then consumed by a secondary consumer, and so on.
How does a food web differ from a food chain?
A food web is a network of interconnected food chains within an ecosystem, showing the complex relationships between various organisms and their feeding interactions. Unlike a linear food chain, a food web accounts for the multiple sources of energy and the interactions among different species.
What does the law of thermodynamics state regarding energy in an ecosystem?
The law of thermodynamics states that energy cannot be created or destroyed; it can only be transformed from one form to another. This principle governs the storage, transfer, and expenditure of energy within an ecosystem.
Why is there a decrease in useful energy as it transfers through trophic levels?
With each transfer of energy from one trophic level to the next, there is a loss of energy due to metabolic processes and heat production. As energy is passed along the food chain, not all of it is efficiently captured and converted, resulting in a decrease in useful energy at higher trophic levels.
What is the concept of ecological pyramids and who developed it?
Ecological pyramids are representations of the number of individuals, biomass, or energy at different trophic levels in a food chain. Charles Elton, an English ecologist, developed the concept of ecological pyramids.
Explain the Pyramid of Numbers.
The Pyramid of Numbers is a graphical representation of the number of individuals per unit area at various trophic levels in a food chain. It shows that producers are most numerous, followed by primary consumers, secondary consumers, and so on.
What does the Pyramid of Biomass represent?
The Pyramid of Biomass is a graphical representation of the amount of biomass (organic matter) present per unit area at different trophic levels. In terrestrial ecosystems, the highest biomass is found in producers, and there is a decrease in biomass as you move up the trophic levels.
What are biogeochemical cycles, and why are they important?
Biogeochemical cycles are cyclic pathways through which materials, such as bioelements and inorganic compounds, move from the environment to organisms and back to the environment. These cycles are important for maintaining the availability of essential nutrients and compounds for living organisms.
Explain the Carbon Cycle.
The Carbon Cycle is the cycle through which carbon atoms move between the atmosphere, living organisms, and the Earth’s crust. Carbon is taken in by producers through photosynthesis, incorporated into organic compounds, and passed through food chains. Carbon dioxide is released back into the atmosphere through respiration, decomposition, and the burning of fossil fuels. Human activities have disrupted the balance of the carbon cycle, leading to increased carbon dioxide levels and global warming.
What is the role of nitrogen in living organisms?
Nitrogen is an important component of biomolecules like proteins and nucleic acids.
Where is the primary reservoir of free gaseous nitrogen?
The atmosphere serves as the reservoir of free gaseous nitrogen.
How do living organisms obtain nitrogen from the atmosphere?
Living organisms, except for nitrogen-fixing bacteria, cannot directly take up gaseous nitrogen from the atmosphere.
What is nitrogen fixation, and how does it occur naturally?
Nitrogen fixation is the conversion of atmospheric nitrogen gas into nitrates. It occurs through processes like thunderstorms and lightning, leading to the formation of nitrous and nitric acids, which then combine with other salts to produce nitrates.
Explain the biological nitrogen fixation process.
Certain bacteria, including symbiotic and free-living varieties, have the ability to transform gaseous nitrogen into nitrates. This process is known as biological nitrogen fixation.
How is nitrogen fixation carried out industrially?
In industrial nitrogen fixation, atmospheric nitrogen is combined with hydrogen under high pressure and temperature to produce ammonia, which can be further converted into ammonium nitrate.
What is the role of ammonifying bacteria in the nitrogen cycle?
Ammonifying bacteria break down the proteins of dead organisms and nitrogenous wastes into ammonia through a process called ammonification.
Describe the process of nitrification and the types of bacteria involved.
Nitrification involves the conversion of ammonia into nitrites and then nitrates. This process is carried out by nitrifying bacteria, with Nitrosomonas converting ammonia to nitrites and Nitrobacter further converting nitrites to nitrates.
What is assimilation in the context of the nitrogen cycle?
Assimilation refers to the uptake of nitrates by plants to incorporate nitrogen into their tissues for growth.
How can excessive denitrification impact soil fertility?
Excessive denitrification can reduce soil fertility. It can be triggered by factors like waterlogging, lack of aeration, and the accumulation of organic matter in the soil.
What are intraspecific interactions and interspecific interactions?
Intraspecific interactions occur between members of the same species, while interspecific interactions occur between members of different species.
Why is intraspecific competition usually stronger than interspecific competition?
Intraspecific competition is stronger because individuals of the same species have similar resource requirements and niches, leading to more direct competition for resources.
What is predation in an ecosystem?
Predation is an interaction where one organism (predator) hunts, kills, and consumes another organism (prey) of a different species.
Give an example of a predator-prey relationship in predation.
An example of a predator-prey relationship is a frog preying upon a mosquito, or a fox preying upon a rabbit.
How does predation help maintain ecological balance?
Predation keeps prey populations in check, preventing them from becoming too large and affecting the overall balance of the ecosystem.
What are the three types of symbiosis?
The three types of symbiosis are parasitism, mutualism, and commensalism.
Describe parasitism in symbiotic interactions.
Parasitism involves one partner (parasite) deriving food and shelter from another larger partner (host), often harming the host in the process.
What is the difference between ectoparasites and endoparasites?
Ectoparasites live on the surface of the host’s body, while endoparasites live inside the host’s body.
Give an example of mutualism in symbiotic interactions.
An example of mutualism is the relationship between termites and the protozoa living in their intestines. The protozoa help digest cellulose in wood, benefiting both organisms.
Explain commensalism in symbiotic interactions with an example.
Commensalism involves one partner benefiting while the other remains unaffected. For instance, epiphytic plants growing on larger trees absorb nutrients from the air without harming the trees.
Describe the symbiotic interaction between honeyguide birds and badgers.
The honeyguide bird helps the badger locate honeycombs, and the badger opens the honeycombs to share the food. This is an example of mutualism where both species benefit.
What maintains the balance in ecosystems by recycling natural resources?
Biogeochemical cycles maintain the balance in ecosystems by recycling natural resources.
How have humans upset the delicate balance in ecosystems?
Humans have upset the delicate balance in ecosystems by modifying the environment, such as cutting down trees.
What is global warming?
Global warming refers to the increase in Earth’s temperature caused by the addition of greenhouse gases to the atmosphere, which trap heat and prevent solar radiation from reflecting back into space.
How does global warming contribute to sea level rise?
Global warming leads to the melting of polar ice-caps and glaciers, causing sea water to expand and sea levels to rise. This can lead to floods and impact coastal countries.
What is the Intergovernmental Panel on Climate Change (IPCC)?
The IPCC is an organization established by the United Nations to provide scientific advice on issues related to greenhouse gases and climate change to world leaders.
What is the greenhouse effect?
The greenhouse effect is a phenomenon where certain gases, known as greenhouse gases, trap heat in the atmosphere, similar to how a greenhouse traps heat. This leads to an increase in Earth’s temperature.
What causes acid rain?
Acid rain is caused by rainwater interacting with chemicals like oxides of sulfur and nitrogen in polluted air. These chemicals form sulfuric acid and nitric acid, which make rain acidic when they condense into liquid form.
What are the effects of acid rain on aquatic ecosystems?
Acid rain destroys nutrients in water bodies, lowers water pH, harms aquatic animals, washes nutrients out of soil, damages trees and plants, corrodes metals, and weakens building materials.
What is deforestation?
Deforestation refers to the clearing of forests due to natural causes or human activities, such as agriculture, mining, and logging.
How does overpopulation impact the environment?
Overpopulation leads to increased resource consumption, strain on infrastructure, and potential ecological imbalances.
What is urbanization?
Urbanization is the process of population growth and the expansion of cities, often resulting in challenges related to infrastructure, services, and quality of life.
How can urbanization be managed?
Urbanization can be managed through planned development, creation of green spaces, efficient transportation, and providing essential services to urban populations.
What is pollution?
Pollution is defined as any undesirable change in the physical, chemical, or biological characteristics of air, water, and land that may harmfully affect living organisms and natural resources.
How is air pollution defined, and what are its sources?
Air pollution is defined as the change in the composition of air by the addition of harmful substances. Sources of air pollution are related to human activities and include industrial and automobile gases, particulate matter, carbon monoxide, carbon dioxide, nitrogen oxides, hydrocarbons, and more.
What is smog, and how is it formed?
Smog is a mixture of gases formed when hydrocarbons and nitrogen oxides combine in the presence of sunlight. It appears as a yellowish-brown haze, especially during winter, and can cause respiratory disorders and allergies due to its polluting gases.
What are acid rains, and how are they produced?
Acid rains are formed when air pollutants like sulfur dioxide and nitrogen oxides react with water in the atmosphere, producing acidic compounds that fall to the ground as rainwater.
What are the effects of UV rays on the ozone layer?
Air pollutants like chlorofluorocarbons (CFCs) destroy the ozone molecules in the upper layer of the atmosphere, leading to the formation of ozone holes. These holes permit harmful UV rays to reach the Earth’s surface, causing increased temperatures and skin cancers.
How can air pollution be controlled?
Air pollution can be controlled through public awareness, afforestation, modification of industrial effluents, use of environment-friendly fuels, and other measures like solar cookers and bio gas production.
Define water pollution and its sources.
Water pollution is the addition of harmful substances that change the composition of water. Sources include sewage, industrial wastes, fertilizers, pesticides, oil leakage, and heavy metals.
How does eutrophication occur, and what are its effects?
Eutrophication is the enrichment of water with inorganic nutrients, leading to algal blooms and oxygen depletion. This reduces light penetration and harms aquatic life.
What are the major effects of water pollution?
Effects of water pollution include food chain contamination, epidemics due to organic pollutants, and adverse health effects caused by heavy metals and chemicals.
How can land pollution be controlled?
Land pollution can be controlled through proper waste disposal, recycling non-biodegradable materials, using organic pesticides, and reforestation.
Question: Explain what do you mean by the pyramids of number and biomass.
Answer: Pyramids of Number and Biomass
Ecological pyramids are graphical representations of the relationships between different trophic levels in an ecosystem. The pyramid of numbers depicts the number of individuals at each trophic level. It typically shows that the number of producers is the highest, followed by a decreasing number of consumers at higher trophic levels. The pyramid of biomass, on the other hand, represents the total mass of organisms at each trophic level. It demonstrates that the biomass (amount of living material) decreases as you move up the food chain due to energy loss.
Question: Write a note on Carbon cycle.
Answer: Carbon Cycle
The carbon cycle is the process through which carbon compounds are exchanged among the atmosphere, oceans, soil, and living organisms. It involves processes like photosynthesis (plants take in carbon dioxide and convert it into organic compounds), respiration (organisms release carbon dioxide back into the atmosphere), decomposition (breaking down of organic matter by decomposers), and combustion (burning of fossil fuels releasing carbon dioxide into the atmosphere). Human activities, such as burning fossil fuels and deforestation, have disrupted the carbon cycle, leading to an increase in atmospheric carbon dioxide and contributing to global warming.
Question: What are the different stages of Nitrogen cycle?
Answer: Stages of Nitrogen Cycle
The nitrogen cycle involves several stages:
a. Nitrogen Fixation: Conversion of atmospheric nitrogen gas into ammonia or other nitrogen compounds, either by lightning, nitrogen-fixing bacteria, or industrial processes.
b. Nitrification: Conversion of ammonia into nitrites and then into nitrates by nitrifying bacteria.
c. Assimilation: Incorporation of nitrates and ammonia into organic molecules by plants, which are then consumed by animals.
d. Ammonification: Decomposition of organic matter by bacteria and fungi, releasing ammonia back into the soil.
e. Denitrification: Conversion of nitrates in the soil back into nitrogen gas by denitrifying bacteria, completing the cycle.
Question: Write notes on competition, predation and symbiosis.
Answer: Competition, Predation, and Symbiosis
These are three ecological interactions:
Competition: When different organisms compete for limited resources like food, water, and shelter. It can be intraspecific (within the same species) or interspecific (between different species).
Predation: The interaction where one organism (predator) hunts and feeds on another organism (prey) for sustenance.
Symbiosis: A close and prolonged interaction between two different species. It includes mutualism (both species benefit), commensalism (one benefits, the other is neither helped nor harmed), and parasitism (one benefits while the other is harmed).
Question: Explain how human activities have contributed to the loss of balance in nature.
Answer: Human Activities and Loss of Balance in Nature
Human activities, such as deforestation, pollution, overfishing, and industrialization, have disrupted natural ecosystems. These activities have led to habitat destruction, species extinction, climate change, air and water pollution, and alteration of nutrient cycles. The loss of biodiversity, ecosystem degradation, and imbalance in natural processes threaten the stability and resilience of ecosystems.
Question: Write note on the causes and effects of the air and water pollutions.
Answer: Air and Water Pollution
Air pollution refers to the introduction of harmful substances into the air, such as pollutants from industrial emissions, vehicle exhaust, and burning of fossil fuels. This leads to smog, acid rain, and respiratory problems. Water pollution is the contamination of water bodies with pollutants like industrial waste, sewage, and agricultural runoff. This can harm aquatic life, contaminate drinking water sources, and lead to the degradation of ecosystems.
Question: What are the different levels of ecological organization?
Answer: The different levels of ecological organization are organism, population, community, ecosystem, biome, and biosphere.
Question: Define ecosystem and its components.
Answer: An ecosystem is a self-sustaining unit formed by the interactions between living organisms (biotic components) and their physical environment (abiotic components). Biotic components include producers (plants), consumers (animals), and decomposers (bacteria and fungi). Abiotic components encompass non-living factors such as light, air, water, soil, and minerals.
Question: How the flow of energy is different from that of materials?
Answer: The flow of energy in an ecosystem is unidirectional, moving from the sun to producers (plants) and through various trophic levels of consumers, ultimately dissipating as heat. Energy is not recycled within the ecosystem and is constantly received from the sun.
On the other hand, the flow of materials, such as nutrients and elements like carbon, nitrogen, and phosphorus, is cyclical. These materials are continuously recycled through processes like decomposition, assimilation, and release, allowing them to be used by different organisms at various levels in the ecosystem.
Question:. Define food chain and food web.
Answer: A food chain is a linear sequence that illustrates the transfer of energy and nutrients from one organism to another as they consume and are consumed. It typically consists of a series of trophic levels, starting with producers (plants) and progressing through primary consumers (herbivores) and secondary consumers (carnivores), and so on.
A food web, on the other hand, is a more complex representation of the feeding relationships in an ecosystem. It involves interconnected food chains, showing how various organisms are linked through multiple feeding interactions. Food webs provide a more accurate depiction of the diverse feeding relationships and interactions within an ecosystem.
Question: What do you mean by the concept of 3Rs with reference to the conservation of natural resources?
Answer: The concept of 3Rs refers to “Reduce, Reuse, and Recycle,” which are strategies aimed at promoting the responsible use and conservation of natural resources and minimizing waste production.
Reduce: This involves using resources more efficiently and consuming less. It includes practices like conserving energy and water, using public transportation, and minimizing excessive consumption.
Reuse: Instead of discarding items after single use, reusing them for different purposes extends their lifespan and reduces the need for new resources. For example, using reusable water bottles and shopping bags.
Recycle: Recycling involves collecting, processing, and reusing materials from discarded products to create new products. This reduces the demand for raw materials, conserving energy and minimizing waste.