Biology: Topic-wise Test- 8 - NEET MCQ

Kyoto Protocol
The Kyoto Protocol is an international treaty that was adopted in 1997 and came into force in 2005. It is an agreement under the United Nations Framework Convention on Climate Change (UNFCCC) and aims to address the issue of climate change through the reduction of greenhouse gas emissions. The protocol has several key features and objectives that are related to climate change.
1. Greenhouse gas emissions reduction
- The primary goal of the Kyoto Protocol is to reduce greenhouse gas emissions in order to mitigate climate change.
- It sets binding targets for developed countries to reduce their emissions by a certain percentage below their 1990 levels.
2. Commitments and mechanisms
- The protocol includes different mechanisms to help countries meet their emission reduction targets, such as emissions trading, clean development mechanism, and joint implementation.
- These mechanisms provide flexibility and financial incentives for countries to invest in emission reduction projects.
3. Differentiated responsibilities
- The Kyoto Protocol recognizes the principle of "common but differentiated responsibilities" between developed and developing countries.
- Developed countries have legally binding targets, while developing countries are encouraged to take voluntary actions to address climate change.
4. Adaptation and support
- The protocol emphasizes the need for adaptation to the impacts of climate change and provides support to developing countries in this regard.
- It establishes a financial mechanism to assist developing countries in implementing climate change mitigation and adaptation measures.
5. Compliance and enforcement
- The Kyoto Protocol includes provisions for monitoring, reporting, and verification of greenhouse gas emissions.
- It also establishes a compliance mechanism to address non-compliance by countries with their emission reduction commitments.
In conclusion, the Kyoto Protocol is primarily related to climate change and aims to reduce greenhouse gas emissions to mitigate global warming. It sets binding targets, establishes mechanisms, and promotes differentiated responsibilities and support for developing countries in addressing climate change.

The First Earth Summit held at Rio de Janeiro in 1992
The first Earth Summit, also known as the United Nations Conference on Environment and Development (UNCED), took place in Rio de Janeiro, Brazil in 1992. It was a significant event that brought together leaders from around the world to address pressing environmental and sustainable development issues. The summit resulted in several outcomes and initiatives, including:
A: Red Data Book Publication and IUCN, UNEP
- The publication of the Red Data Book, which is a comprehensive list of endangered species and their conservation status.
- Collaboration between the International Union for Conservation of Nature (IUCN) and the United Nations Environment Programme (UNEP) to protect and preserve biodiversity.
B: Agenda 21
- The adoption of Agenda 21, a comprehensive action plan for achieving sustainable development globally. It covers various aspects such as social, economic, and environmental dimensions of sustainability.
- Agenda 21 provides guidelines and recommendations for governments, organizations, and communities to promote sustainable practices and address challenges related to poverty, pollution, and resource depletion.
C: Convention on Biodiversity
- The establishment of the Convention on Biological Diversity (CBD), which aims to conserve biodiversity, promote the sustainable use of its components, and ensure the fair and equitable sharing of benefits derived from genetic resources.
- The CBD is an international treaty that has been ratified by numerous countries and serves as a framework for biodiversity conservation and sustainable development efforts worldwide.
D: Both 2 and 3
- The first Earth Summit resulted in both the publication of the Red Data Book and the collaboration between IUCN and UNEP, as well as the adoption of Agenda 21 and the establishment of the Convention on Biodiversity.
Therefore, the correct answer is D, as both options 2 and 3 are outcomes of the first Earth Summit held in Rio de Janeiro in 1992.

India's Climatic Zones
India is a vast country with diverse geographical features, and it is home to several climatic zones. The climatic zones in India are classified based on temperature, rainfall, and vegetation patterns. The answer to the given question is option C, which represents a temperature range of 40°C to 60°C.
Here is a detailed explanation of India's climatic zones:
1. Tropical Rainforest Climate Zone
- Found in the Western Ghats, northeastern India, and the Andaman and Nicobar Islands.
- Characterized by high rainfall throughout the year, with temperatures usually above 18°C.
- Dense vegetation, including evergreen forests, is a distinctive feature of this zone.
2. Tropical Monsoon Climate Zone
- Covers a large part of India, including the coastal regions and the Indo-Gangetic plains.
- Experiences distinct seasons, with a hot and wet summer (monsoon season) and a relatively cooler and drier winter.
- The temperature ranges from 20°C to 40°C, and the annual rainfall is high.
3. Subtropical Climate Zone
- Found in the northern parts of India, including the Himalayan region.
- Summers are hot with temperatures ranging between 30°C to 40°C, while winters can be cold with temperatures dropping below freezing point.
- The rainfall is moderate, and the vegetation varies from deciduous forests to alpine meadows.
4. Desert Climate Zone
- Primarily located in the northwestern part of India, including the Thar Desert (Rajasthan).
- Characterized by extremely high temperatures, ranging from 40°C to 50°C during summers, and a significant temperature drop during winter nights.
- Annual rainfall is minimal, and the vegetation is sparse, mainly consisting of thorny shrubs and cacti.
5. Highland Climate Zone
- Encompasses the regions of the Western Ghats and the northeastern states.
- The temperature varies with altitude, and the rainfall is heavy due to orographic factors.
- The vegetation includes evergreen forests, grasslands, and bamboo thickets.
In conclusion, India experiences a wide range of climatic zones, ranging from tropical rainforests to deserts and highlands. It is important to note that these zones may overlap in certain regions, leading to unique microclimates within the country.

The vertical temperature gradient over Earth's surface is known as the lapse rate.
The lapse rate refers to the change in temperature with respect to altitude or height in the Earth's atmosphere. It is an important concept in meteorology and climatology and plays a significant role in determining weather patterns and atmospheric stability. Here is a detailed explanation of the vertical temperature gradient:
Definition:
The lapse rate is defined as the rate at which the temperature decreases or increases with an increase in altitude.
Factors influencing the lapse rate:
1. Solar radiation: The Sun's energy is the primary driver of temperature variations on Earth's surface. Differential heating due to the angle and intensity of solar radiation leads to variations in temperature with altitude.
2. Atmospheric composition: The composition of the atmosphere, including the presence of greenhouse gases, affects the absorption and re-radiation of heat. This can impact the vertical temperature profile.
3. Adiabatic processes: As air masses rise or descend, they undergo adiabatic processes that cause changes in temperature. These processes include adiabatic cooling and adiabatic heating, which contribute to the overall lapse rate.
Types of lapse rates:
1. Environmental lapse rate (ELR): This refers to the actual temperature change observed in the atmosphere. The ELR can vary depending on local weather conditions, time of day, and geographical location.
2. Dry adiabatic lapse rate (DALR): This is the rate at which dry air cools or warms as it rises or descends in the atmosphere without any condensation or evaporation occurring. The DALR is approximately 9.8°C per kilometer.
3. Moist adiabatic lapse rate (MALR): This is the rate at which moist air cools or warms as it rises or descends in the atmosphere and undergoes condensation or evaporation. The MALR is generally lower than the DALR and varies depending on the amount of water vapor present.
Importance:
- The lapse rate is crucial in determining the stability of the atmosphere. A steep lapse rate indicates greater instability and the potential for convective activity, such as thunderstorms.
- The vertical temperature gradient affects the formation and dissipation of clouds, as well as the development of precipitation.
- Understanding the lapse rate is essential for aviation as it helps predict turbulence and other atmospheric conditions that can impact aircraft operations.
In conclusion, the vertical temperature gradient over Earth's surface is known as the lapse rate. It is influenced by various factors and plays a significant role in weather patterns, atmospheric stability, and aviation operations.

Blue Baby Syndrome caused due to Nitrate:
Nitrate is a common chemical found in fertilizers, sewage, and industrial waste. When consumed in high levels, it can lead to a condition known as Blue Baby Syndrome or methemoglobinemia. This condition occurs when nitrate is converted into nitrite in the body, which interferes with the normal functioning of red blood cells, reducing their ability to carry oxygen. This, in turn, leads to a bluish discoloration of the skin and mucous membranes, hence the name Blue Baby Syndrome.
How does nitrate cause Blue Baby Syndrome?
- Nitrate is converted into nitrite in the body, which binds to hemoglobin in red blood cells, forming methemoglobin.
- Methemoglobin cannot carry oxygen as efficiently as normal hemoglobin, leading to oxygen deprivation in the body.
- The lack of oxygen causes the skin and mucous membranes to turn bluish or cyanotic.
Sources of nitrate:
- Fertilizers: Nitrate is commonly used in agricultural fertilizers, and excessive use can lead to the contamination of groundwater and drinking water sources.
- Sewage and wastewater: Nitrate can be present in sewage and wastewater, especially in areas with inadequate treatment systems.
- Industrial waste: Certain industries, such as mining and manufacturing, may release nitrate-containing waste into the environment, contaminating water sources.
Preventing Blue Baby Syndrome:
- Regular testing of drinking water for nitrate levels.
- Using alternative sources of water if nitrate levels are high.
- Treating water sources to remove nitrate contamination.
- Properly managing and disposing of sewage and wastewater.
- Implementing regulations and guidelines to control industrial waste discharge.
It is important to note that while nitrate is a common cause of Blue Baby Syndrome, other substances such as arsenic, cadmium, and methyl mercury can also contribute to this condition in certain cases. Therefore, it is crucial to address and mitigate the sources of these harmful substances to prevent Blue Baby Syndrome and ensure the safety of drinking water.

NEERI is located in Nagpur

• NEERI (National Environmental Engineering Research Institute) is located in Nagpur.


• Nagpur is a city in the state of Maharashtra, India.


• It is the headquarters of NEERI and is known for its research and development work in the field of environmental engineering.


• NEERI is a premier research institute under the Council of Scientific and Industrial Research (CSIR), which is a government organization in India.


• The institute is involved in various research projects related to environmental issues, pollution control, waste management, and sustainable development.


• NEERI collaborates with national and international organizations to address environmental challenges and provide solutions.


• The institute has state-of-the-art laboratories, research facilities, and a team of highly qualified scientists and researchers.


• NEERI conducts research, training programs, and provides consultancy services to industries, government agencies, and other stakeholders.


• The location of NEERI in Nagpur is advantageous as it allows easy access to different parts of the country for field studies and collaborations.


• NEERI's presence in Nagpur contributes to the city's reputation as a center for scientific research and innovation.

Explanation:
The correct answer to the question is B: Taungya System.
The Taungya System is a method of agroforestry where rows of planted trees are grown along with crops. Here is a detailed explanation of the Taungya System:
Definition of the Taungya System:
- The Taungya System is a traditional agroforestry practice in which annual crops are grown in the early years of establishing a forest plantation.
- It involves planting rows of trees along with agricultural crops in the same field.
Key features of the Taungya System:
- Coexistence of trees and crops: In the Taungya System, rows of trees are planted in the same field where agricultural crops are grown.
- Temporary nature of crops: The crops grown in the system are usually annual or short-term crops that can be harvested before the trees mature.
- Tree establishment: The primary purpose of the Taungya System is to establish a forest plantation, and the trees are the main focus of the system.
- Crop benefits: The crops provide temporary economic benefits to the farmers while the trees are growing.
- Land utilization: The system optimizes land use by utilizing the space between tree rows for agricultural activities.
Advantages of the Taungya System:
- Soil conservation: The presence of trees helps in preventing soil erosion and improving soil fertility.
- Diversification: The system allows for diversification of income sources as farmers can earn from both crops and timber.
- Carbon sequestration: The trees planted in the system contribute to carbon sequestration, helping in mitigating climate change.
- Economic benefits: The crops provide short-term economic benefits, while the trees can generate long-term income through timber production.
- Sustainable land use: The Taungya System promotes sustainable land use by combining forestry and agriculture in a mutually beneficial way.
In conclusion, the practice of growing crops along with rows of planted trees is known as the Taungya System. This system allows for the establishment of forest plantations while providing temporary economic benefits through agricultural crops. It is a sustainable approach that promotes soil conservation, diversification of income sources, and carbon sequestration.

Rainwater Harvesting and its relation to conservation and management of rainwater
Rainwater harvesting is a common practice adopted by various institutions, including the Municipal Corporation of Delhi (MCD), in India. It is a technique that involves collecting, storing, and utilizing rainwater for various purposes. The main objective of rainwater harvesting is the conservation and management of rainwater resources.
Importance of rainwater harvesting:
1. Water scarcity: Many parts of India face water scarcity issues, especially during dry seasons. Rainwater harvesting helps in augmenting water supply during such periods.
2. Groundwater recharge: By collecting rainwater and storing it in underground tanks or recharge pits, rainwater harvesting helps replenish groundwater levels, which is crucial for sustaining water resources.
3. Reducing runoff and flooding: Harvesting rainwater reduces the volume of runoff, which in turn helps prevent flooding and soil erosion.
4. Sustainable water management: Rainwater harvesting promotes the efficient use of water resources, reducing dependence on external sources and ensuring water security.
5. Cost-effective: Implementing rainwater harvesting systems can help reduce water bills and provide a cost-effective solution for water supply.
Process and techniques of rainwater harvesting:
1. Rooftop collection: Rainwater is collected from rooftops using gutters and directed towards storage tanks.
2. Surface runoff collection: Rainwater is collected from paved surfaces, such as roads and parking lots, using channels and drains, and stored in tanks or ponds.
3. Recharge pits: Rainwater is allowed to percolate into the ground through recharge pits or wells, replenishing groundwater sources.
4. Infiltration trenches: Trenches filled with gravel or other permeable materials are constructed to allow rainwater to infiltrate into the ground, recharging aquifers.
5. Check dams and ponds: Rainwater is stored in small check dams or ponds, which can be later used for irrigation or other purposes.
Benefits of rainwater harvesting:
1. Conservation of water resources: Rainwater harvesting helps conserve precious water resources by utilizing rainwater efficiently.
2. Reduction in water bills: By relying on harvested rainwater, individuals and institutions can reduce their dependence on expensive external water sources.
3. Groundwater recharge: Rainwater harvesting contributes to recharging groundwater sources, ensuring their sustainability.
4. Mitigation of flooding and soil erosion: By reducing runoff, rainwater harvesting helps prevent flooding and soil erosion.
5. Self-sufficiency: Rainwater harvesting systems provide a self-sufficient water supply, especially during dry periods or in areas with limited water resources.
In conclusion, rainwater harvesting is a vital practice for the conservation and management of rainwater resources in India. It helps address water scarcity issues, promotes sustainability, and reduces dependence on external water sources.

Afforestation:
Afforestation is the extensive planting of trees in order to increase forest cover. It is an important measure taken to combat deforestation and restore ecological balance. Let's explore the concept of afforestation in detail:
Benefits of Afforestation:
1. Environmental Benefits:
- Increases forest cover, which helps in mitigating climate change by absorbing carbon dioxide and releasing oxygen.
- Improves air quality by filtering pollutants and dust particles.
- Enhances biodiversity by providing habitat for various plant and animal species.
- Reduces soil erosion and prevents landslides by stabilizing the soil with tree roots.
2. Socio-economic Benefits:
- Provides livelihood opportunities through forestry-related activities such as timber production, non-timber forest products, and ecotourism.
- Enhances water resources by promoting water infiltration and maintaining water tables.
- Offers recreational and aesthetic values, contributing to the well-being of communities.
Methods of Afforestation:
1. Direct Seeding:
- Seeds of desired tree species are directly sown in the target area, allowing natural germination and growth.
- Suitable for areas with favorable soil conditions and sufficient rainfall.
2. Nursery Planting:
- Tree saplings are grown in nurseries under controlled conditions and then transplanted to the target area.
- Provides better control over the growth and survival of trees.
- Suitable for areas with challenging environmental conditions.
3. Agroforestry:
- Involves planting trees alongside agricultural crops or livestock farming.
- Provides multiple benefits such as improved soil fertility, shade for crops or livestock, and diversification of income sources for farmers.
4. Social Forestry:
- Involves the participation of local communities in afforestation activities.
- Aims to meet the needs of local communities while promoting sustainable forest management.
- Enhances community ownership and engagement in forest conservation.
Conclusion:
Afforestation plays a crucial role in increasing forest cover, protecting the environment, and providing numerous socio-economic benefits. It is an effective strategy to combat deforestation and promote sustainable development. By understanding the importance and methods of afforestation, we can actively contribute to the conservation and restoration of our forests.

The Bio-diversity bill passed in parliament in December 2002:
Introduction:
The Bio-diversity bill is an important legislation that aims to protect and conserve the rich biodiversity of a country. In this case, we are discussing the passage of the Bio-diversity bill in the Indian parliament.
Explanation:
The correct answer to the question is option B, December 2002. Here is a detailed explanation:
1. Background:
- The Bio-diversity bill was introduced to address the conservation and sustainable use of biological resources in India.
- It aimed to provide a legal framework for the protection and management of biodiversity in the country.
2. Timeline:
- May 2004: This option is incorrect as it comes after December 2002, which is the correct answer.
- 11 December 2000: This option is incorrect as it is before December 2002, which is the correct answer.
- 6 January 2000: This option is incorrect as it is also before December 2002, which is the correct answer.
3. Passage of the Bio-diversity bill:
- The Bio-diversity bill was passed in the Indian parliament in December 2002.
- This means that it received the necessary approvals and became a law during this period.
4. Significance:
- The passage of the Bio-diversity bill marked a significant step towards the conservation and sustainable use of India's rich biodiversity.
- It provided a legal framework for the protection of biological resources, their sustainable utilization, and the fair sharing of benefits arising from their use.
In conclusion, the Bio-diversity bill was passed in the Indian parliament in December 2002. This legislation plays a crucial role in the conservation and sustainable use of India's biodiversity.

Answer: D
Explanation:
Under symbiosis, the different types of interactions between organisms can be categorized into mutualism, protocooperation, and commensalism. Therefore, the statement that mutualism, protocooperation, and commensalism cannot be included under symbiosis is incorrect.
Details:
- Mutualism: It is a type of symbiotic relationship where both organisms benefit from each other's presence. Lichen, which is an association of fungus and alga, is a classic example of mutualism. The fungus provides a suitable environment and protection for the alga, while the alga provides nutrients through photosynthesis for the fungus.
- Protocooperation: It is a type of symbiotic relationship where both organisms benefit from each other's presence but can survive independently as well. The association between Sea Anemone and Hermit Crab is an example of protocooperation. The sea anemone provides protection to the hermit crab by stinging predators, and in return, the hermit crab provides the sea anemone with mobility and access to food.
- Commensalism: It is a type of symbiotic relationship where one organism benefits while the other is neither harmed nor benefited. Epiphytes, which use other plants for support without obtaining water or food from them, exhibit commensalism.
Therefore, the correct option is D, as all the other statements are accurate.

Two species cannot live in the same niche due to
A: Allen's Law
- Allen's Law states that animals in colder climates tend to have smaller appendages.
- This law does not directly relate to the coexistence of species in the same niche.
B: Gause Hypothesis
- The Gause Hypothesis, also known as the competitive exclusion principle, states that two species competing for the same resources cannot coexist indefinitely.
- According to this hypothesis, one species will eventually outcompete and exclude the other from the niche.
- The principle is based on the idea that resources within a niche are limited and cannot support the long-term survival of two competing species.
C: Doll's Rule
- Doll's Rule states that larger species of a taxonomic group tend to occupy a broader range of habitats.
- This rule does not directly address the coexistence of species in the same niche.
D: Weismann's Theory
- Weismann's Theory, also known as the germ-plasm theory, pertains to the continuity of hereditary material in reproductive cells.
- It does not specifically relate to the coexistence of species in the same niche.
Answer: B. Gause Hypothesis
- The Gause Hypothesis is the most relevant explanation for why two species cannot live in the same niche.
- The principle suggests that competition for limited resources leads to the exclusion of one species by another, ultimately resulting in the coexistence of only one species in a particular niche.

Association between entomophilious flowers and pollinating agent

• Definition of entomophilous flowers: Entomophilous flowers are flowers that are adapted for pollination by insects.


• Definition of pollinating agent: A pollinating agent is the organism that transfers pollen from the male reproductive organ of a flower to the female reproductive organ, resulting in fertilization.


• Explanation of the association between entomophilous flowers and pollinating agent:

1. Commensalism: Commensalism is a type of symbiotic relationship in which one organism benefits without affecting the other. In the case of entomophilous flowers and pollinating agents, this association does not fall under commensalism as both the flowers and the pollinating agents benefit from the interaction.


2. Coevolution: Coevolution refers to the mutual evolutionary influence between two or more species. In the case of entomophilous flowers and pollinating agents, there is a strong association of coevolution. The flowers have evolved specific characteristics, such as bright colors, attractive scents, and nectar production, to attract the pollinating agents. The pollinating agents, in turn, have evolved traits that enable them to efficiently gather pollen and nectar from the flowers.


3. Mutualism: Mutualism is a type of symbiotic relationship in which both organisms benefit from the interaction. The association between entomophilous flowers and pollinating agents can be considered mutualistic. The flowers provide the pollinating agents with nectar as a food source, while the pollinating agents facilitate the transfer of pollen, leading to fertilization and the production of seeds.


4. Cooperation: Cooperation refers to the act of working together for mutual benefit. The association between entomophilous flowers and pollinating agents involves cooperation, as both parties work together to accomplish the mutual goal of pollination and reproduction.

Therefore, the correct answer is Coevolution (B). The association between entomophilous flowers and pollinating agents is an example of coevolution, as both species have evolved together to optimize the process of pollination and reproduction.

Ecofriendly method is:
There are several eco-friendly methods that can be implemented to promote sustainability and protect the environment. One such method is energy plantation. Energy plantation involves the cultivation of specific plant species that are grown for the purpose of producing biomass for energy production. Here are some key points about energy plantation as an eco-friendly method:
1. Definition: Energy plantation refers to the cultivation of fast-growing plants, such as bamboo or certain types of grasses, with the primary aim of utilizing them as a renewable source of energy.
2. Biomass production: These plants are specifically chosen for their high biomass yields, meaning they can produce a large amount of organic matter that can be used as fuel for energy generation.
3. Renewable energy: The biomass produced from energy plantation can be utilized to generate renewable energy in the form of biofuels, biogas, or even electricity through processes like combustion, anaerobic digestion, or bioconversion.
4. Reduced carbon emissions: By using biomass from energy plantation as an alternative to fossil fuels, carbon emissions can be significantly reduced, as the combustion of biomass releases only the same amount of carbon dioxide that the plants absorbed during their growth.
5. Environmental benefits: Energy plantation helps in preserving natural resources and biodiversity by reducing the dependence on non-renewable energy sources. It also contributes to the reduction of greenhouse gas emissions and mitigates climate change.
6. Land utilization: Energy plantation can be established on degraded or marginal lands that are not suitable for traditional agriculture, thereby minimizing competition for land resources.
7. Economic opportunities: Energy plantation can create employment opportunities in rural areas, as it requires labor-intensive activities such as planting, cultivation, and harvesting.
8. Sustainable development: By promoting energy plantation as an eco-friendly method, we can work towards achieving sustainable development goals by ensuring energy security, reducing pollution, and promoting rural development.
In conclusion, energy plantation is an eco-friendly method that utilizes fast-growing plants to produce biomass for renewable energy production. It offers several environmental and economic benefits while reducing carbon emissions and promoting sustainable development.

Rate of replacement of species along a gradient of habitats/communities is called:
The correct answer is B. Beta diversity.
Explanation:
Beta diversity refers to the rate of species replacement or turnover along a gradient of habitats or communities. It measures the change in species composition or diversity between different sites or habitats. Beta diversity is important because it provides insights into the variation in species distribution and turnover across different environments.
Some key points about beta diversity include:
1. Definition: Beta diversity is a measure of the turnover or replacement of species along a spatial or environmental gradient.
2. Variation in species composition: Beta diversity quantifies the differences in species composition between different sites or habitats.
3. Importance: Beta diversity helps us understand the ecological processes that drive species turnover and distribution patterns.
4. Calculation: Beta diversity can be calculated using various metrics, such as the Jaccard index or the Simpson index, depending on the research question and data available.
5. Conservation implications: Understanding beta diversity can be crucial for conservation planning, as it allows us to identify areas of high species turnover and prioritize conservation efforts.
In summary, beta diversity is the rate of species replacement or turnover along a gradient of habitats or communities, and it is an important concept in ecology and conservation biology.

Clearing Water Body:
A: Chlorella
- Chlorella is a type of green algae that can be used to clear water bodies.
- It is a single-celled organism that is capable of photosynthesis.
- Chlorella can consume excess nutrients, such as nitrogen and phosphorus, found in the water.
- By absorbing these nutrients, it helps to reduce the growth of algae and other unwanted organisms in the water.
- Chlorella also produces oxygen, which can improve the overall oxygen levels in the water.
- Its rapid growth rate makes it an effective tool for water purification.
B: Eichhornia
- Eichhornia, also known as water hyacinth, is a floating aquatic plant that can be used for clearing water bodies.
- It has a high growth rate and can quickly cover the surface of the water.
- Eichhornia can absorb excess nutrients, such as nitrogen and phosphorus, through its roots.
- This helps to reduce the availability of these nutrients for algae and other unwanted organisms.
- The dense growth of Eichhornia can also provide shade, reducing the amount of sunlight reaching the water and inhibiting the growth of algae.
- However, excessive growth of Eichhornia can lead to oxygen depletion and harm aquatic life.
C: Cyanobacteria
- Cyanobacteria, also known as blue-green algae, can be used for clearing water bodies.
- Certain species of cyanobacteria are capable of fixing atmospheric nitrogen, converting it into a form that can be utilized by other organisms.
- This process helps to reduce the levels of excess nitrogen in the water, limiting the growth of algae and other unwanted organisms.
- Cyanobacteria can also produce oxygen through photosynthesis, improving the oxygen levels in the water.
- However, some species of cyanobacteria can produce harmful toxins, posing a risk to human and animal health.
D: Chlamydomonas
- Chlamydomonas is a genus of green algae that can be used for clearing water bodies.
- It is a unicellular organism that can photosynthesize and absorb excess nutrients from the water.
- Chlamydomonas can consume nitrogen and phosphorus, helping to reduce the availability of these nutrients for algae and other unwanted organisms.
- Its ability to reproduce quickly makes it an effective tool for water purification.
- However, excessive growth of Chlamydomonas can lead to oxygen depletion and harm aquatic life.
In conclusion, Chlorella, Eichhornia, Cyanobacteria, and Chlamydomonas are all organisms that can be used for clearing water bodies. Each of these organisms has specific properties and capabilities that make them effective in reducing excess nutrients and improving water quality. However, it is important to consider the potential negative impacts of these organisms, such as oxygen depletion and toxin production, before implementing them as water purification methods.

Biological magnification is the process by which the concentration of toxic substances increases as they move up the food chain. This occurs because the toxic substances are not easily broken down or eliminated from the body, and they accumulate in higher concentrations in organisms at higher trophic levels.
The specific case of biological magnification mentioned in the question is related to organochlorine insecticides. Here is a detailed explanation:
1. Organochlorine insecticides:
- Organochlorine insecticides, such as DDT (dichlorodiphenyltrichloroethane), were widely used in the past for pest control.
- These insecticides are highly persistent and do not easily break down in the environment.
- When these insecticides are sprayed on crops or used in other applications, they can enter water bodies and soil.
- Organisms in these habitats, such as fish or insects, can absorb the insecticides through their gills or other body parts.
- As these organisms are consumed by larger organisms, such as birds or mammals, the concentration of the insecticides becomes more concentrated in their bodies.
- This process continues as the larger organisms are consumed by even larger ones, resulting in a higher concentration of the insecticides at the top of the food chain.
- The accumulation of organochlorine insecticides in organisms at higher trophic levels can have harmful effects on their health and reproduction.
It is important to note that biological magnification can also occur with other toxic substances, such as heavy metals or certain organic pollutants, but in the given options, the correct answer is A: Organochlorine insecticides.

Explanation:
Greenhouse gases and greenhouse effect:
- Greenhouse gases such as carbon dioxide, methane, and water vapor trap heat in the atmosphere.
- This trapped heat is known as the greenhouse effect and is essential for maintaining a habitable temperature on Earth.
Heat radiated back from greenhouse gases:
- Greenhouse gases absorb and re-emit infrared radiation, also known as heat, back into the atmosphere.
- This heat radiated back from greenhouse gases is called greenhouse flux.
Impact of greenhouse flux:
- The greenhouse flux contributes to the overall warming of the Earth's surface and atmosphere.
- It plays a significant role in the process of global warming and climate change.
Options:
A: Additional global warming
- This option is incorrect as the greenhouse flux is already a part of the global warming process. It does not cause additional global warming.
B: Thermal inversion
- This option is correct.
- Thermal inversion refers to a weather phenomenon where a layer of warm air gets trapped above a layer of cool air close to the ground.
- The greenhouse flux can contribute to thermal inversions by trapping heat near the surface and inhibiting vertical mixing of the atmosphere.
C: Eutrophication
- Eutrophication refers to an excessive growth of algae and other aquatic plants due to an increase in nutrient levels in water bodies.
- The greenhouse flux is not directly related to eutrophication, so this option is incorrect.
D: Smog
- Smog is a type of air pollution that occurs when pollutants such as nitrogen oxides and volatile organic compounds react with sunlight.
- While the greenhouse flux can contribute to overall warming and climate change, it is not directly responsible for the formation of smog. This option is incorrect.
Conclusion:
The correct answer is B: Thermal inversion, as the greenhouse flux can contribute to the occurrence of thermal inversions by trapping heat near the surface and inhibiting vertical mixing of the atmosphere.

Minamata and itai-itai are caused by pollution of Mercury and Cadmium.
Explanation:
- Minamata disease is caused by the release of methylmercury into the environment. This pollution occurred in Minamata, Japan, in the mid-20th century due to industrial wastewater being discharged into Minamata Bay by a chemical factory. The mercury contaminated the seafood in the bay, which was then consumed by the local population, leading to severe neurological symptoms.
- Itai-itai disease, also known as "ouch-ouch disease," is caused by cadmium pollution. It occurred in the Jinzu River basin in Japan due to mining operations and industrial waste disposal. Cadmium contaminated the rice fields and water sources in the area, leading to cadmium poisoning and resulting in symptoms such as severe pain, brittle bones, and kidney failure.
- Both diseases are examples of environmental pollution and highlight the detrimental effects of heavy metals on human health.
- Mercury and cadmium are highly toxic substances that can bioaccumulate in the food chain, leading to long-term health risks for individuals exposed to polluted environments.
- Strict regulations and pollution control measures are necessary to prevent such incidents and protect public health.

Trophic Level of Man in an Ecosystem:
The trophic level of an organism refers to its position in the food chain or food web of an ecosystem. It indicates the source of energy and the type of organisms that an organism consumes and is consumed by. In the case of humans, the trophic level can be determined by examining their diet and feeding habits.
The trophic level of man in an ecosystem is:
A: Omnivore
Explanation:
- Humans are classified as omnivores because they consume both plants and animals.
- As omnivores, humans have the ability to obtain energy from a wide range of food sources, including fruits, vegetables, grains, meat, and fish.
- This versatility allows humans to occupy a higher trophic level in the food chain compared to herbivores, which primarily consume plants, and carnivores, which primarily consume other animals.
- Humans can obtain energy from both producers (plants) and consumers (animals), allowing them to have a more diverse diet and occupy a more flexible ecological niche.
- Being an omnivore gives humans the ability to adapt to different environments and food availability, which has contributed to their success as a species.
Conclusion:
In summary, the trophic level of humans in an ecosystem is that of an omnivore. This classification is based on their ability to consume both plants and animals, giving them a diverse diet and the flexibility to occupy a higher trophic level in the food chain.

Explanation:
The rate at which light energy is converted into chemical energy of organic molecules is known as the ecosystem's primary productivity. This process occurs through photosynthesis, where plants and other photosynthetic organisms use sunlight to convert carbon dioxide and water into glucose and oxygen. The energy stored in glucose is then used by organisms in the ecosystem for various purposes.
Primary productivity:
Primary productivity refers to the rate at which autotrophic organisms (such as plants) convert light energy into chemical energy through photosynthesis. It represents the total amount of energy that is available for consumption by heterotrophic organisms in the ecosystem.
Net primary productivity (NPP):
NPP is the amount of energy that is available for consumption by heterotrophs after autotrophs have utilized some of the energy for their own metabolic processes. It is calculated by subtracting the energy used by autotrophs (respiration) from the gross primary productivity.
Gross primary productivity (GPP):
GPP is the total amount of energy that is fixed by autotrophs through photosynthesis. It represents the total energy captured by autotrophs in an ecosystem.
Gross secondary productivity:
Gross secondary productivity is the amount of energy that is gained by heterotrophs through the consumption of other organisms. It is the total energy acquired by heterotrophs through feeding.
Conclusion:
The rate at which light energy is converted into chemical energy of organic molecules is represented by the ecosystem's gross primary productivity (GPP). It is the total amount of energy fixed by autotrophs through photosynthesis. Therefore, the correct answer is option C: gross primary productivity.

Dense Forest Covers in India
The correct answer is option C: 11.4%.
Explanation:
India is known for its rich biodiversity and diverse forest cover. The percentage of dense forest cover in India, as a percentage of the total geographical area, is approximately 11.4%. Here's a detailed explanation of why option C is the correct answer:
Definition of Dense Forest Cover:
Dense forest cover refers to areas with a high density of trees and vegetation. It represents healthy and thriving ecosystems that support a wide range of flora and fauna.
Factors Determining Dense Forest Cover Percentage:
Several factors contribute to the percentage of dense forest cover in a country or region. These factors include:
1. Climate: Regions with high rainfall and favorable climatic conditions tend to have a higher percentage of dense forest cover.
2. Topography: Areas with varied topography, such as hills and mountains, often support dense forest cover.
3. Soil Fertility: Rich and fertile soil provides ideal conditions for the growth of dense forest cover.
4. Conservation Efforts: Government policies, conservation initiatives, and strict regulations play a crucial role in maintaining and increasing the dense forest cover.
Dense Forest Cover in India:
India has a diverse range of forests, including tropical rainforests, deciduous forests, alpine forests, and mangrove forests. The country is home to several national parks, wildlife sanctuaries, and protected areas that contribute to the conservation of dense forest cover.
Statistics:
According to the India State of Forest Report 2019, the total forest cover in India is approximately 21.67% of the total geographical area. Out of this, approximately 11.4% is classified as dense forest cover.
Conclusion:
India has made significant efforts in the conservation and preservation of its forest cover. While the dense forest cover percentage may vary in different regions of the country, the overall percentage is approximately 11.4% of the total geographical area. This highlights the importance of sustainable forest management and conservation practices to protect and enhance the dense forest cover in India.

"Noosphere" and "Bhagwan" - Concept Related to Environmental Ethics:
The concept of "Noosphere" and "Bhagwan" is related to Environmental Ethics. Here's a detailed explanation:
Noosphere:
1. Coined by French philosopher and Jesuit priest Pierre Teilhard de Chardin, the term "Noosphere" refers to the collective consciousness and intellectual activity of humanity.
2. The Noosphere concept suggests that human beings possess a unique capacity for rational thought, creativity, and innovation, which distinguishes them from other species.
3. It emphasizes the interconnectedness and interdependence of human beings and the environment, highlighting the role of human intellect in shaping and influencing the planet.
4. The Noosphere concept promotes the idea that humans have a responsibility to protect and preserve the environment, considering the long-term consequences of their actions.
Bhagwan:
1. In the context of Environmental Ethics, "Bhagwan" refers to the concept of divinity and reverence towards nature.
2. It is derived from the Indian philosophical and spiritual traditions, particularly the concept of "Bhagavan" in Hinduism.
3. The concept of Bhagwan implies recognizing the sacredness and intrinsic value of the natural world.
4. It encourages individuals to adopt an ethical approach towards the environment, treating it with respect, care, and gratitude.
5. Bhagwan promotes the idea of living in harmony with nature, avoiding exploitation and destruction.
Connection to Environmental Ethics:
1. Environmental Ethics is concerned with the moral principles and values that guide human interactions with the environment.
2. The concepts of "Noosphere" and "Bhagwan" both contribute to the foundation of Environmental Ethics by emphasizing the importance of human responsibility and ethical behavior towards the environment.
3. The Noosphere concept highlights the intellectual capacity of humans, urging them to use their knowledge and abilities to protect and preserve the environment.
4. The concept of Bhagwan promotes reverence towards nature, recognizing its intrinsic value and calling for ethical treatment of the environment.
5. Both concepts advocate for sustainable practices, conservation efforts, and a holistic approach to environmental issues.
In conclusion, the concepts of "Noosphere" and "Bhagwan" are related to Environmental Ethics as they emphasize the interconnectedness between humans and the environment, and the need for ethical behavior and responsibility towards nature.

Sea birds contribute significantly to the cycling of various nutrients in marine ecosystems. While they do play a role in the cycling of other nutrients such as nitrogen and carbon, their impact on the phosphorus cycle is particularly noteworthy. Here's how sea birds contribute to the phosphorus cycle:
1. Feeding Habits: Sea birds primarily feed on fish and marine invertebrates, which are rich sources of phosphorus. By consuming these organisms, sea birds accumulate phosphorus in their bodies.
2. Excretion: Sea birds excrete waste that contains high levels of phosphorus in the form of guano (bird droppings). Guano is known to be a valuable source of phosphorus, as it contains both organic and inorganic forms of the nutrient.
3. Guano Deposition: Sea birds often gather and nest in specific areas, forming large colonies. Over time, the accumulation of guano from these colonies results in thick layers of phosphorus-rich deposits on islands or coastal regions. These guano deposits serve as natural fertilizer, enriching the soil with phosphorus.
4. Runoff and Erosion: Rainwater and tidal action can cause guano deposits to wash into the surrounding marine environment. The phosphorus released from the guano can then be transported via runoff and erosion into nearby coastal waters, contributing to the nutrient availability in these ecosystems.
Overall, the activities of sea birds, especially their feeding habits, excretion, and the deposition of guano, play a vital role in the phosphorus cycle. Their contributions help to maintain the nutrient balance in marine ecosystems, supporting the growth of primary producers and sustaining the overall biodiversity of these habitats.

Pattern of distribution of species because analytical character is defined in a area or particular place.

Explanation:
The highest level of species richness is observed in tropical rain forests. Here's why:
Tropical Rain Forests:
- Tropical rain forests are characterized by high temperatures and abundant rainfall throughout the year, creating a favorable environment for diverse species.
- These forests are home to a wide range of plant and animal species, including many endemic species that are found nowhere else on Earth.
- The dense vegetation and complex structure of the rainforest provide various niches and habitats for different species to thrive.
- The warm and humid climate supports high levels of productivity and biomass, which in turn supports a large number of species.
- The continuous availability of resources and stable climate in tropical rainforests allow for the coexistence of numerous species, leading to high species richness.
Other Ecosystems:
- Temperate grasslands, coniferous forests, and alpine pastures have comparatively lower species richness.
- Temperate grasslands have a lower diversity of species due to their harsh and variable climate, limited water availability, and nutrient-poor soils.
- Coniferous forests, found in colder regions, have fewer species due to the extreme cold, longer winters, and lower nutrient availability.
- Alpine pastures are characterized by high altitudes and harsh conditions, which limit the number of species that can survive in such environments.
Conclusion:
In summary, tropical rain forests exhibit the highest level of species richness due to their favorable climate, diverse habitats, and abundant resources.

Explanation:
To understand the relationship between Dobson Units (DU) and ozone column thickness, we need to consider the definition of a Dobson Unit.
Definition:
- Dobson Unit (DU) is a unit of measurement used to quantify the total ozone amount in a vertical column of the Earth's atmosphere.
- It represents the thickness of the ozone layer if it were compressed and brought to a standard temperature and pressure.
- 1 DU is equivalent to the ozone column thickness that would be produced by 0.01 millimeters (mm) of pure ozone at standard temperature and pressure.
Now, let's convert the ozone column thickness from DU to parts per billion (ppb) using the given options:
- Option A: 0.1 ppb
- Option B: 1.0 ppb
- Option C: 0.01 ppb
- Option D: 0.001 ppb
To convert from DU to ppb, we need to multiply the ozone column thickness in DU by a conversion factor. The conversion factor can be obtained by considering the definition of 1 DU.
Conversion:
- 1 DU is equivalent to 0.01 mm of pure ozone at standard temperature and pressure.
- 1 mm is equal to 1,000,000 ppb (parts per billion).
Therefore, the conversion factor from DU to ppb is:
- Conversion factor = (0.01 mm * 1,000,000 ppb) / 1 DU
- Conversion factor = 10,000 ppb/DU
Now, let's calculate the ozone column thickness in ppb for each option using the conversion factor:
- Option A: 0.1 ppb = 0.1 ppb * (1 DU / 10,000 ppb/DU) = 0.00001 DU
- Option B: 1.0 ppb = 1.0 ppb * (1 DU / 10,000 ppb/DU) = 0.0001 DU
- Option C: 0.01 ppb = 0.01 ppb * (1 DU / 10,000 ppb/DU) = 0.000001 DU
- Option D: 0.001 ppb = 0.001 ppb * (1 DU / 10,000 ppb/DU) = 0.0000001 DU
Comparing the calculated values with the definition of 1 DU, we can see that the only option that matches the definition is Option B: 1.0 ppb. Therefore, the correct answer is B.

The Great Indian Bustard is found in the Thar Desert, which is located in northwestern India and southeastern Pakistan. Here is a detailed explanation of why the Thar Desert is the habitat of the Great Indian Bustard:
1. Geographic Range:
- The Great Indian Bustard is a large bird species that is endemic to the Indian subcontinent.
- Its geographic range primarily extends across the arid and semi-arid regions of India, including the Thar Desert.
2. Habitat Preference:
- The Thar Desert is characterized by vast expanses of arid and sandy terrain with sparse vegetation.
- This desert habitat provides the ideal conditions for the Great Indian Bustard, as it prefers open grasslands, scrublands, and semi-desert areas.
3. Food Availability:
- The Thar Desert is home to a variety of native plant species that serve as a food source for the Great Indian Bustard.
- The bird primarily feeds on grasses, seeds, insects, and small reptiles, which are abundant in the desert ecosystem.
4. Adaptations to Desert Life:
- The Great Indian Bustard has evolved several adaptations to survive in the harsh desert environment.
- It has long legs for walking and running across sandy terrain, helping it navigate the dunes of the Thar Desert.
- The bird also has specialized eyesight and hearing abilities that allow it to detect prey and predators in its vast habitat.
In conclusion, the Great Indian Bustard is found in the Thar Desert due to its geographic range, habitat preference, food availability, and adaptations to desert life. The arid conditions and sparse vegetation of the Thar Desert provide a suitable environment for this unique bird species to thrive.

Embryo culture is used for:
Embryo culture is a technique used in plant breeding and biotechnology to promote the growth and development of embryos in a controlled environment. It involves isolating embryos from seeds or ovules and providing them with the necessary nutrients and conditions for their growth. One of the main applications of embryo culture is the recovery of interspecific hybrids, which refers to the crossing of two different species. The embryos resulting from such crosses often have low viability or do not develop fully, making it difficult to obtain viable plants. Embryo culture can help overcome these challenges and facilitate the successful development of interspecific hybrids.
Some other applications of embryo culture include:
- Somatic hybridization: This technique involves fusing protoplasts (cellular components) from different plant species and inducing them to form embryos. Embryo culture is then used to promote the growth and development of these embryos into mature plants. Somatic hybridization allows for the transfer of desirable traits between plant species that are not easily crossable through traditional breeding methods.
- Haploid production: Haploids are plants that have only one set of chromosomes instead of the usual two sets. Haploids can be used in plant breeding to develop homozygous lines more quickly. Embryo culture can be used to induce the production of haploid embryos, which can then be treated with chemicals or irradiation to double their chromosome number and create homozygous plants.
In conclusion, embryo culture is primarily used for the recovery of interspecific hybrids, but it also has applications in somatic hybridization and haploid production.

Answer:
The Pusa-RH-10 variety of rice is produced through the process of hybridization. Here is a detailed explanation of how hybridization is used to produce this variety of rice:
What is Hybridization?
Hybridization is a breeding technique that involves crossing two genetically distinct parent plants to create offspring with desirable traits. This process aims to combine the best characteristics from both parent plants to produce a new variety that is superior in terms of yield, disease resistance, quality, or other desirable traits.
Steps in Hybridization:
1. Selection of parent plants: Two genetically diverse parent plants are selected based on their desirable traits. In the case of Pusa-RH-10 rice, specific parent plants with traits like high yield, disease resistance, and good grain quality are chosen.
2. Cross-pollination: The selected parent plants are cross-pollinated by manually transferring pollen from the male flower of one plant to the stigma of the female flower of another plant. This process ensures the fusion of genetic material from both parent plants.
3. Hybrid seed production: After successful cross-pollination, the plants produce hybrid seeds. These seeds contain a combination of genetic material from both parent plants.
4. Field trials and evaluation: The hybrid seeds are grown in test plots to evaluate their performance. Factors like yield, disease resistance, and quality of the resulting plants are assessed to determine the potential of the hybrid variety.
5. Selection and multiplication: The best-performing plants from the field trials are selected for further multiplication. These plants are grown in larger quantities to produce sufficient seeds of the hybrid variety.
6. Release and adoption: Once the hybrid variety has been thoroughly evaluated and proven to be superior, it is released for commercial cultivation. Farmers can then adopt this new variety of rice and benefit from its improved traits.
Therefore, in the case of the Pusa-RH-10 variety of rice, it is produced through the process of hybridization, which involves crossing two genetically distinct parent plants to create offspring with desirable traits.