ROUTERA

Our Environment

Class 10th Science Chapter Assertion and Reason

Our Environment

  • Options:
    a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
    b) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
    c) Assertion (A) is true, but Reason (R) is false.
    d) Assertion (A) is false, but Reason (R) is true.

Question 1

Assertion (A): Biodiversity is essential for a balanced ecosystem.
Reason (R): Higher biodiversity enhances ecosystem productivity and stability.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Biodiversity contributes to various ecosystem services, ensuring resilience and the ability to recover from disturbances, thus maintaining ecological balance.

Question 2

Assertion (A): Ozone depletion is primarily caused by chlorofluorocarbons (CFCs).
Reason (R): CFCs release chlorine atoms when they break down in the stratosphere, which destroys ozone molecules.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: CFCs, once used in refrigeration and aerosol sprays, release chlorine upon degradation, leading to the depletion of the ozone layer, which protects Earth from harmful UV radiation.

Question 3

Assertion (A): Water pollution can have detrimental effects on aquatic life.
Reason (R): Polluted water can introduce toxins and disrupt the food chain in aquatic ecosystems.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Contaminants in water can harm aquatic organisms, causing bioaccumulation of toxins, which affects predator species and disrupts the entire food chain.

Question 4

Assertion (A): The greenhouse effect is a natural phenomenon.
Reason (R): It is essential for maintaining Earth's temperature by trapping heat in the atmosphere.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: The greenhouse effect helps keep Earth warm enough to support life; however, human activities have intensified this effect, leading to climate change.

Question 5

Assertion (A): Deforestation contributes to climate change.
Reason (R): Trees absorb carbon dioxide, a greenhouse gas, during photosynthesis.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Deforestation leads to higher carbon dioxide levels in the atmosphere since fewer trees are available to absorb it, thereby exacerbating climate change.

Question 6

Assertion (A): Organic farming is considered more environmentally friendly than conventional farming.
Reason (R): Organic farming avoids the use of synthetic fertilizers and pesticides, promoting biodiversity.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Organic farming practices reduce chemical runoff and pollution, supporting healthy ecosystems and promoting biodiversity compared to conventional farming.

Question 7

Assertion (A): Landfills can contribute to groundwater pollution.
Reason (R): Decomposing organic waste produces leachate, which can seep into groundwater.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: The leachate produced in landfills contains harmful substances that can contaminate groundwater sources, posing risks to drinking water quality.

Question 8

Assertion (A): Air pollution can lead to respiratory diseases in humans.
Reason (R): Pollutants like particulate matter can irritate the respiratory tract and cause inflammation.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Exposure to air pollutants can exacerbate pre-existing respiratory conditions and increase the risk of diseases such as asthma and bronchitis.

Question 9

Assertion (A): Eutrophication is a process that can lead to oxygen depletion in water bodies.
Reason (R): Excess nutrients in water promote algal blooms, which consume oxygen during decomposition.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: When algal blooms die, their decomposition depletes dissolved oxygen in the water, leading to hypoxic conditions that can harm aquatic life.

Question 10

Assertion (A): The introduction of non-native species can disrupt local ecosystems.
Reason (R): Non-native species often compete with native species for resources, leading to a decline in native populations.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Non-native species can outcompete native species for food and habitat, causing imbalances in the ecosystem and potentially leading to extinctions.

Question 11

Assertion (A): Biodegradable waste can be composted to reduce landfill use.
Reason (R): Composting transforms organic waste into nutrient-rich soil amendment through microbial decomposition.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Composting organic waste not only diverts it from landfills but also enriches the soil, enhancing its fertility and structure.

Question 12

Assertion (A): Plastic pollution poses a significant threat to marine life.
Reason (R): Marine animals can ingest plastic debris, leading to injury or death.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Many marine species mistake plastic for food, leading to ingestion that can block their digestive systems and cause various health issues.

Question 13

Assertion (A): The use of fossil fuels contributes to environmental degradation.
Reason (R): Fossil fuel combustion releases greenhouse gases and other pollutants into the atmosphere.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Burning fossil fuels results in emissions that contribute to air pollution and climate change, negatively impacting ecosystems and human health.

Question 14

Assertion (A): Conservation efforts are necessary to protect endangered species.
Reason (R): Endangered species play vital roles in their ecosystems and contribute to biodiversity.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Protecting endangered species is crucial for maintaining ecological balance and preserving biodiversity, which is essential for ecosystem resilience.

Question 15

Assertion (A): Urbanization can lead to habitat destruction.
Reason (R): Expansion of cities requires land that may be home to various species.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Urban development often encroaches on natural habitats, leading to the displacement and loss of wildlife populations, thereby impacting biodiversity.

Question 16

Assertion (A): The carbon cycle is essential for life on Earth.
Reason (R): The carbon cycle regulates the flow of carbon through various reservoirs, including the atmosphere and oceans.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: The carbon cycle maintains the balance of carbon in the environment, facilitating processes like photosynthesis and respiration, which are critical for sustaining life.

Question 17

Assertion (A): Environmental education is crucial for promoting sustainability.
Reason (R): It raises awareness about environmental issues and encourages responsible behavior towards natural resources.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: By educating individuals about environmental challenges, we foster a sense of responsibility and empowerment to make sustainable choices.

Question 18

Assertion (A): Noise pollution can adversely affect human health.
Reason (R): Prolonged exposure to loud noise can lead to stress, hearing loss, and sleep disturbances.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Noise pollution can cause various health problems, including cardiovascular issues and mental health concerns, highlighting the importance of maintaining a quieter environment.

Question 19

Assertion (A): Climate change is primarily driven by human activities.
Reason (R): Industrial processes and deforestation increase greenhouse gas emissions, leading to global warming.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Human actions such as burning fossil fuels and clearing forests release significant amounts of greenhouse gases, significantly contributing to climate change.

Question 20

Assertion (A): Sustainable development aims to meet the needs of the present without compromising future generations.
Reason (R): It involves balancing economic growth, environmental protection, and social equity.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Sustainable development seeks to create a harmonious relationship between human development and the health of the planet, ensuring resources are available for future generations.