Exercises
Step 2: Very Short Questions
a. In the diagram, A is called an extinct species because its population has reached zero.
b. The plant shown in the diagram is Ghodtapre, which is also known as Asiatic Pennywort.
c. Excessive greenhouse gases cause a rise in atmospheric temperature, making it difficult for species to adapt and eventually leading to their extinction.
d. If the concentration of carbon dioxide increases, it traps more solar heat in the atmosphere, leading to global warming and climate change.
e.
• Extinct species have a population of zero.
• Endangered species have a population that is decreasing and may reach zero in the future.
f. We should not consume excessive Bojho because it contains psychoactive chemicals that can be harmful if taken in large amounts.
g. Examples of protected species in Nepal are:
• Impeyan pheasant (bird)
• Red Panda (mammal)
• Gharial (reptile)
h. Wildlife conservation is necessary because the loss of wildlife causes serious disruption in the ecosystem and natural balance.
i. The kind of conservation practice, where animals are protected and kept in a controlled environment like a zoo rather than their natural habitat, is called ex-situ conservation..
Step 3: Short Questions
a.
The main cause of this tragedy is human-induced climate change, which involves long-term changes in temperature and rainfall. Activities responsible for this include:
• Burning fossil fuels in industries and vehicles
• Deforestation for farming and timber
• Excessive use of gadgets like air conditioners and refrigerators
• Decomposition of waste in landfills releasing harmful gases
b.
Human activities reduce wildlife populations through:
• Illegal hunting and poaching for skin, bones, and tusks
• Destruction of natural habitats due to urbanization and industrialization
• Overgrazing by domestic animals and introduction of hybrid species
• Environmental pollution from plastics and chemical fertilizers
c.
Drinking Tulsi water improves health because Tulsi has antimicrobial and antibiotic properties. Its benefits include:
• Treatment of fever and common cold
• Improvement of skin problems like acne and blackheads
• Relief from insect bites
• Treatment of respiratory problems such as bronchitis and asthma
d.
Riding a motorbike for a short distance of 2 km is not wise because vehicles burn fossil fuels and release greenhouse gases. These gases trap heat in the atmosphere, causing global warming, which leads to rising sea levels and extreme weather conditions. To protect the environment, Mr. Khadka should walk or cycle for short distances. He can also use electric vehicles to reduce pollution and carbon emissions. Responsible travel choices help slow climate change.
e. Difference between Greenhouse Effect and Climate Change
Greenhouse Effect:
• Process by which infrared radiation warms the lower atmosphere
• Mainly caused by gases like carbon dioxide, methane, and water vapour
• Essential for maintaining a suitable temperature for life on Earth
• Refers specifically to heat trapping in the atmosphere
Climate Change:
• Long-term change in weather patterns such as temperature and rainfall
• Caused by natural factors and human-induced global warming
• Currently occurring at a rapid pace due to human activities
• Leads to ecosystem destruction and extreme weather events
f.
The main cause of this situation is over-collection of medicinal herbs and destruction of their natural habitats. To increase the use of medicinal herbs, we should:
• Use modern conservation methods like in-situ and ex-situ conservation
• Apply genetic technology to increase plant populations
• Conduct awareness programs about the value of local herbs
• Protect natural habitats required for their growth
g.
Forest fires are the burning of forest areas that release stored carbon into the atmosphere. Mrs. Khatri is incorrect because trees absorb carbon dioxide and release oxygen. Burning forests increases greenhouse gases, accelerating climate change and global warming. Forest fires also destroy wildlife habitats, disrupt ecosystems, and cause disasters like droughts.
h.
To minimize climate change in Nepal, the following measures should be implemented:
• Promote renewable energy such as solar and wind power
• Strengthen forest protection laws
• Encourage sustainable transport and electric vehicles
• Reduce plastic use due to its high carbon footprint
Step 4: Long Questions
a.
Malabar nut (Aasuro) is a perennial, evergreen, bushy shrub that grows up to about 2 m in height. It is found in the Himalayan plains of Nepal up to 1300 m altitude. Its uses include:
• Treatment of cough, cold, and asthma
• Use as a poultice for joint pain and inflammation
• Treatment of tuberculosis and fever when taken with honey or warm water
• Improvement of oral health and bleeding gums
It has antimicrobial properties and no major side effects have been reported.
b.
Climate change causes biodiversity loss by rapidly altering environmental conditions. Rising temperatures make it difficult for plants and animals to adapt, increasing the risk of extinction. Disasters such as floods and droughts destroy habitats and food sources. Human-induced warming happens so fast that species cannot adjust, threatening rare and indigenous organisms.
c.
Glacial lake flooding is linked to climate change because increased greenhouse gases raise global temperatures. This causes glaciers and ice caps to melt rapidly, forming unstable glacial lakes. When these lakes burst, they cause floods and landslides. Melting glaciers also contribute to rising sea levels, endangering coastal regions.
d.
Applying Aloe vera gel is beneficial because it helps heal burns and wounds. Other uses include:
• Treatment of constipation using dried latex
• Use in commercial foods like yogurt and desserts
• Use as a moisturizer in cosmetics
• Supply of Vitamins A and C and essential minerals
e.
Hunting rhinos is illegal because they are protected animals, and poaching destroys ecosystems. To prevent their extinction:
• Strictly ban illegal hunting
• Conserve and restore natural habitats
• Conduct awareness programs
• Encourage community participation in conservation
• Use modern techniques like genetic technology and managed environments