Conservation of Plants and Animals – Case-based Questions with Answers
CBSE Class 8 Science — Chapter 7: Conservation of Plants and Animals
- Read NCERT theory and mark key definitions, diagrams and examples.
- Understand in-situ vs ex-situ conservation, laws and major projects (e.g., Project Tiger).
- Practice case-based questions to apply concepts to real-life scenarios; memorise a few protected areas and examples.
20 Case-Based Questions & Model Answers
Case 1 — Yellowing Forest Patch
Villagers report a nearby forest patch where many trees are dying and bird diversity has reduced over two years.
Questions:
- List two possible causes for tree mortality and loss of bird diversity.
- Suggest two conservation actions to investigate and mitigate the problem.
Answer: Possible causes: (1) Disease outbreak or pest infestation; (2) Pollution or changes in groundwater/soil quality due to nearby development. Conservation actions: (1) Conduct ecological assessment and soil/water tests; (2) Restrict harmful activities, treat affected trees if possible, and restore with native species while monitoring bird populations.
Case 2 — Farmers Burning Stubble
After harvest, farmers burn crop residues to clear fields quickly; nearby town experiences seasonal air pollution spikes.
Questions:
- Explain environmental impacts of stubble burning.
- Recommend two sustainable alternatives for farmers.
Answer: Impacts: releases smoke and particulate matter harming human health and reduces soil organic matter. Alternatives: (1) Leave residues as mulch or incorporate into the soil to improve fertility; (2) Use residues for composting, biochar or as biomass for bioenergy, plus government-supported machinery for residue management.
Case 3 — A Poached Elephant
An elephant carcass with tusks removed is found in a forest reserve.
Questions:
- Identify immediate conservation priorities.
- Suggest long-term measures to prevent poaching.
Answer: Immediate priorities: secure the site, document evidence and report to wildlife authorities. Long-term measures: strengthen anti-poaching patrols, community awareness and alternative livelihoods, use of technology (camera traps, GPS collars), and stricter enforcement against illegal ivory trade via laws and international cooperation.
Case 4 — Aquarium Release
A well-meaning hobbyist releases a non-native aquarium fish into a local pond.
Questions:
- What ecological risks can this action cause?
- How should authorities respond and educate the public?
Answer: Risks: invasive species may outcompete native fish, spread disease, and alter food webs. Response: remove and contain the species if possible, monitor pond ecology, and run public campaigns against releasing pets; promote surrender programs where hobbyists can return unwanted species to aquaria or conservation centres.
Case 5 — Seed Bank Proposal
A local NGO proposes a seed bank to conserve native crop varieties threatened by modern hybrids.
Questions:
- List benefits of a community seed bank.
- Describe two key management practices for seed preservation.
Answer: Benefits: preserves genetic diversity, supports local food security and provides material for crop breeding. Management practices: (1) Proper drying and cold storage to maintain viability; (2) Regular germination testing and documentation of provenance, plus community seed-sharing policies to maintain use and relevance.
Case 6 — Wetland Drainage Plan
A development plan proposes draining a small wetland for construction.
Questions:
- Explain ecological services provided by wetlands.
- Suggest alternatives that balance development and conservation.
Answer: Services: wetlands filter pollutants, store floodwaters, provide habitat for birds and fish, and support fisheries. Alternatives: redesign project to avoid wetland, create engineered wetlands for stormwater management, or implement mitigation like creating compensatory wetlands and relocating development to less sensitive sites.
Case 7 — Community Forest Success
A village reports improved forest cover and wildlife sightings after a community-managed forest programme.
Questions:
- Explain why community involvement can succeed in conservation.
- List two practices that likely contributed to success.
Answer: Community involvement succeeds because locals have stakes and Traditional Knowledge; ownership increases stewardship. Practices: sustainable harvest regulations, periodic patrols, alternative livelihoods (non-timber forest products, eco-tourism) and benefit-sharing that align conservation with local welfare.
Case 8 — Fish Kill After Pesticide Runoff
After heavy rains, a river downstream of agricultural land shows massive fish deaths.
Questions:
- Identify the probable cause.
- Propose two measures to prevent recurrence.
Answer: Probable cause: pesticide and fertilizer runoff causing oxygen depletion or toxin exposure. Measures: create buffer strips of vegetation, promote integrated pest management to reduce chemical use, and construct retention ponds to trap runoff before it reaches rivers.
Case 9 — Zoo Breeding Programme
A zoo claims success in captive breeding of a near-extinct species and proposes reintroduction.
Questions:
- What steps are necessary before reintroduction?
- What are risks and how can they be minimised?
Answer: Steps: ensure suitable protected habitat, health screening, behavioural conditioning, genetic assessment and post-release monitoring. Risks: disease spread, failure to adapt, human-wildlife conflict; minimise via soft-release techniques, community involvement and habitat restoration to support survival.
Case 10 — Illegal Timber Trade Alert
Authorities intercept a truck with illegally cut timber from a protected forest.
Questions:
- Describe ecological consequences of illegal logging.
- Suggest enforcement and community measures to reduce illegal logging.
Answer: Consequences: habitat loss, erosion, reduced biodiversity and disruption of water cycles. Measures: stricter patrols and penalties, timber traceability systems, community forestry rights with legal harvesting quotas, and livelihood alternatives to reduce dependency on illegal timber.
Case 11 — Road Cutting Through Forest
Proposal to build a new road through a wildlife corridor is under public consultation.
Questions:
- Analyse potential impacts on wildlife movement.
- Recommend design changes to reduce impact.
Answer: Impacts: barrier to movement, increased roadkill, noise disturbance and fragmentation. Recommendations: reroute to avoid core corridor, build wildlife underpasses/overpasses, enforce speed limits and nighttime restrictions, and conduct environmental impact assessment before construction.
Case 12 — Farmer Wants to Plant Exotic Trees
A farmer intends to plant fast-growing exotic trees (like eucalyptus) on a community grazing land.
Questions:
- Discuss ecological pros and cons of exotic monocultures.
- Suggest more biodiversity-friendly alternatives.
Answer: Pros: quick timber yield and income. Cons: reduced native biodiversity, soil degradation, water depletion and habitat loss. Alternatives: mixed native species plantations, agroforestry integrating fodder and fruit trees, and native species that support local fauna while providing economic returns.
Case 13 — School Lake Clean-Up
Students organise a clean-up of a small urban lake and plan to plant native trees along the bank.
Questions:
- Explain ecological benefits of planting native trees by the lake.
- Suggest two monitoring activities students can undertake to measure success.
Answer: Benefits: reduces erosion, provides habitat for birds and insects, filters runoff and improves water quality. Monitoring: regular surveys of bird/insect species and water quality testing (pH, turbidity) to track improvements; photograph banks to document vegetation growth.
Case 14 — Overcrowded Sanctuary
A wildlife sanctuary receives far more tourists than its capacity, disturbing animals and creating litter.
Questions:
- What negative effects does overtourism have on conservation?
- Recommend two management actions to reduce impact while maintaining community benefits.
Answer: Negative effects: disturbance to wildlife, habitat degradation and pollution. Actions: implement visitor limits, zoning and guided tours to concentrate activities; introduce entry fees and revenue-sharing with locals to fund conservation; provide education for tourists and improve waste management facilities.
Case 15 — Coastal Mangrove Clearing
Coastal development plans include clearing mangroves for a tourist complex.
Questions:
- Explain why mangroves are important to coastal ecosystems.
- Recommend sustainable approaches for coastal development.
Answer: Mangroves protect shorelines from erosion, serve as nurseries for fish, store carbon and support biodiversity. Sustainable approaches: avoid clearing mangroves, use setback zones, design on stilts or reclaimed areas away from critical habitats, and invest in eco-tourism that conserves mangroves while supporting livelihoods.
Case 16 — Illegal Pet Trade Bust
Customs intercept a shipment of live reptiles suspected for illegal pet trade.
Questions:
- How does illegal wildlife trade threaten conservation?
- What coordinated measures can reduce transnational wildlife trafficking?
Answer: Threats: removal of individuals from wild populations reduces numbers and genetic diversity, risks species survival and funds criminal networks. Measures: strengthen customs screening, international cooperation and information-sharing, stiff penalties, demand reduction through awareness, and regulated rescue/rehabilitation centres for confiscated animals.
Case 17 — Restoration of Degraded Grassland
A district plans to restore degraded grassland to support grazing and biodiversity.
Questions:
- Outline steps for ecological restoration.
- How can local pastoralists be involved positively?
Answer: Steps: assess baseline conditions, remove invasive species, reintroduce native grasses, manage grazing intensity and monitor recovery. Involve pastoralists via rotational grazing plans, benefit-sharing, and training in sustainable grazing to align livelihoods with restoration goals.
Case 18 — Decline of Pollinators in Orchard
Farmers report fewer bees and lower fruit yields in an orchard after pesticide use increased.
Questions:
- Explain link between pesticides and pollinator decline.
- Suggest two farming practices to support pollinators and improve yields.
Answer: Pesticides can be toxic to bees, killing adults or disrupting foraging and reproduction. Practices: adopt integrated pest management to minimise chemical use, plant flowering strips or hedgerows as pollinator habitats, and use selective, less-toxic pesticides applied during times when bees are less active.
Case 19 — Urban Green Roof Initiative
A city encourages green roofs to increase urban biodiversity and reduce heat islands.
Questions:
- What biodiversity and climatic benefits do green roofs provide?
- How can the city ensure native species are used effectively?
Answer: Benefits: provide habitat for insects and birds, reduce runoff, insulate buildings and lower urban temperatures. Ensure native species by offering guidelines and incentives for native plant use, training installers, and creating nursery partnerships to supply local native plants suitable for rooftop conditions.
Case 20 — School Campaign Against Illegal Bird Egg Collection
Students discover locals collecting bird eggs for sale and start an awareness campaign.
Questions:
- Explain why egg collection is harmful to bird populations.
- Propose steps the school can take to reduce this practice.
Answer: Harm: removes future generations, reducing recruitment and risking local population declines. Steps: awareness drives, community dialogues, involve local leaders, report to wildlife authorities, and offer alternatives like egg-safe income sources (e.g., guided nature walks) and nest-protection programmes that pay locals to guard nests.
These case-based questions and answers are aligned with NCERT Chapter 7 and designed to sharpen application, analysis and exam-ready responses for CBSE Class 8.