- (a) Biological factors
- (b) Abiotic factors
- (c) Biotic factors
- (d) Physical factors
Answer:
(c) Biotic factors
- (a) Evaporation
- (b) Condensation
- (c) Sublimation
- (d) Infiltration
Answer:
(c) Sublimation
- (a) Photosynthesis
- (b) Assimilation
- (c) Respiration
- (d) Decomposition
Answer:
(a) Photosynthesis
- (a) Carbon monoxide
- (b) Sulphur dioxide
- (c) Nitrogen dioxide
- (d) Carbon dioxide
Answer:
(d) Carbon dioxide
| Microorganism | Role |
|---|---|
| *Nitrosomonas* | Nitrification |
| *Azotobacter* | Nitrogen fixation |
| *Pseudomonas* species | Denitrification |
| Putrefying bacteria | Ammonification |
If false, correct the statement.
Answer: False
Correct Statement:
Carbon dioxide and methane are important greenhouse gases.
Answer: False
Correct Statement:
Poorly developed roots are adaptation of hydrophytes.
Answer: True
Answer: False
Correct Statement:
Bats use echolocation through ultrasonic sounds.
Answer: False
Correct Statement:
Aestivation helps organisms survive hot and dry conditions.
Answer:
Xerophytes grow in dry habitats where water is scarce.
Deep roots help them absorb water from deeper soil layers.
Answer:
- Streamlined body helps movement through soil.
- Setae provide grip and anchorage in burrows.
Answer:
- Farm ponds occupy large area of land.
- They may reduce water availability to nearby lower fields and ponds.
Answer:
(i) Biotic Factors
Living components:
- plants
- animals
- microorganisms
(ii) Abiotic Factors
Non-living components:
- air
- water
- sunlight
- temperature
- soil
Answer:
Human activities:
- Alter biodiversity
- Disturb food chains
- Destroy habitats
- Increase pollution
Answer:
Special feature helping organism survive in its habitat is called adaptation.
Answer:
- Excess water availability
- Water current damage
- Changing water levels
- Need for buoyancy
Answer:
- Water is precious natural resource
- Essential for all living organisms
- Freshwater availability is limited
Answer:
- Repair leaking taps
- Use low-flow taps
- Reuse water
- Use recycled water for gardens
Answer:
- Agriculture
- Public parks
- Construction
- Cooling in industries
- Toilet flushing
Answer:
IUCN stands for:
International Union for Conservation of Nature
Vision of IUCN
“A just world that values and conserves nature.”
# Water Cycle
Continuous movement of water between earth and atmosphere.
(i) Evaporation
Water changes from liquid to vapour.
Occurs from:
- oceans
- lakes
- rivers
(ii) Sublimation
Ice directly changes into vapour.
Examples:
- polar ice caps
- mountain glaciers
(iii) Transpiration
Plants release water vapour through stomata.
(iv) Condensation
Water vapour cools and forms clouds.
(v) Precipitation
Water falls as:
- rain
- snow
- hail
(vi) Runoff
Rainwater flows into rivers and oceans.
(vii) Infiltration
Water enters soil.
(viii) Percolation
Water moves through porous rocks underground.
# Steps in Carbon Cycle
- Atmospheric (CO_2) absorbed by plants through photosynthesis
- Carbon transferred to animals through food chain
- Respiration releases (CO_2)
- Decomposition releases carbon compounds
- Burning fossil fuels releases carbon dioxide
# Simple Flow Chart
Answer:
- Deep root system
- Thick waxy cuticle
- Leaves reduced to spines
- Water-storing tissues
- Short life cycle during rainy season
Examples:
- Opuntia
- Aloe vera
- Acacia
Answer:
- Live in caves
- Nocturnal habit
- Use echolocation
- Undergo hibernation
- Wings adapted for flight
# Definition
Reuse of treated wastewater for beneficial purposes.
Wastewater Treatment Stages
# (i) Primary Treatment
Removal of large solid particles.
# (ii) Secondary Treatment
Microorganisms decompose organic wastes.
# (iii) Tertiary Treatment
Chemical disinfection and purification.
Uses of Recycled Water
- irrigation
- industries
- parks
- construction
Demonstration of Water Cycle
Aim
To understand water recycling and water cycle.
Materials
- Large transparent bowl
- Plastic wrap
- Rubber band
- Small container
- Stone
Procedure
- Place small bowl inside large bowl.
- Add water into large bowl.
- Cover with plastic wrap.
- Keep stone on top.
- Place under sunlight.
Observation
- Water droplets form on plastic wrap → condensation
- Water level decreases → evaporation
- Droplets fall into bowl → precipitation
Conclusion
Processes demonstrated:
- evaporation
- condensation
- precipitation
# Greenhouse Effect
Trapping of heat by greenhouse gases.
Major Greenhouse Gases
- Carbon dioxide
- Methane
- Nitrous oxide
# Global Warming
Increase in earth’s average temperature due to greenhouse effect.
# Nitrogen Cycle
Movement of nitrogen through atmosphere, soil and organisms.
Important Processes
- Nitrogen fixation
- Nitrification
- Assimilation
- Ammonification
- Denitrification
# Types of Plants Based on Habitat
| Plant Type | Habitat |
|---|---|
| Hydrophytes | Aquatic |
| Xerophytes | Desert |
| Mesophytes | Moderate conditions |
# Important Summary
Biotic Factors
Living components of ecosystem.
Abiotic Factors
Non-living environmental factors.
Water Cycle
Movement of water between atmosphere and earth.
Carbon Cycle
Movement of carbon through environment.
Adaptation
Feature helping survival in habitat.
Xerophytes
Plants adapted to dry habitats.
Hydrophytes
Plants adapted to aquatic habitats.
Echolocation
Navigation using reflected sound waves.
# Grade 9 Computer Science
Revise Environmental Science faster.
Use these expandable textbook answers for homework, quick revision, and exam preparation.