🌟 Class
8 Science – Curiosity Chapter 13
🌍 Our
Home: Earth, a Unique Life Sustaining Planet
🟢 1.
What is one major reason Mars cannot currently support life like Earth?
✅
Answer:
👉 (iii)
It lacks a thick atmosphere and liquid water
🧠 Explanation:
- Mars
has a very thin atmosphere
- Cannot
trap heat 🌡️
- No
stable liquid water 💧
📌 These
conditions make life impossible ✔️
🟢 Class
8 Science Curiosity Chapter 13 Question 2, 3 and 4
🟢 2.
Which of these is an example of geodiversity?
✅
Answer:
👉 (ii)
Different landforms like mountains, valleys, and deserts
🧠 Explanation:
- Geodiversity
= non-living features
- Includes
rocks, soil, landforms 🪨
🟢 3. If
the Earth were smaller with the same density, what might happen to its
atmosphere?
✅
Answer:
👉 (ii)
It would escape into space due to weaker gravity
🧠 Explanation:
- Smaller
size → weaker gravity
- Cannot
hold gases 🌬️
- Atmosphere
escapes into space
🟢 4. In
sexual reproduction, why are offspring different from their parents?
✅
Answer:
👉 (iv)
They get mixed instructions (genes) from both parents
🧠 Explanation:
- Genes
from both parents combine 🧬
- Creates
variation (भिन्नता)
🟢
Question 5 and 6 of Class 8 Science Curiosity Chapter 13
🟢 5. You
notice tiny green plants growing in cracks on your school wall after the
monsoon. Where do you think the seeds came from? What conditions helped these
plants grow there?
✅
Answer:
🌱 Source
of seeds:
- 🌬️
Carried by wind
- 🐦
Dropped by birds
🌧️ Favourable
conditions:
- Moisture
from rain 💧
- Dust/soil
in cracks 🌱
- Sunlight
☀️
- Air
🌬️
🟢 6. A
city has recently cut down a large patch of forest to build new roads and
buildings. Discuss the possible effects this could have on the local climate
and biodiversity? How might this affect water availability or quality in the
area?
✅
Answer:
🌡️
Effects on Climate:
- Temperature
increases 🔥
- Rainfall
decreases 🌧️
🐾
Effects on Biodiversity:
- Loss
of habitat 🏚️
- Animals
migrate or die ❌
- Biodiversity
decreases 📉
💧
Effects on Water:
- Less
groundwater recharge ⬇️
- Soil
erosion 🌊
- Water
pollution increases ⚠️
🟢 Class
8 Science Curiosity Chapter 13 Question 7, 8 and 9
🟢 7. A
friend says, “The Earth has always had climate changes in the past, so today’s
global warming is nothing new.” How would you respond?
✅
Answer:
🧠 Response:
- ⚡ Much faster
- 👨🏭
Caused by human activities
🟢 8.
Imagine Earth’s magnetic field suddenly disappeared. What kinds of problems
could arise for life on Earth?
✅
Answer:
🛡️
Magnetic field = protective shield
❌
Without it:
- ☀️ Solar wind damages
atmosphere
- 🌌
Harmful radiation reaches Earth
- 🧬
Cells get damaged
🟢 9. You
are tasked with designing a new settlement for humans on Mars. Name three
things you would need to recreate from Earth. Which is hardest?
✅
Answer:
🌍
Needed:
1.
🌬️
Breathable atmosphere
2.
💧 Liquid
water
3.
🌱 Food
system
⚠️
Hardest:
👉 Atmosphere
🧠
Reason:
- Requires
planet-level change
- Very
complex & large-scale
🟢 Class
8 Science Curiosity Chapter 13 Question 10, 11 and 12
🟢 10. In
a village, temperature is increasing and rainfall is unpredictable. What could
be causing this? Suggest two solutions.
✅
Answer:
🌡️
Causes:
- Global
warming 🌍
- Deforestation
🌳❌
🌱
Solutions:
1.
💧
Rainwater harvesting
2.
🌳 Tree
plantation (Afforestation)
🟢 11. If
there were no atmosphere on the Earth, would it affect life, temperature and
water?
✅
Answer:
❌ Effect
on Life:
- No
oxygen 🫁
- No
protection from UV rays ☀️
🌡️ Effect
on Temperature:
- Extreme
heat & cold 🔥❄️
💧 Effect
on Water:
- No
liquid water
- Either
freeze or evaporate
🟢 12.
Discuss five examples of vegetative propagation.
✅
Answer:
🌱 Examples:
1.
🥔 Potato
→ from
eyes
2.
🌿 Ginger
→
rhizome
3.
🪴 Money
plant → stem
cutting
4.
🌾
Sugarcane → stem (setts)
5.
🌹 Rose → stem
cutting
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