Track quiz
Show on a big screenBefore the questions, here are the nine rules this track worked with.
| Idea | The rule, as the lab applies it |
|---|---|
| A place in the middle | Earth is at the right distance from the Sun. Water can stay liquid here. Closer, it would boil away. Farther, it would freeze. |
| The blanket of air | Earth's gravity is strong enough to keep its air. A much smaller planet, of the same density, has weak gravity. It can lose its air. The ozone layer blocks harmful ultraviolet rays. |
| Water everywhere | Water covers about 70 per cent of Earth's surface. All the water together is the hydrosphere. Rain and snow refill rivers, lakes and underground water. |
| The thin layer on top | Rocks, soil and minerals make up the geosphere. Soil comes from broken rock and the remains of plants and animals. It holds nutrients that plants need. |
| The neighbours | Farther planets are generally colder. But Venus is the hottest, because its thick air traps heat. Mercury has almost no air. |
| Several at once | Earth has the right distance, the right size and a magnetic field. The magnetic field pushes many harmful particles away. Lose any one, and life is at risk. |
| Looking after Earth | Burning fossil fuels adds carbon dioxide to the air. Extra carbon dioxide traps heat and warms the planet. Using less fuel slows the warming. |
| One parent or two | In asexual reproduction, one parent makes young that match it. In sexual reproduction, gametes from two parents join. The young get a mix, so they usually differ from both parents. |
| Flower to seed | Pollination moves pollen to a flower. Fertilisation is when a male gamete and a female gamete join. The ovule then becomes a seed. |
A planet is at a good distance from its star. Its air is almost gone. What is likely?
A planet is much closer to the Sun than Earth. What happens to its water?
Two planets have the same density. One is much smaller. Which can lose its air more easily?
What does the ozone layer do?
Rivers, lakes and oceans belong to which part of Earth?
Which is an example of geodiversity?
What is soil made from?
Why is Venus hotter than Mercury?
Earth's magnetic field disappears. What is the danger?
Why does burning coal and oil warm the planet?
Why do young plants grown from seeds usually differ from their parents?
Pollen lands on a flower. What has happened so far?
Now read the chapter in your NCERT book.
Reveal every answer to finish this lesson.
That is the end of this subject for Class 8
Nicely done. There is more waiting at this same level — pick whichever you like.