What term refers to a self-regulating and self-sustaining unit of the biosphere?

1. Ecosystem
2. Food cycle
3. Biome
4. Ecology

Name the cycle through which solar energy moves from non-living to living organisms and back.

1. Carbon cycle
2. Nitrogen cycle
3. Nutrition cycle
4. Energy cycle

Name the genius Indian mathematician astronomer from the ancient world who was the first proponent of the round shape of the earth.

1. Pythagoras
2. Aryabhatta
3. Brahmagupta
4. Bhaskara

You are standing at a beach looking towards the horizon. You hear the horn of a ship. Which part of the ship will you see first?

1. Hull
2. Deck
3. Mast
4. All of them.