Carbon Cycle

Q. Which of the following is/are the source of the carbon cycle?

1. Carbon dioxide
2. Carbon
3. Carbonates
4. All of these

Q.

What are the ways by which carbon fixation takes place?

Q. The main role of bacteria in carbon cycle involves

1. Photosynthesis
2. Chemosynthesis
3. Fixation of atmospheric nitrogen
4. Breakdown of organic compounds

Q. Why is carbon called the basis for life on earth?

1. Carbon is inert and does not react with other elements
2. Carbon dioxide is abundant in the atmosphere
3. Carbon can form stable bonds with itself and other elements
4. Both b and c

Q.

What is happening to the amount of carbon dioxide in the atmosphere?

1. It is increasing

2. It is decreasing

3. It is holding steady

4. It is fluctuating wildly

Q. During the carbon cycle, which of the following carbon compounds would be utilized as an energy source by heterotrophs?

1. Carbon dioxide
2. Carbon monoxide
3. Carbonic acid
4. Organic molecules

Q. An internal shell is absent in

1. Octopus
2. Sepia
3. Loligo
4. Both B and C