Question

In one year one hectare of a tropical rain forest will
(A) Consume 10 tonnes of $\mathop {CO}\nolimits_2$ and evolve 10 tonnes$\mathop O\nolimits_2$
(B) Consume 30 tonnes of $\mathop {CO}\nolimits_2$ and evolve 10 tonnes of $\mathop O\nolimits_2$.
(С) Consume 20 tonnes of $\mathop {CO}\nolimits_2$ and evolve 10 tonnes of $\mathop O\nolimits_2$
(D) Consume 40 tonnes $\mathop {CO}\nolimits_2$ and evolve 30 tonnes of $\mathop O\nolimits_2$

Answer 1

Tropical rain forests are called tropical evergreen forests. These thick forests are present within the regions near the equator and shut to the tropics. These regions are hot and receive heavy rainfall throughout the year.

Complete answer:
There's no particular time of year, the trees don't shed their leaves altogether. This can be the reason they're called evergreen.
The balance of oxygen and greenhouse emission is maintained by respiration and photosynthesis. The $\mathop {CO}\nolimits_2$ expelled by respiration is concerned by the plants for fixation by photosynthesis. The Amazon tropical rainforest has dense flora.
It's considered the lungs of our planet because it provides the essential environmental world service of continuously recycling greenhouse gas into oxygen; quite 20 percent of the globe's oxygen is produced within the Amazon rainforest.
One hectare (2.47 acres) may contain over 750 kinds of trees and 1500 species of higher plants. The quantity of oxygen that is produced by an acre of trees each and every year equals the number consumed by 18 people annually in a year.
One tree produces nearly 260 pounds of oxygen every year. One acre of trees removes up to 30 tonnes of $\mathop {CO}\nolimits_2$ every year.
These forests are rich in biodiversity and are present in equatorial and sub equatorial regions of central America, south America, parts of Africa and also Southeast Asia.

Hence our required option is b) that is Consume 30 tonnes of $\mathop {CO}\nolimits_2$ and evolve 10 tonnes of $\mathop O\nolimits_2$.

Note: Tropical rainforests are forests which are rich in biodiversity and consist of many species of plants and animals. They have 30-40 m tall trees and are covered under 4-5 stratas. The plants of these forests have buttress roots. They are characterised for maximum leaching.