Question

Rohan studied excretion in plants. He observed that the oxygen we breathe is actually a waste product of photosynthesis in plants. He wondered about other waste products and their uses. He was also bothered about the increased deforestation which disturbs the O₂-CO₂ balance of the environment. Read the above passage and answer the questions following. 

(i) How do plants release gaseous wastes from their body? 

(ii) Apart from oxygen, what other waste products are released by plants? Give two examples along with their use.

Answer 1

(i) Plants use different methods to perform excretion. They produce mainly two gaseous waste products, namely oxygen (produced during photosynthesis) and carbon dioxide (produced during respiration). The leaves of plants possess tiny pores called stomata and stems possess lenticels through which O₂ and CO₂ are diffused out of the plant body. 

(ii) Apart from oxygen, plants produce a number of waste products such as excess water, essential oils, aromatic oils, tannins, resins, gums, organic acids, latex, etc. Almost all of these products are useful to human. 

Gums and resins are used for varnishes and adhesives. Essential oils are used in cosmetics and soap making.