How is excretion in plants useful to human beings?

Excretion in plants results in the production of various by-products. While these substances may be considered waste for the plant, many of them are highly useful to humans. Examples include:

• Oxygen: Released as a by-product of photosynthesis, it is essential for the survival of humans and other organisms on Earth.
• Tannins: Stored mainly in leaves and bark, tannins are plant waste products that are widely used in the preparation of tea.
• Leaf and bark shed: Plants often store waste in leaves and bark, which are shed periodically. These shed parts decompose and are useful in making manure.
• Essential oils: Stored in leaves, these oils are considered plant excretory products but serve multiple purposes for humans, including medicinal and aromatic uses.
• Gums: Plant excretory products that are widely used in the production of adhesives.
• Resins: Useful in making varnishes, glazing agents, and other industrial products.
• Natural rubber: Obtained from the rubber plant, it is an important raw material in the tyre and rubber industry.

Note

Metabolism in the cells of living organisms produces both useful and toxic by-products. To maintain balance, organisms eliminate these metabolic wastes through a process known as excretion.