Excretion in plants and Humans

2.67a Recall the origin of carbon dioxide and oxygen as waste products of metabolism and their loss from the stomata of a leaf.

1. Photosynthesis = Co2 + H2O ---> C6H12O6 + O2 (the oxygen is an example of excretion


2. Respiration = C6H12O6 + O2 ---> ATP + CO2 + H2O (The carbon dioxide is given off by the plant as a waste. Another form of excretion).

2.67b Recall that the lungs, kidneys and skin are organs of excretion

1. The lungs excrete Carbon dioxide waste from respiration.

2.The kidneys excrete excess water, Urea (Nitrogen waste from amino acids) and Salts


3. The Skins excretes water and salts (Sweating) and a little bit of Urea (Not much)

The Excretion comes out through the sweat gland