(i) Since ventricles have to pump blood into various organs, they have thicker muscular walls than atria do.
(ii) The lining of alimentary canal has muscles that contract rhythmically in order to push the food forward. These are peristaltic movements.
(iii) In desert plant, stomata open at night and absorb CO2, and store it as an intermediate compound, that is converted into carbohydrates during daytime.
