HOMEOSTASIS

 HOMEOSTASIS

“Maintenance of the internal conditions of body at equilibrium, despite changes in the external environment.”

•Human body remains at about 37°C

•The blood glucose level remains about 1g per liter.

•Osmoregulation: It is maintenance of the amounts of water and salts in body 

•Thermoregulation: The maintenance of internal body temperature is called thermoregulation.

•Excretion : the metabolic wastes are eliminated from body to maintain the internal conditions at equilibrium.

 HOMEOSTASIS IN PLANTS

•Plants respond to environmental changes and keep their internal conditions constant i.e. homeostasis. They apply different mechanisms for the homeostasis of water and other chemicals (oxygen, carbon dioxide, nitrogenous materials etc).

Removal of Extra Carbon dioxide and Oxygen

• It is removed from the tissue cells by diffusion. In leaves and young stems, carbon dioxide escapes out through stomata.

•In young roots, carbon dioxide diffuses through the general root surface, especially through root hairs.

Removal of Extra Water

•Plants store large amount of water in their cells for turgidity. Extra water is removed from plant body by transpiration.

•he appearance of drops of water on the tips or edges of leaves is called guttation

Removal of Extra Water

Removal of Other Metabolic Wastes

•Plants deposit many metabolic wastes in their bodies as harmless insoluble materials. For example, calcium oxalate is deposited in the form of crystals in the leaves and stems of many plants e.g. in tomato

•resins (by coniferous trees), gums (by keekar), latex (by rubber plant) and mucilage (by carnivorous plants and ladyfinger)

Osmotic Adjustments in Plants

•On the basis of the available amount of water and salts, plants are divided into three groups.

•Hydrophytes 

•Xerophytes 

•Halophytes 

Osmotic Adjustments in Plants