- Certain lifelong activities conducted in our body are vital to our survival. These are life processes, for example nutrition, circulation, respiration and excretion.
- Energy is primarily needed for all the above processes and all plants and animals are directly or indirectly dependent on the sun for it.
- Green plants can photosynthesise and are autotrophs whereas non-green plants and animals are heterotrophs. They may be saprophytes or parasites.
- The animal kingdom, unlike plants, has nutrition modes that are holozoic and involve ingestion, digestion, absorption, assimilation and egestion. Various animals have varied modes of processing food.
- Plants photosynthesise and need sunlight, carbon dioxide, water and chlorophyll to prepare food. Oxygen and water are the by-products.
- Activities to demonstrate the importance of chlorophyll, carbon dioxide and sunlight in the process of photosynthesis.
- Nutrition in Amoeba, Paramoecium and Human beings.
- Respiration is external (breathing), taking oxygen in and producing carbon dioxide and internal (intracellular production of energy) and takes place in the mitochondria, the 'powerhouse of the cell'.
- Aerobic respiration takes place using oxygen and resulting in the production of carbon dioxide and water and 36 ATP of energy, whereas anaerobic respiration occurs in bacteria in the absence of oxygen and the end products are ethyl alcohol and carbon dioxide and only 2 ATP of energy.
- All multicellular animals have a transport system.
- The transport system generally includes a circulating fluid, tubes / pipes that transport it and a pump that propel it through out the body.
- Upward movement of water from roots to leaves is known as the ascent of sap.
- Effect of root pressure in the transport of water.
- The complex tissue responsible for movement of water in plants is xylem and for food is phloem..
- Water moves through root hair, cortex, endodermis, pericycle, into the xylem of vascular bundle.
- The loss of water in the form of water vapour from exposed parts of plants is called transpiration. This exerts a suction pull that maintains the upward flow of water in the plant.
- Organic matter, sugars, metabolites, hormones are translocated through Phloem.
- Functions of the circulatory system in animals is Transport of nutrients Transport of nitrogenous wastes Transport of respiratory gases Transport of hormones and intermediate metabolites Transport of heat, water and chemical substances Protection against diseases.
- Blood - Fluid Connective Tissue made up of plasma and blood corpuscles (RBC, WBC, blood platelets).
- Clotting of Blood : Within the body of humans there is an inbuilt mechanism that prevents the excessive loss of blood when a part of the body is injured. Nature has provided the body with an insurance against excessive blood loss. This insurance is blood clotting. Blood clotting is also called as blood coagulation.
- Mammalian heart : It is a four chambered heart, consisting of two auricles and two ventricles.
- Circulation in human is called double circulation as blood moves through heart twice.
- Functions of lymph : Provides defense against pathogens. It carries fats and lipids from the small intestine to the blood. Plasma protein macromolecules diffuse into the lymph vessels, so they come to blood through the lymph.
- Excretory organs in man include lungs, kidneys, liver and skin.
- Kidneys are the major organs of excretion.
- Kidneys contain about two million functional units called nephrons.
- Excretion of oxygen, water and carbon dioxide from plants. Other waste includes dead cells,dry leaves, resins and gums.
|
