Synopsis

   H    Movement of various types can be taken as an indication of life.

  H   Maintenance of life requires processes like nutrition, respiration, transport of materials within the body and excretion of waste products.

   H   Autotrophic nutrition involves the intake of simple inorganic materials from the environment and using an external energy source like the Sun to synthesise complex high energy organic material.

   H   Heterotrophic nutrition involves the intake of complex material prepared by other organisms.

   H   In human beings, the food is eaten is broken down by various steps along the alimentary canal and the digested food is absorbed in the small intestine to be sent to all cells in the body.

   H   During the process of respiration, organic compounds such as glucose are broken down to provide energy in the form of ATP. ATP is used to provide energy for other reactions in the cell.

   H   Respiration may be aerobic or anaerobic. Aerobic respiration makes more energy available to the organism.

  H   In human beings, the transport of materials such as oxygen, carbon dioxide, food and excretory product is a function of the circulatory system. The circulatory system consists of the heart, blood and blood vessels.

   H   In highly differentiated plants, transport of water, minerals, food and other materials is a function of the vascular tissue which comprises of xylem and phloem.

   H   In human beings, excretory products in the form of soluble nitrogen compounds are removed by the nephrons in the kidneys.

   H   Plants use a variety of techniques to get rid of waste material. For examle, waste material may be stored in the cell - vacuoles or as gum and resin, removed in the falling leaves, or excreted into the surrounding soil.

   H   The processes which together perform this maintenance job are life processes.

   H   Energy is needed to maintain a state of order in our body.

   H   Carbon and energy requirements of the autotrophic organism are fulfilled by photosynthesis.

   H   6CO2 + 12H2O  C6H12O6 + 6O2 + 6H2O

                                                   (Glucose)

   H   The events occur during the process –

          i)   Absorption of light energy by chlorophyll.

          ii)  Conversion of light energy to chemical energy and splitting water molecules into hydrogen and oxygen.

          iii) Reduction of carbondioxide to carbohydrates.

   H   Massive amounts of gaseous exchange takes place in the leaves through these stomata.

   H   The saliva contains an enzyme called salivary amylase that breaks down starch which is a complex molecule to give simple sugar.

   H   Gastric gland release hydrochloric acid, a protein digesting enzyme called pepsin and mucus.

   H   Herbivores eating grass need a longer smell intestine to allow the cellulose to be digested.

   H   Meat is easier to digest, hence carnivores like tigers have a shorter small intestine.

   H   Trypsin digestes proteins, lipase breaks down the fats.

   H   The inner lining of the small intestine has numerous finger like projections called Villi which increase the surface area for absorption.

   H   In the respiration, the first step is the break down of glucose, a six - carbon molecule, into a three - carbon molecule called pyruvate. This process takes place in cytoplasm.

   H   If respiration occurs in the presence of oxygen it is called Aerobic respiration.

   H   If respiration occurs in the absence of oxygen, it is called Anaerobic respiration.

   H   When there is a lack of oxygen in our muscle cells, the pyruvate converted into lactic acid. This causes cramps.

   H   ATP is the energy currency for most cellular processess.

   H   Plants exchange gases through stomata.

   H   Lungs are spongy and elastic structures helps in respiration.

   H   If the Alveolar surface were spread out, it would cover about 80 m2.

   H   Oxygen is carried by the Red blood corpuscles.

   H   The heart is a muscular organ which is as big as our fist.

   H   Valves ensure that blood does not flow backwards when the atria or ventricles contract.

   H   Amphibians or many reptiles have three chambered hearts.

   H   Fishes have only two chambered heart.

   H   If blood goes through the heart twice during each cycle is called double circulation.

   H   If blood goes through the heart once during one cycle of the passage through circulation is called single circulation.

   H   The normal systolic pressure is about 120 mm of Hg and diastolic pressure is 80 mm of Hg.

   H   Blood pressure is measured with an instrument called sphygmomanometer.

   H   High blood pressure is also called hypertension.

   H   Arteries are the vessels which carry blood away from the heart to various organs of the body.

   H   Veins collect the blood from different organs and bring it back to the heart.

   H   The smallest vessels have walls which are one cell thick and are called capillaries.

   H   Platelet cells plug the leaks by helping the blood to clot.

   H   Lymph is similar to the plasma of blood but colourless and contains less protein.

   H   Lymph carries digested and absorbed fat from intestine and drains excess fluid from extra cellular space back into the blood.

   H   The xylem moves water and minerals obtained from the soil.

   H   The phloem transports the products of photosynthesis from the leaves where they are synthesised to other parts the plant.

   H   Transpiration helps in the absorption and upward movement of water and minerals dissolved in it from roots to the leaves.

   H   The effect of root pressure in transport of water is more important at night.

   H   The transport of soluble products of photosynthesis is called translocation and it occurs in the part of the vascular tissue known as phloem.

   H   The biological process involved in the removal of these harmful metabolic wastes from the body is called excretion.

   H   The excretory system of human beings includes a pair of kidneys, a pair of ureters, a urinary bladder and a urethra.

   H   Kidneys are located in the abdomen, one on either side of the back bone.

   H   Urine produces in the kidneys passes through the ureters into the urinary bladder where it is stored until it is released through the urethra.

   H   An artificial kidney is a device to remove nitrogenous waste products from the blood through dialysis.

   H   Normally, in a healthy adult, the initial filtrate in the kidneys about 180 L daily.

   H   Many plant waste products are stored in cellular vacuoles.

   H   Waste products may be stored in leaves that fall off.

   H   Other waste products are stored as resins and gums, especially in old xylem.

   H   Plants also excrete some waste substances into the soil around them.

   H   Organ donation is a generous acts of donating an organ to a person who suffers from non - function of organs.

   H   Common transplantations include cornea, kidneys, heart, liver, pancreas, lungs, intestines and bone marrow etc. occur just after the donor has died or when the doctor declares a person brain dead.

  H    Some organs, such as kidney, part of a liver, lung etc., and tissues can be donated while the donor is alive.