10th Science Life Processes Notes PDF

CHAPTER – 6 LIFE PROCESSES All living things perform certain life processes like growth, excretion, respiration, circulation etc. All the processes like respiration, digestion, which together keep the living organisms alive and perform the job of body maintenance are calle...

CHAPTER – 6 LIFE PROCESSES All living things perform certain life processes like growth, excretion, respiration, circulation etc. All the processes like respiration, digestion, which together keep the living organisms alive and perform the job of body maintenance are called life processes. Examples : Kinds of nutrition in which in organic Kinds of nutrition in which in organisms do materials like CO2, water etc are utilized to not possess the ability to synthesize their prepare organic food by the process of own food. They depend on autotrophs for photosyntheses their food supply directly or indirectly. Eg. Green Plants eg. Animals, Fungi 50 X – Science AK Autotrophic Nutrition : The organisms which carry out autotrophic nutrition are called autotrophs (green plants) Autotrophic nutrition is fulfilled by the process by which autotrophs take in CO2 and H2O and convert these into carlohydrates in the presence of chlorophyll, sunlight is called PHOTOSYNTHESIS Equation : Raw Materials for Photosynthesis : q Sunlight q Chlorophyl Sunlight absorbed by chlorophyll q CO2 enters through Stomata, and Oxygen (O2) is released as by product through stomata on leaf. q Water water + dissolved minerals like Nitrogen phosphorous etc are taken up by the roots from the soil. Site of Photosynthesis : Chloroplast in the leaf. Chloroplast contain chlorophyll. (green pigment) Main Events of Photosynthesis : q Absorption of light energy by chlorophyll q Conversion of light energy into chemical energy + splitting (breaking) of water into hydrogen and oxygen. q Reduction of CO2 to carbohydrates. STOMATA : Tiny pores present on the surface of the leaves FUNCTIONS : (i) Exchange of gases O2/CO2 (ii) Loses large amount of water [water vapour] during transpiration. 51 X – Science AK How do organisms obtain their food Unicellular / single celled organism : food is taken up through entire surface. Example : (i) Amoeba. (ii) Paramaecium 52 X – Science AK  NUTRITION IN HUMAN BEINGS The human digestive system comprises of alimentary canal and associated disgestive glands. Mouth Intake of whole food  Teeth Chewing/grinding of food.  Tongue Rolling of food  + Tasting of food + Swallowing / pushing down of the food Salivary Glands Secrete Saliva + Mucus. Salivary  →  Starch amylase Sugar [Saliva] Oesophagus Taking food from mouth to stomach by  Peristaltic movements [contraction and expansion of muscles of the oesophagus] Stomach Gastric glands secrete Gastric juice 53 X – Science AK Small Intestinal Small Intestine Villi → helps in absorption of food into the blood. [finger like projections] small intestine Receives secretion from Emulsification : The process of breakdown of large fat globules into smaller fat globules by bile juice. Large intestine Absorb excess of water. The rest of the material is removed from the body via the anus. (Egestion) 54 X – Science AK  Respiration Respiration involves (i) Gaseous exchange : Intake of oxygen from the atmosphere and release of CO2 → Breathing (ii) Breakdown of simple food in order to release energy inside the cell → Cellular Respiration Breakdown of Glucose by various pathways * Takes place in the presence of * Takes place in the absence of oxygen oxygen * Occurs in mitochondria * Occurs in cytoplasm * End products are CO2 and H2O * End products are alcohol or lactic * More amount of energy is released acid. * Less amount of energy is released. 55 X – Science AK  Human Respiratory System Passage of air through the respiratory system. Nostril  Nasal Passage  Nasal Cavity  Pharynx  Larynx  Trachea  Bronchi  Lungs  Bronchioles  Alveolar → Blood capillaries * During inhalation the thoracic * Thoracic cavity contracts cavity (chest cavity) expands * Ribs move downwards * Ribs lift up Diaphragm becomes dome shaped * Diaphragm become flat in shape * Volume of lungs decreases and air * Volume of lungs increases and air exits from the lungs. enters the lungs 56 X – Science AK Exchange of Gases between alveolus, blood and tissues. Terrestial Organism – use atmospheric oxygen for respiration Aquatic Organisms – used dissolved oxygen for respiration Respiration in Plants : Respiration in plants is simpler than the respiration in animals. Gaseous exchange occur through 1. Stomata in leaves 2. Lenticels in stems 3. General surface of the roots. 57 X – Science AK  Life Process (II) Transporation and Excretion – Human beings like other multicellular organism need regular supply of food, oxygen etc., This function is performed by circulatory system or Transport system. – The circulatory system in human beings consists of : The circulatory system in human beings consists of : A Pumping Organ Blood vessels A circulatory medium Heart - Arteries & Veins Blood & Lymph Deoxygenate Vena Right Right Right Blood Cava Atrium Atrium Ventricle (from body) (Relaxed) (contracts) (relaxed) Body Parts Right Blood Circulation ventricle in Human Heart contracts via AoRTA Lungs Left Left Left Left Oxygenated Ventricle Ventricle Atrium Atrium blood (contracts) (relaxed) (contracts) (relaxed) AORTA 58 X-Science  Blood (A fluid Connective Tissue) Solid Component Liquid Component Blood Corpuscles PLASMA R.B.C.s Blood W.B.C. A yellow colour fluid Platelets Provide Body contain 90% water & - carries respect helps in defence by 10% Organic substances gas (O2, CO2) Blood engulfing the like - contain Hb Clotting germ cells & - Plasma Proteins viz. impart red colour producing albumin, globulin to me blood antibodies inorganic-mineral ions - Lymph - a yellowish fluids escapes from the blood capillaries into the intercellular spaces contain less proteins than blood. Lymph flows from the tissues to the heart assisting in transportation and destroying germs. Blood Vessels Arteries Veins 1. Carry Oxygenated blood from 1. Carry deoxygenated blood heart to body part except from body parts to heart pulmonary Artery except pulmonary vein. 2. Also called distributing Vessel 2. Also called collecting Vessel. 3. Thick and elastic 3. Thin and Less elastic. Transportation in Plants - There are two main conducting Pathways in a Plant Xylem Phloem 1. Carries water & minerals 1. Carries product of from the roots to other part photosynthesis from leaves of the plant to the other part of the plant. 2. No energy is used. 2. Energy is used from ATP 59 X-Science – Transpiration is the process of loss of water as vapour from aerial parts of the plant. Function : 1. Absorption and upward movement of water and minerals by creating PULL. 2. helps in temperature regulation in Plant. – Transport of food from leaves (food factory) to different part of the plant is called Translocation. EXCRETION – The process of the removal of the harmful metabolic wastes from the body. – Excretory system of human beings includes : 1) A pair of kidneys ii) A Urinary Bladder iii) A pair of Ureter iv) A Urethera – Urine produced in the kidneys passes through the ureters into the urinary bladder where it is stored until it is released through the urethera. – The purpose of making urine is to filter out waste product from the blood ie, urea which is produced in the liver. – Each kidney has large numbers of filtration units called nephrons. – The Urine formation involves three steps 1. Glomerular Filtration : Nitrogenous wastes, glucose water, amino acid filter from the blood into Bowman Capsule of the nephron. 2. Tubular reabsorption : Now, useful substances from the filtrate are reabsorbed back by capillaries surrounding the nephron. 3. Secretion Extra, water, salts are secreted into the tubule which open up into the collecting duct & then into the ureter. 60 X-Science – Haemodialysis : The process of purifying blood by an artificial kidney. it is meant for Kidney failure patient. Excretion in Plants Through stomata – Oxygen, CO2 & H2O (Transpiration) – Other wastes may be stored in leaves, bark etc. which fall off from the plant. – Plants excrete some waste into the soil around them. – Gums, Resin fi In old Xylem – Some metabolic wastes in the form of crystals of Calcium oxalates in the leaves of colocasia and stem of Zamikand. Life Processes EXERCISE (Question Bank) Very Short Answers (1 Mark) 1. State one difference between autotrophic and heterotrophic mode of nutrition. 2. What will happen to a plant if the xylem is removed. 3. What is the role of saliva in the digestion of food? 4. Name the tissue that transports water and minerals in plants. 5. What is the role of acid in our stomach? 6. What is emulsification 7. Name the organelle in which photosynthesis occur. 8. Name the largest artery in the human body. 9. Define transpiration 10. What are structural and functional unit of kidneys called. Short Answers (2 Marks or 3 Marks) 1. How is small intestine designed to absorb digested food? 2. What are stomata? Draw a labelled diagram of stomata. 61 X-Science 3. Write the equation for the process of breakdown of glucose in a cell i) in the presence of oxygen ii) in the absence of oxygen. 4. Write the difference between inhalation and exhalation. 5. List the three events which occur during photo synthesis. 6. How does transpiration helps in upward transport of substances. 7. Describe the process of double circulation in human beings. 8. Write the functions of the components of blood. Long Answers (5 Marks) 1. Explain the process of digestion of food in mouth stomach and small intestine in human body. Draw a well labelled diagram. 2. Draw a diagram showing Human Respiratory system. Label the following parts i) Larynx ii) Trachea iii) Bronchus iv) Lungs 62 X-Science