Life Processes: Nutrition, Respiration, Transport, Excretion

Chapter 6. Life processes Life processes(Question : What are life processes? OR What process would you consider essential for maintaining life?) Life processes are the basic process in living organisms which are necessary for the maintaining life. The basic life processes are;...

Chapter 6. Life processes Life processes(Question : What are life processes? OR What process would you consider essential for maintaining life?) Life processes are the basic process in living organisms which are necessary for the maintaining life. The basic life processes are; a) Nutrition b) Respiration c) Transportation d) Excretion Nutrition Nutrition is the process of in taking in of food by an organism and its utilization by the body to get energy for growth, for body building, for repairing the damaged parts of the body. Modes of Nutrition (Question: Explain the different mode of nutrition) There are two modes of nutrition. They are autotropic nutrition and heterotrophic nutrition. 1. Autotropic nutrition Autotropic nutrition is the mode of nutrition in which organisms prepare their own food is synthesized from simple inorganic raw materials such as carbon dioxide and water. Eg; All green plants 2. Heterotrophic nutrition Heterotrophic nutrition is the mode of nutrition in which organisms get food directly or indirectly from autotrophs Eg: All animals and fungi have this type of nutrition Types of heterotrophic nutrition (QUESTION: Briefly explain the different types of heterotrophic nutrition.) a) Saprophytic nutrition: is the nutrition in which organisms get their food from dead and decaying organisms. They break down the food materials outside their body and then absorb it. Eg; mushroom. Yeast, bread mould b) Parasitic nutrition: is the nutrition in which organisms get their food from the living organisms (host) without killing them. Eg; leech, lice, tape worm round worm c) Holozoic nutrition: is nutrition in which organisms take food directly and then digests and absorbs it. Eg; amoeba, paramecium, birds, humans etc. QUESTION: What are the differences between autotropic nutrition and heterotrophic nutrition? Autotropic nutrition Heterotropic nutrition Food is synthesized from simple Food is obtained directly or inorganic raw materials such as indirectly from autotrophs. carbon dioxide and water Chlorophyll is required Chlorophyll is not required Food is generally prepared during Food can be obtained at all time day time All green plants and some bacteria All animals and fungi have this have this type of nutrition type of nutrition Nutrition in Plants (QUESTION: Define photosynthesis. Write the equation) Photosynthesis: is the process by which green plants containing chlorophyll prepare their own food by using CO2 and water, in the presence of sunlight. The food prepared is carbohydrate and stored in the form of starch. Oxygen is released during this process. Equation Photosynthesis sunlight 6CO2 + 12 H2O ------------------------- C6H12O6 + 6H2O + 6O2 chlorophyll  QUESTION: Where do plants get each of the raw materials required for photosynthesis? The following raw materials are required for photosynthesis Water: Plants absorb water from soil through roots and transport to leaves. Water enters the root hairs by osmosis process Carbon dioxide: Plants get CO2 from atmosphere through stomata by diffusion. Sunlight: Sunlight is absorbed by chlorophyll. Processes of Photosynthesis (QUESTION: Explain the three steps of photosynthesis) Photosynthesis takes place in three steps. They are; a) Absorption of light energy by chlorophyll b) Conversion of light energy into chemical energy and splitting of water molecule into hydrogen and oxygen. c) Reduction of carbon dioxide by hydrogen to form of carbohydrates. Chlorophyll: are the green pigments present in the leaves. If we observe a cross section of a leaf under microscope, we can see cells containing green dot like structures called chloroplast, which contain chlorophyll. Stomata: are tiny pores present in the leaves through which exchange of gases takes place. Each stoma is surrounded by guard cells, which help in the opening and closing of stomata. Function of stomata i) Stomata help in gas exchange ii) Transpiration also occurs through transpiration Function of Guard cells It helps in opening and closing of stomata. Opening and closing of stomata Opening and closing of stomata is controlled by guard cells. Photosynthesis takes place in guard cells as it contains chloroplast. When water enters the guard cells for photosynthesis during the day time, it swells and outer thin wall bulges out resulting in opening of stoma. When the guard cells lose water during night as there is no photosynthesis, it shrinks and thick inner wall of guard cells straightens resulting in closing of stoma. (QUESTION: How do stomata open and close?. In desert plants, stomata open during night time and close during day time to prevent excessive loss of water through transpiration. Therefore, CO2 enters through stomata at night and get stored. this stored CO2 is used for photosynthesis during day time.  QUESTION: What are the necessary conditions for autotropic nutrition and what are its byproducts? Autotropic nutrition takes place through the process of photosynthesis. CO2, water, chlorophyll, and sunlight are the necessary conditions required for autotropic nutrition. Water and oxygen are the byproducts of photosynthesis. ( What happens if the leaves are coated with Vaseline?) THINK Starch Test (Iodine Test) i) Boil the leaf to kill the plant cells ii) Boil the leaf in ethyl alcohol in water bath to remove chlorophyll. iii) Put the leaf in hot water to make it soft. iv) Add one or two drops iodine solution. v) If it turns into blue-black colour, shows the presence of starch. If it remains brown, shows the absence of starch. I. Expt: 1. Chlorophyll is necessary for photosynthesis 1. Take a potted plant with variegated leaves. 2. Place it in the dark room for 24 to 48 hours in the dark room to remove the starch (Destarching) 3. Place it in the sunlight for few hours. 4. Do starch test with iodine solution (Write Starch test steps) Observation Green part of leaves turns blue black shows the presence of starch. Non-green part of leaves remains brown shows the absence of starch Variegated leaf: The leaf with green and non-green area. Eg: Croton, Money Plant  Expt: 2. Sunlight is necessasary for photosynthesis 1. Take a potted plant. 2. Place it in the dark room for 24 to 48 hours in the dark room to remove the starch (Detaching) 3. Cover a part of leaf with black paper or black cloth.to block the light 4. Place it in the sunlight for few hours. 5. Do starch test 6. (Write Starch test steps) Observation Uncovered part of leaves turns blue black shows the presence of starch. Covered part of leaves remains brown shows the absence of starch Expt: 3. Carbon di oxide is necessary for photosynthesis i) Take a potted plant. ii) Place it in the dark room for 24 to 48 hours in the dark room to remove the starch (Detaching) iii) Insert a part of leaf in the conical flask containing KOH. (KOH absorbs CO2) And make it air tight. iv) Place the set-up in sunlight for few hours. v) Do starch test with iodine solution. (Write Starch test steps) Observation The part of leaf inside the conical flask remains brown shows the absence of starch. (Photosynthesis didn’t take place as there was no CO2). The part of leaf which was outside turs into blue black shows the presence of starch. Nitrogen is essential for the synthesis of protein. Plants get nitrogen from the soil in the form of nitrates or nitrites. Amoeba shows holozoic nutrition. Nutrition in human beings Nutrition in human beings takes place in digestive system. It consists of alimentary canal and digestive glands, which produce digestive enzymes. The digestive system consists of mouth, esophagus, stomach, small intestine, large intestine and anus. The digestive glands are salivary glands, liver, gastric glands, pancreas and intestinal glands. QUESTION :( Explain the digestion of food in mouth, stomach, duodenum and small intestine) In the Mouth: The food is broken down into smaller particles by the teeth and mixed with saliva from the salivary glands. Saliva contains the enzyme, salivary amylase, which converts starch into maltose sugar. Then the food is passed to esophagus and then to stomach. Esophagus (Food pipe) : It is the tube that conducts food from pharynx to stomach. Due to peristaltic movements food is pushed forward. Peristalsis: The alternative contraction and expansion of muscles in alimentary canal that helps to push the food forward is called peristalsis. In the Stomach: The gastric glands in the stomach produces gastric juices which contains the enzyme pepsin, hydrochloric acid and mucus. Pepsin breaks down protein into peptides. The HCl present in our stomach creates an acidic medium. In this acidic medium, the inactive enzyme pepsinogen is converted into active pepsin, which is a protein digesting enzyme. It also kills the germs that enter along with the food. (QUESTION: What is the role of acid in our stomach? Mucus protects the wall of stomach from the action of acid. Then the food is passed into small intestine. In the duodenum (the upperpart of small intestine) : The food is mixed with bile from liver and pancreatic juice from pancreas. Bile breaks down fats into smaller globules. (Emulsification: The process of breaking down of large fat globules into small globules) Gall bladder: It stores bile temporarily. Pancreatic juice contains enzymes like trypsin and lipase. Trypsin breakdown proteins into amino acids and lipase breaks down fat into fatty acid and glycerol. In the small intestine: The intestinal glands in the wall of small intestine produces intestinal juice. The enzymes of intestinal juice convert carbohydrates into glucose, fats into fatty acids and glycerol, and proteins into amino acids. Villi The wall of small intestine has several finger-like projections called villi, having blood vessels. It increases the surface area for the absorption of digested food. The villi absorb the digested food and then it is transported to all the cells through blood. The undigested food is passed to large intestine. In the large intestine: Water is absorbed and the waste materials (faeces) is removed through the anus. QUESTION: How are fats digested in our body? Where does this process take place? Fats are present in the form of large globules in the small intestine. The small intestine receives the secretions from the liver and the pancreas. The bile salts in the bile breakdown the large fat globules in to tiny droplets so that lipase enzyme in pancreatic juice can easily digest the fat. This process is called emulsification of fats. This process take place in small intestine. QUESTION: What is the function of digestive enzyme? Digestive enzymes like amylase, pepsin, trypsin, lipase etc. helps in the breaking down of complex food particles into simple ones. These simple molecules can be easily absorbed by the blood and thus transported to all the cells of the body. QUESTION: What is the role saliva in the digestion of food? Saliva is secreted by salivary glands in the oral cavity. It moistens the food for easy swallowing. It contains a digestive enzyme called salivary amylase, which break down starch into maltose sugar. QUESTION: How is the small intestine designed to absorb digested food? The small intestine has millions of tiny fingers like projections called villi. These villi increase the surface area for efficient food absorption. Inside the villi, many blood vessels are present that absorb the digested food and carry to blood stream. Blood transport the absorbed food in to all the cells of the body. QUESTION: Why is diffusion insufficient to meet the oxygen to meet the requirements of multicellular organisms like humans? Multicellular organisms like humans possess a complex body design. They have specialized cells and tissues for performing various necessary functions of the body such as intake of oxygen and food. Unlike unicellular organisms, multicellular cells are not in direct contact with the outside environment. Therefore, diffusion cannot meet their oxygen requirements.  Respiration Respiration is the processes of breaking down of glucose by using oxygen to release energy to carry out life process. The energy released during respiration is used to make ATP (Adenosine Triphosphate) from ADP (Adenosine Diphosphate) and inorganic phosphate. ADP + Phosphate ---------------- ATP Energy is stored in the cells in the form of ATP. When the cells need energy, ATP is broken down in the presence of water to form ADP and energy is released. Therefore, ATP is the Energy currency of the cell. ATP -------------- ADP + Energy Aerobic respiration in Mitochondria In aerobic respiration, glucose is converted into pyruvate in the cytoplasm in the presence of oxygen(GLYCOLYSIS). Then in the presence of oxygen, pyruvate is converted into CO2, Water and energy, in mitochondria(KREB CYCLE). C H O + 6O ₂ ------------- 6CO₂ + 6H₂O + 38 ATP (Energy) 6 12 6 Anaerobic respiration in yeast In anaerobic respiration in yeast, glucose is converted into pyruvate and in the absence of oxygen pyruvate is converted into ethanol, carbon dioxide and energy. This process is also called fermentation. Anaerobic respiration in muscle cells and muscle cramp When there is lack of oxygen, especially during vigorous activities, in our muscles, pyruvate is converted into lactic acid. Due to the accumulation of lactic acid in muscles cause muscle cramps. Oxidation of glucose in three different ways. Ques: What are the differences between aerobic and anaerobic respiration? Aerobic respiration Anaerobic respiration It occurs in the presence of oxygen It occurs in the absence of oxygen It occurs in cytoplasm and mitochondria It occurs only in cytoplasm End products are CO2 and water End products are ethanol or lactic acid More energy is released (38 ATP) Less energy is released (2ATP) Gas Exchange in lower animals In lower animals, which live in water like amoeba, chlamydomonas exchange of gases takes place through the surface of cells by diffusion. Gas Exchange in Higher plants. In higher plants, exchange of gases takes place through stomata, lenticels and surface of roots by diffusion. Individual cell get air from intercellular space. Respiratory Organs in Animals Animals have well developed organs for breathing. The respiratory organs in ; Human beings – Lungs, Fish – Gills, Frog – Lungs and Skin Insects – spiracles and trachea Ques: Aquatic animals have faster rate of breathing than terrestrial animals. why? Terrestrial animals take up oxygen from the atmosphere, whereas aquatic animals need to utilize oxygen dissolved in the water.. Air contains more oxygen when compare to water. Since the amount of oxygen is high in the air, the terrestrial animals do not have to breath faster to get enough oxygen. But the amount of oxygen dissolved in water is very less. Therefore, aquatic animals have faster rate of breathing than terrestrial animals Human respiratory system The human respiratory system involves the nostrils, nasal cavities, pharynx, larynx, trachea(windpipe), bronchi, bronchioles, alveoli and lungs External nostrils → Nasal cavity →Pharynx → Larynx → Trachea→ Bronchi → Bronchioles →Alveoli Nostrils * There are two nostrils through which air enters the lungs. * The hairs in the nostrils trap the dust particles and prevent them entering the lungs. Nasal Passages (Nasal Cavities)  It is lined by mucus membrane. Mucus traps the dust particles. Moreover, it humidifies and warms the air when it passes through nasal passage. Pharynx  It is the common junction for air and food.  Epiglottis is the flap like structure present at the entrance of trachea.  Epiglottis closes the trachea during swallowing and prevents the entry of food to trachea. Laryn x Commonly called as Adam’s apple. (Voice box)  It consists of vocal cords.  It produces sound, when the vocal cords vibrate. Trachea (Wind Pipe)  It is the tube that conducts air.  It is covered with C-shaped cartilaginous rings to prevent trachea from collapsing, when there is less air in trachea. Bronchi (Bronchus) In the chest cavity, the trachea divides into two branches called bronchi.  Each bronchus enters lungs Bronchioles  In the lungs the bronchus again divides to form finer branches called bronchioles. Alveoli (Air Sacs) Alveoli are the structural and functional units of lungs. The balloon like structures present at the end of each bronchiole is called alveoli. Function of Alveoli (Alveolus) : Alveoli help in gas exchange. Lungs They are spongy, elastic bags. It is covered by two membranes called pleura Que: How are the lungs designed in human beings to maximize the area for exchange of gases?  Each lung contains 300 -350 millions of alveoli. These alveoli increase the surface area for gas exchange making the process of respiration more efficient. Each alveolus is surrounded by capillaries. Capillaries have thin walls Breathing Mechanism Breathing movements consists of Inhalation (Inspiration) and Exhalation (Expiration).  Breathing movements are controlled by diaphragm and intercostal muscles of ribs. Haemoglobin Haemoglobin is the respiratory pigment present in RBCs to transport oxygen, which has high affinity for O2. Ques: What would be the consequences of deficiency of heamoglobin in your body? The deficiency of haemoglobin in our body leads to anemia. The blood is unable to carry the sufficient amount of oxygen required by the body and less energy only available to the body. As a result, person becomes weak, pale and lethargic. QUE: How is o2 and co2 transported in human beings? Oxygen is transported by the respiratory pigment, haemoglobin as oxyhaemoglobin. CO2 is transported mainly in dissolved form and partially by haemoglobin as carbaminohaemoglobin. Residual air: During breathing cycle lungs do not exhale air completely. Even after the forcible exhalation some amount of air is left behind the alveolus. This air is called residual air. Due to residual air, exchanging of gases continuously takes place in alveolus. Transportation in animals Human transport system consists of heart, blood and blood vessels. Blood (fluid connective tissue) Blood Consists of plasma and blood cells. Functions of Blood Blood transports; - oxygen from the lungs to body parts - CO2 from body parts to lungs - digested food from intestine to all cells - regulate body temperature - maintain water balance Plasma Plasma transports food, CO2 and nitrogenous wastes Blood Cells Three types of blood cells. 1. Red blood cells (erythrocytes)- oxygen is carried by hemoglobin in red blood cells 2. White blood cells (leucocytes)- helps in defense mechanism 3.Platelets – helps in blood clotting (QUESTION: What are the components of transport system in human beings? What are the functions of these components?) The main components of transport system in the human beings are heart, blood and blood vessels. Heart pumps blood. Blood helps in the transport of oxygen, CO2, nutrients and waste materials. Blood vessels (arteries, veins and capillaries) carry blood either from the body parts to heart or from the heart to body parts. Human Heart CHAMBERS IN HEART Two upper chambers of heart are called Atria (Atrium-sing.) Two lower chambers of heart are called Ventricles. Therefore, Human heart is divided into four chambers – right atrium, right ventricle, left atrium, and left ventricle. Left ventricle wall is thicker than wall of other chambers of heart. Give reason.  Wall of Left ventricle is thicker than right ventricle as it has to pump the blood to distant part of the body. Function of heart valves Valves present in the human heart prevent the backward flow of blood. It allows flow of blood only in one direction. QUESTION: Why is it necessary to separate oxygenated and deoxygenated blood in mammals and birds? The separation of right side and left side of the heart is useful to prevent the mixing of oxygenated and deoxygenated blood. Such separation allows a highly efficient supply of oxygen to the body. This is useful in warm blooded animals like birds and mammals. they need large amount of oxygen to get high energy to maintain body temperature. Flow of blood in human heart Pulmonary veins bring oxygenated blood from lungs to left atrium When the left atrium contracts, blood flows to left ventricle When the left ventricle is contracted, blood is pumped to body parts Venacava brings deoxygenated blood to right atrium. When it contracts blood flows to right ventricle Pulmonary artery deoxygenated blood from right ventricle to lungs for oxygenation. Double circulation Blood flows through the heart twice in one circulation. Once between heart and lungs and other between heart and body parts. Pulmonary circulation – The blood circulation between heart and lungs. Systemic circulation – The blood circulation between heart and body parts. Therefore, blood circulation in human heart is called double circulation.  Number of heart chambers in Fish, Amphibians and Reptiles. Amphibians & reptiles- have 3 chambered heart where little mixing of Oxygenated blood & Deoxygenated blood takes place. Therefore, their body temperature varies with the temperature of the environment. (cold blooded animals) Fishes have two chambered heart. Amphibians and reptiles have three chambered heart except crocodile which possess 4 chambered heart. Birds and mammals have 4 chambered heart. Single Circulation Blood flows through heart once in a circulation. Such kind of blood circulation is called single circulation.(Fishes have only one atrium and one ventricle) Eg: Fish, Amphibians Blood Pressure Normal Blood pressure (BP) of human being is 120/80. The instrument used to measure the BP is Sphygmomanometer. Blood Vessels Three kinds of blood vessels 1. Arteries 2. Veins 3. Capillaries Arteries are the blood vessels that carry blood away from the heart. Veins are the blood vessels that bring blood to heart. Capillaries help in the exchange of materials between blood and surrounding cells or tissues. QUESTION: Write the differences between arteries and veins. Arteries Veins Carry blood away from the heart Carry blood towards the heart Carry oxygenated blood except Carry deoxygenated blood except pulmonary artery pulmonary vein Do not have valves Veins have valves to prevent backward flow of blood. Thick muscular wall since blood flows Thin muscular wall since blood flows with jerk with less force Functions of lymph (Tissue Fluid) Lymph is the extracellular fluid similar to plasma but colourless with lesser protein i) It transports fat- and fat-soluble vitamins. ii) It protects the body from disease causing germs (DIFFERENCES BETWEEN BLOOD AND LYMPH) THINK Blood is red colour due to the presence of haemoglobin whereas lymph is colourless. Blood has more protein whereas lymph has less protein.  Transport system in Plants In highly organized plants, two kinds of conducting tissues – xylem and phloem.  Xylem conducts water from the plants from roots to leaves.  Phloem transports food from leaves to other parts of plants. Transport of water through xylem  Xylem helps in the transportation of water and minerals from the roots to leaves.  Xylem is made up of four kinds of cells - Tracheid, Vessels, Xylem Parenchyma and Xylem fibres  Water enters root cells by osmosis.  As a result, a root pressure (hydrostatic pressure) develops in root ells, which pushes the plant sap (Absorbed water and minerals) upwards through xylem up to few meters of height.  When the transpiration proceeds, a suction force (transpiration pull) is created which pulls the water upwards to leaves through xylem. Transport of food through Phloem Phloem helps in transportation of food from leaves to other parts of plants Phloem consists of sieve tubes, companion cells, Phloem parenchyma etc.  Food is transported in the form of sucrose.  Sucrose is transferred in to phloem tissue from leaf cells by using energy from ATP.  As a result, osmotic pressure in phloem tissue increases, which pushes the materials downwards. Translocation The process of transportation of food from leaves to other parts of plants through phloem is called translocation. What are the differences between transport of materials in xylem and phloem? Transport of materials in xylem Transport of materials in phloem Xylem tissue helps in the transport of Phloem tissue helps in the transport of water and minerals roots to leaves food from leaves to other parts Water is transported only in upward Food is transported both in upward and direction from the roots downward directions Transpiration in xylem occurs with the Transport of food in phloem require help of simple physical forces such as energy from ATP transpiration pull  Excretion The process of removal of metabolic wastes from the body is called excretion Human Excretory System Human excretory system consists of a pair of kidneys, a pair of ureter, a urinary bladder and a urethra. ( Diagrams) Kidneys Kidneys are located in the abdomen, on either side of back bone. Function of kidneys 1. The kidneys filter the blood and helps in the formation of urine. 2. It maintains the water and salt balance in the body. (Osmoregulation) Ureter: It is the tube that connects kidney and urinary bladder. Function of ureter: It carries urine from the kidney to urinary bladder Function of urinary bladder: it is the muscular sac that stores urine temporarily. Function of urethra: It is the tube that passes urine to outside. Nephrons Nephrons are the structural and functional units of kidney. Function of nephrons Nephrons filters the metabolic wastes from the blood and help in the formation of urine. Structure of nephron (Describe the structure and functioning of nephron.) Each nephron has two parts. 1. Bowman’s capsule and 2. Renal tubule Bowman’s capsule It is the cup shaped part of nephron. Bowman’s capsule contains network of capillaries called glomerulus. It opens into renal tubule Renal tubule Function of Glomerulus --- Ultrafiltration Function of Bowmans capsule --- Receives glomerular filtrate Renal tubule has three parts.  1. Proximal convoluted tubule (PCT) 2. Loop of Henley 3. Distal convoluted tubule(DCT) DCT opens into collecting duct. Collecting duct is connected to ureter. Function of Renal artery Renal artery is the blood vessel that brings oxygenated blood to kidney. Function of Renal vein It is the blood vessel that carries deoxygenated blood from the kidney. Process of urine formation Renal artery brings oxygenated blood to kidney, which contains metabolic wastes like urea and uric acid. When the blood flows through the glomerulus, urea, uric acid, water, small quantity of glucose, amino acids etc. are filtered in to bowman’s capsule. When this filtrate passes through renal tubule useful substances like glucose, amino acids, salts and water are selectively reabsorbed. After reabsorption, the filtrate enters collecting duct where it is called as urine. From the collecting duct, urine passes to ureter. QUESTION: How does kidney regulate the production of urine? The amount of water reabsorbed depends on how much excess water in the body and on how much of dissolved waste there is to be excreted. Excretion in plants. (QUESTION: How does plants get rid of waste materials?) Plants use varieties of techniques to get rid of waste materials. For example, waste material may be stored in the cell vacuole or as gum and resin, removed in the falling leaves or excreted in to the surrounding soil. Oxygen is the waste product formed during photosynthesis. It is liberated through stomata. Excess water is removed by transpiration. QUESTIONS 1. Why is diffusion insufficient to meet the oxygen to meet the requirements of multicellular organisms like humans? Multicellular organisms like humans possess a complex body designs. They have specialized cells and tissues for performing various necessary functions of the body such as intake of oxygen and food. Unlike unicellular organisms, multicellular cells are not in direct contact with the outside environment. Therefore, diffusion cannot meet their oxygen requirements. 2. What criteria do we use to decide whether something is alive? Any visible movement such as walking, breathing, or growing is generally used to decide whether something is alive or not. However, a living organisms can also have movements, which are not visible to the naked eye. Therefore, the presence of life processes is a fundamental criterion that can be used to decide whether something is alive or not. 3. What are the outside raw materials used by an organism?  An organism uses outside raw materials mostly in the form of food and oxygen. The raw materials required by an organism can be quite varied depending on the complexity of the organism and its environment. 4. What advantage over an aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration? Terrestrial take up oxygen from the atmosphere, whereas aquatic animals need to utilize oxygen present in the water. Air contains more oxygen when compare to water. Since the amount of oxygen is high in the air, the terrestrial animals do not have to breath faster to get enough oxygen. Therefore, unlike aquatic animals’ terrestrial animals do not have to show various adaptations for gas exchange. 5. Compare the functioning of alveoli in the lungs and nephrons in the kidney with respect to their structure and functioning. Alveoli in lungs Nephrons in Kidneys Structure Alveoli are tiny balloon like structures Nephrons are the tube lie structures present inside the lungs present in kidneys The wall of alveoli are thin and Nephrons are made up of glomerulus, surrounded by capillaries bowman’s capsule and renal tubule. Function It helps in exchange of gases It helps in the filtration of nitrogenous between alveoli and blood in waste like urea, uric acid etc. from the capillaries blood and helps in the formation of urine