CBSE Class 10 Science Notes - Life Processes PDF

Introductio All living organisms have certain common characteristics such as breathing, growing, requiring nutrition, producing offspring, responding to stimuli, etc. that distinguish them from non-living things. There are certain vital processes that maintain homeostas...

Introductio All living organisms have certain common characteristics such as breathing, growing, requiring nutrition, producing offspring, responding to stimuli, etc. that distinguish them from non-living things. There are certain vital processes that maintain homeostasis and proper functioning of the body, they are called life processes. These processes continue to occur even when we are sleeping or not performing any action. These processes are essential for all living organisms including plants and animals. These life processes are nutrition, photosynthesis, transportation, metabolism, respiration, reproduction and excretion In this chapter, we will learn about the details of these processes occurring in plants, animals and human beings in particular Lif Earth happens to be the only known planet having a life. There are beings who live, die and become part of nature again. The living organism can be differentiated from the inanimate entities on various parameters of life processes Life Proces e. s n..  The maintenance of living organisms is essential even if they are moving, resting or even sleeping The processes which together perform the function of maintenance of 'life' are called as life processes Nutrition, respiration, circulation, and excretion are examples of essential life processes In unicellular organisms, all these processes are carried out by a single cell In multicellular organisms, well-developed systems are present to carry out the processes To know more about Life Process, visit here Students can refer to the short notes and MCQ questions along with a separate solution pdf of this chapter for quick revision from the links below Life Processes Short Notes Life Processes MCQ Practice Questions Life Processes MCQ Practice Solutions... :...  Nutritio Nutritio The process of acquiring food that is needed for nourishment and sustenance of the organism is called nutrition There are two main modes of nutrition, autotrophic and heterotrophic Autotrophic nutrition is present in plants, algae and some bacteria. Organisms produce their own food using light energy or chemical energy by photosynthesis or chemosynthesis, respectively Heterotrophic nutrition is present in bacteria, fungi and animals. They derive energy from organic compounds. Such as animals eating plants or other animals for food Heterotrophic nutrition has subtypes such as holozoic, saprophytic and parasitic nutrition To know more about Nutrition, visit here Autotrophic Nutritio If an organism can nourish itself by making its own food using sunlight or chemicals such mode of nutrition is called as autotrophic nutrition Plants photosynthesize (use light energy) and are called photoautotrophs Few bacteria use chemicals to derive energy and are called chemoautotrophs. n n n........ Photosynthesi Photosynthesis is an important process by which food is formed The plants make food using sunlight and water, which provides nourishment to other organism and themselves Chlorophyll present in the green parts absorbs light energy This light energy is used to split water into hydrogen and oxygen Hydrogen is then used to reduce carbon dioxide into carbohydrates, typically glucose Chlorophyll is essential for photosynthesis and stomata to facilitate intake of carbon dioxide The overall reaction occurring in photosynthesis is as follows 6CO2 + 6H2O → C6H12O6 + 6O2 To know more about Photosynthesis, visit here. s.. :....  Stomat Stomata are pores on the leaves that help in the exchange of gases They are mostly found on the underside of the leaf Each stoma is guarded by guard cells, which control the opening and closing of the pore The water content of the guard cells is responsible for their function To know more about Stomata, visit here Saprophytic Nutritio Some organisms feed on dead and decaying organic matter. This mode of nutrition is called saprophytic nutrition The food is partially digested outside the body and then it is absorbed E.g. Fungi are saprophytes Parasitic Nutritio Some organisms feed at the expense of another organism and in turn cause harm. This is called the parasitic mode of nutrition These parasites live on the body or in the body of a host organism and derive the nutrients directly from the body of the host E.g. Leech is an ectoparasite while Ascaris is an endoparasite. Cuscuta is a parasitic plant a. n n..........  Nutrition in Amoeb Amoeba feeds by holozoic mode of nutrition It engulfs the food particle using pseudopodia, the process is called phagocytosis The engulfed food gets enclosed in a food vacuole As the food vacuole passes through the cytoplasm, digestion, absorption and assimilation take place When the food vacuole opens to outside, the egestion of undigested food takes place. a.... To know more about Nutrition in Amoeba, visit here Nutrition in Paramoeciu Paramoecium also exhibits holozoic nutrition However, they have cilia that help them to engulf the food through the oral groove A food vacuole is created enclosing the food It moves through the cytoplasm, the process is called cyclosis Food digested in the food vacuole is absorbed by the cytoplasm Undigested food is given out to a tiny pore called anal pore or cytopyge m.......  Nutrition in Human Humans are omnivores, they can eat plant-based food as well as animal-based food Being more complex, humans have a very complicated nutrition system The digestive system has an alimentary canal and associated digestive glands, which together function to nourish the body There are ve stages in human nutrition; Ingestion, Digestion, Absorption, Assimilation and Egestion Four stages i.e. ingestion, digestion, absorption and egestion take place in the alimentary canal while assimilation of food takes place in the whole body To know more about Nutrition in Humans, visit here Alimentary Cana The alimentary canal in humans is a long tube of varying diameter It starts with the mouth and ends with the anus Oesophagus, stomach, small intestine and large intestine are the parts of the alimentary canal. fi l s........  To know more about Alimentary Canal, visit here Mout h.  It is the opening of the alimentary canal and helps in the ingestion of food The buccal cavity which is present behind the mouth is also commonly referred to as the mouth The buccal cavity has teeth and a tongue The set of teeth helps in the mastication of food The tongue has taste buds on it and thus helps in tasting the food The salivary glands open also in the buccal cavity and pour saliva which initiates the process of digestion Teet Teeth are the hard structures present in the buccal cavity They help us to cut, shear and masticate the food we eat The vertical section of a tooth shows four layers enamel, dentine, cement and dental pulp Enamel is the outermost, shiny, highly mineralized and the hardest part of the human body Dentine makes the bulk of the tooth and contains 70% inorganic salts Cement is present at the lining of a tooth and bony socket The dental pulp is the central soft part of a tooth and contains nerve endings, blood and lymph vessels along with connective tissue There are four types of teeth in humans, Incisors, canines, molars and premolars, each with a speci c function Incisors cut the food, canines tear the food while molars and premolars crush it The dental formula in adult humans is 2:1:2:3 fi h................  Oesophagus & Stomac Oesophagu The swallowed food passes into the oesophagus It is a muscular tube, about 25 cm long, with a sphincter (valve/opening) at each end Its function is to transport food and uid, after being swallowed, from the mouth to the stomach Food is pushed down by peristaltic movements Stomac h s h fl....  The stomach is a thick-walled bag-like structure It receives food from the oesophagus at one end and opens into the small intestine at the other end The inner lining of the stomach secretes mucous, hydrochloric acid and digestive juices Food is churned into a semi-solid mass in the stomach and is called chyme Enzymes present in the gastric juice break down the food Hydrochloric acid helps in the partial digestion of proteins and also kills harmful bacteria The mucus secreted by the wall of the stomach resists the action of HCl on itself Small Intestin The small intestine is the longest part of the alimentary canal, about 20 feet long in humans It has regions, duodenum, the region which follows the stomach, jejunum is the middle part and the ileum is the later region which continues further into the large intestine The internal surface of the small intestine is folded into nger-like projections called villi A common pancreatic duct from the pancreas and liver opens into the duodenum Most of the chemical digestion and absorption take place in the small intestine Large Intestin The large intestine in humans is about 5 feet long It has two regions, colon ( about 1.5 m) and rectum (10 cm in length in the adult) The region of large intestine after ileum is called colon while the last part is called the rectum Colon has three regions as, ascending colon, transverse colon and descending colon At the base of the ascending colon, a small nger-like out-growth is seen and is called an appendix It houses many useful bacteria required for digestion of food.. e e fi.. fi..............  Rectum opens to outside by anus The anus has internal and external anal sphincters Peristalsi A constant wave-like movement of the alimentary canal right from the oesophagus to the small intestine is called as peristalsis Muscles present in the wall of the alimentary canal are responsible for peristalsis This movement helps to push the food through the alimentary canal To know more about Peristalsis, visit here Digestive Gland Several glands produce digestive juices that help in digestion of the food Salivary glands, Gastric glands, Liver, Gallbladder, Pancreas are few to name Salivary glands secrete saliva which initiates digestion in the mouth itself Gastric glands present in the wall of the stomach secrete hydrochloric acid and enzyme pepsin The liver secretes bile which is stored in the gallbladder. Bile helps in digestion of fats The pancreas secretes many digestive enzymes and its secretion is called as pancreatic juice s s............  Enzymes like trypsin, chymotrypsin, lipase, amylase are present in the pancreatic juice Pancrea The pancreas is a long, at gland present behind the stomach in humans It is one of the major digestive glands and is of mixed nature i.e. endocrine as well as exocrine As an endocrine organ, it secretes two hormones called insulin and glucagon which maintain the blood sugar level As an exocrine gland, it secretes pancreatic juice which is nothing but a mixture of many digestive enzymes The digestive enzymes secreted by the pancreas include trypsin and chymotrypsin and proteases which digest proteins It also includes amylase which digests the starch content of the food Pancreatic lipases are the pancreatic enzymes that help in digestion of fats To know more about Pancreas, visit here Holozoic Nutritio The mode of nutrition in which animals take their food as a whole is called as holozoic nutrition s... n fl.......  In holozoic nutrition, food passes through ve steps as ingestion, digestion, absorption, assimilation and egestion Physiology of Digestio Mechanical digestion of food takes place in the buccal cavity where teeth masticate the food, saliva gets mixed and it turns into a bolus Digestion of starch starts in the buccal cavity itself, with the action of salivary amylase present in the saliva Salivary amylase converts starch into maltose In the stomach, the churning of food takes place due to the muscular contraction and relaxation of its wall. It breaks down the food into simpler substances Digestion of proteins starts in the stomach with the action of pepsin. Proteins are broken down into smaller fragments called peptide by the action of pepsin The bolus after mixing with gastric juice, turn into a ne soluble form known as the chyme Chyme enters into the small intestine where complete digestion takes place due to the action of various enzymes present in the pancreatic juice, bile and intestinal juice The digested food is completely absorbed by the villi and microvilli of the small intestine Undigested food then enters into the large intestine The colon is responsible for absorption of water and salts whereas rectum stores the undigested food temporarily before defaecation To know more about Digestive System, visit here Digestive System in Other Animal Digestive systems in different animals vary in structure and function The structure of the digestive system depends on the food habits of the animal Alimentary canal in herbivores is long as the cellulose content of their plant-based diet takes a long time to digest On the other hand, the alimentary canal of carnivorous animals is comparatively shorter because meat gets digested faster Anatomy of Digestive Trac The alimentary canal in humans is approximately 30 feet (9m) long. It is also called the gastrointestinal tract It starts with the mouth and ends in the anus Between these two openings, the alimentary canal is a tube of varying diameter Oesophagus, stomach, small intestine (divided into three regions duodenum, jejunum and ileum) and large intestine(having two regions colon and rectum) are the parts of the alimentary canal Salivary glands, pancreas and liver act as major digestive glands Glands present in the wall of the stomach and small intestine also contribute to the digestion of food...... n t.. s fi.... fi..........  Role of HC Hydrochloric acid in the stomach is secreted by the gastric glands present in its wall the pH of the gastric acid is usually between 1.5 to 3. This acid serves the following functions 1. Converts inactive pepsinogen and pro-rennin into active pepsin and rennin respectively 2. Provides an acidic medium for protein digestion 3. Kills bacteria entered through food and prevents infection 4. Prevents putrefaction of food in the stomach A thick layer of mucus secreted by the mucous glands of the stomach prevents itself from the action of gastric acid Excess acid damages gastric mucosa and causes gastric and duodenal ulcers Salivary Gland Salivary glands are the exocrine glands that secrete saliva and through a system of ducts, it is poured into the mouth In humans, three major pairs of salivary glands are present, parotid, submandibular and sublingual In healthy individuals between 0.5 to 1.5 litres of saliva is produced per day Saliva serves the following functions in the oral cavity 1. It lubricates and protects the soft and hard tissues of the oral cavit 2. It also gives protection from dental carie 3. Saliva prevents microbial growth in the oral cavity 4. Saliva can encourage soft tissue repair by decreasing clotting time and increasing wound contractio 5. Saliva contains the enzyme amylase that hydrolyses starch into maltose and dextrin. Hence saliva allows digestion to occur before the food reaches the stomac 6. Saliva acts as a solvent in which solid particles can dissolve in and enter the taste buds located on the tongue n. l s... : s... 5 :. y h....  Heterotrophic Nutritio When an organism depends on others for food, such a mode of nutrition is called as a heterotrophic mode of nutrition These organisms depend on autotrophs for their nutritional requirements E.g. Animals which eat plants as their food are called herbivores Animals which eat other animals as their food are called carnivores Holozoic, saprophytic and parasitic nutrition are all types of heterotrophic nutrition To know more about Heterotrophic Nutrition, visit here Glandular Epitheliu Many small glands present in the inner layer of the stomach and intestine take part in the digestion of food These glands are present in the epithelial lining of the stomach and intestine  .. m n......  The glands present in different regions of the stomach are called gastric glands They are responsible for the secretion of mucus, hydrochloric acid and enzymes like pepsinogen The glands present in the epithelial lining of the small intestine and large intestine are called intestinal glands Glands of the small intestine are responsible for the secretion of intestinal juice also called succus entericus Intestinal juice contains hormones, digestive enzymes, alkaline mucus, and substances to neutralize hydrochloric acid coming from the stomach Intestinal juice completes the digestion started by the pancreatic juice Glands of the large intestine are associated with the absorption of water and electrolytes Villi and Micro Vill Complete digestion and absorption of food take place in the small intestine Pancreatic juice coming from the pancreas, bile from the liver and intestinal juice secreted by the intestinal glands complete the digestion of food material All the digested nutrients are absorbed by the long nger-like projections present in the ileum of the small intestine These small nger-like projections of the inner wall of intestine are called as villi (singular: villus) Each villus has its cell membrane of the lumen side again folded into microscopic processes, called microvilli Villi increase the internal surface area of the intestinal walls making available a greater surface area for absorption Digested nutrients pass into the semipermeable villi through diffusion Villi also help in chemical digestion of food by secreting digestive enzymes. fi..... i fi.........  Live   r  The liver is the largest and major digestive gland of human Liver, in humans, is located in the upper right-hand portion of the abdomen This organ is dark reddish-brown in colour due to an extensive blood supply Some of the important functions of the liver are as follows 1. It secretes bile that helps in digestion 2. It lters the blood coming from the digestive tract before passing it to the rest of the body 3. It detoxi es various metabolites and antidote 4. The liver makes proteins important for blood clotting and other functions 5. It stores and releases glucose as needed 6. It processes haemoglobin, from the dead and worn out RBCs, for the iron content (the liver stores iron) 7. Conversion of harmful ammonia to urea takes place in the liver To know more about Liver, visit here Digestive Juice fi fi. s.... : s.....  Pancreatic juice, bile and intestinal juice (succus entericus) are collectively called digestive juices A common duct from digestive glands pours the secretions into the duodenum Chyme enters the small intestine where complete digestion takes place due to the action of various enzymes In the duodenum, the acidity of chyme is turned to alkalinity by the action of bile coming from the liver. This is necessary for pancreatic enzyme action Bile also emulsi es the fats into smaller globules Pancreatic and intestinal amylases break down carbohydrates into glucose Trypsin and chymotrypsin are the proteases responsible for the breakdown of proteins nally into amino acids Lipase is the enzyme which acts on the emulsi ed fats and breaks them down into glycerol and fatty acids Water Absorption in Large Intestin The large intestine is not involved in the digestion of food or absorption of nutrients The major function of the large intestine is to absorb water from the remaining indigestible food matter and make the stool solid The large intestine also helps in the absorption of vitamins made by bacteria that normally live in the large intestine The innermost layer of the large intestine also acts as a barrier and protects from microbial infections and invasions Rectum stores the undigested food temporarily until defecation Respiratio Introduction to Respiratio Respiration broadly means the exchange of gases Animals and plants have different means of exchange of gases At a cellular level, respiration means the burning of the food at the for generating the energy needed for other life processes Cellular respiration may take place in the presence or absence of oxygen... fi n..... n e fi......... fi  To know more about Respiration, visit here Respiration in Human The human respiratory system is more complex and involves breathing, exchange of gases and cellular respiration A well de ned respiratory system helps breathing and exchange of gases Breathing involves the inhalation of oxygen and exhalation of carbon dioxide The gaseous exchange takes place in the lungs and oxygen is supplied to all cells of the body Cellular respiration takes place in each and every cell Respiratory Syste The human respiratory system involves the nose, nasal cavities, pharynx, larynx, trachea/ windpipe, bronchi, bronchioles and alveoli Bronchioles and alveoli are enclosed in a pair of lungs The rib cage, muscles associated with the rib cage and diaphragm, all help in inhalation and exhalation of gases Exchange of gases takes place between an alveolar surface and surrounding blood vessels Alveoli provide a large surface area for exchange of gases To know more about Respiratory System, visit here Physiology of Respiratio Breathing in humans is facilitated by the action of internal intercostal and external intercostal muscles attached to the ribs and the diaphragm When the dome-shaped diaphragm contracts and becomes attened and the rib cage is expanded due to the action of intercostal muscles, the volume of the lungs increases, pressure there drops down and the air from outside gushes in. This is inhalation fi.. m s n........ fl....  To exhale, the diaphragm relaxes, becomes dome-shaped again, chest cavity contracts due to the action of intercostal muscles, the volume inside the lungs decreases, pressure increases and the air is forced out of the lungs Inhaled air increases the concentration of oxygen in the alveoli, so oxygen simply diffuses into the surrounding blood vessels Blood coming from cells has more concentration of carbon dioxide than outside air and thus carbon dioxide simply diffuses out of the blood vessels into the alveoli Thus, breathing takes place due to the combined action of intercostal muscles and diaphragm while the exchange of gases takes place due to simple diffusion Inhalation and Exhalatio The process of taking in air rich in oxygen is called inhalation Similarly, the process of giving out air rich in carbon dioxide is called exhalation One breath comprises one inhalation and one exhalation A person breathes several times in a day The number of times a person breathes in one minute is termed as his/her breathing rate To know more about Inhalation and Exhalation, visit here Diffusio   n.. n........  Diffusion is the movement of molecules from high concentration area to the low concentration area without spending any energy Cellular Respiratio Cellular respiration is set of metabolic reactions occurring inside the cells to convert biochemical energy obtained from the food into a chemical compound called adenosine triphosphate (ATP) Metabolism refers to a set of chemical reactions carried out for maintaining the living state of the cells in an organism. These can be divided into two categories Catabolism – the process of breaking molecules to obtain energy Anabolism – the process of synthesizing all compounds required by the cells Therefore, respiration is a catabolic process, which breaks large molecules into smaller ones, releasing energy to fuel cellular activities Glycolysis, Krebs cycle and electron transport chain are the important processes of the cellular respiration  . n.. :...  To know more about Cellular Respiration, visit here Aerobic Respiratio Aerobic respiration is a process in which the food i.e. glucose is converted into energy in the presence of oxygen The general equation of aerobic respiration as a whole is as given below Glucose + oxygen ⇒ Carbon dioxide + Water + Energ This type of respiration takes place in animals, plants and other living organisms Respiration in Lower Animal Lower animals lack a sophisticated respiratory system like lungs, alveoli etc Respiration in them takes place by simple exchange mechanisms Animals like earthworms take in gases through their skin Fishes have gills for gaseous exchange Insects have a tracheal system, which is a network of tubes, through which air circulates and gaseous exchange takes place Frogs breathe through their skin when in water and through their lungs when on land  . n. s.. y.. -...  Respiration in Muscle Respiration in muscles can be anaerobic when there is not enough oxygen Glucose gets broken down into carbon dioxide and lactic acid This results in the accumulation of lactic acid that makes the muscles sore This type of anaerobic respiration is also known as lactic acid fermentation AT It is the energy currency of the cell ATP stands for Adenosine Tri-Phosphate This molecule is created as a result reactions like photosynthesis, respiration etc The three phosphate bonds present in the molecule are high-energy bonds and when they are broken, a large amount of energy is released Such released energy is then used for other metabolic reactions P s.........  Respiration in Plant Unlike animals and humans, plants do not have any specialized structures for gaseous exchang They have stomata (present in leaves) and lenticels (present in stems) which are involved in the exchange of gases Compared to animals, plant roots, stems, and leaves respire at a very lower rate  . s. e To know more about Respiration in Plants, visit here Transpiratio Transpiration is a biological process in which water is lost in the form of water vapour from the aerial parts of the plants This process occurs mainly through the stomata where the exchange of gases (oxygen and carbon dioxide) occurs Transpiration helps in the transportation of water from roots to upper parts of plants and this is explained by 'transpirational pull theory' Loss of water, especially from leaves, acts as a straw effect and pulls water upwards from roots Transpiration also acts as an excretory mechanism in plants as it helps to get rid of excess water To know more about Transpiration, visit here Why Do We Need Lung. n. s.....  In unicellular organisms like an amoeba exchange of gases takes place through a general body surface by osmosis In lower animals like an earthworm, the gaseous exchange takes place through their moist skin The requirement for oxygen is suf ciently met in these ways But as the animal starts becoming more and more complex, for example, humans, the requirement of oxygen cannot be met alone by diffusion Moreover, diffusion will not be able to supply oxygen to the deep-seated cells This dif culty has led to the evolution of a more complex mechanism of gaseous exchange and that is the development of lungs The alveoli present in the lungs provide a large surface area required for the necessary gas exchange Read more: Facts about Lungs Transportation in Human Being fi... fi s....  Transportatio All living organisms need a few necessary components like air, water, and food for their survival On a regular basis, animals ensure these elements by breathing, drinking and eating The required elements are transported to their body cells and tissues by a transportation system In plants, the vascular tissue is responsible for transporting the substances Transportation in Human Transportation in humans is done by the circulatory system The circulatory system in humans mainly consists of blood, blood vessels and the heart It is responsible for the supply of oxygen, and nutrients, and the removal of carbon dioxide and other excretory products It also helps to ght infections To know more about Transportation in Animals and Plants, visit here Hear t fi n.. s.......  The muscular organ which is located near the chest slightly towards the left in the thoracic region The heart is the main pumping organ of the body The human heart is divided into four chambers which are involved in the transportation of oxygenated and deoxygenated blood The upper two chambers are called atria whereas the lower two chambers are called as ventricles....  To know more about Human Heart, visit here The ow of blood through the heart is as follows Blood Vessel Blood vessels carry blood throughout the body There three types of blood vessels; arteries, veins and blood capillaries Arteries carry oxygenated blood and veins carry deoxygenated blood Gaseous exchange takes place between blood and cells at capillaries Difference between Arteries and Veins fl s.. :...  Blood Pressur The pressure exerted by the blood when it ows through the blood vessels is called blood pressure There are two different variants of blood pressure; systolic and diastolic blood pressure The pressure exerted on the walls of arteries when the heart is lling with blood is called diastolic pressure. It constitutes the minimum pressure on arteries The normal range of diastolic blood pressure should be 60 – 80 mm Hg The pressure exerted on the walls of arteries when the heart is pumping the blood is called systolic pressure. It constitutes the maximum pressure applied to the arteries The normal range of systolic blood pressure should be 90 – 120 mm Hg To know more about Blood Pressure, visit here Bleedin Bleeding occurs when the blood vessels rupture Bleeding is stopped by the platelets that help in the clotting of blood at the site of the injury Blood Clotting is the process of forming a clot in order to prevent excess loss of blood from the body It is a gel-like mass which is formed by the platelets and a bre-like protein in the blood  . g e fl.. fi fi........  Double Circulatio In the human body, blood circulates through the heart twice Once it goes through the heart during pulmonary circulation and second time during systemic circulation Hence, circulation in human beings is called double circulation. n..  To know more about Double Circulation, visit here Transportation in Plant Transportation in Plant Transportation is a vital process in plants The process involves the transportation of water and necessary nutrients to all parts of the plant for its survival Food and water transportation takes place separately in plants Xylem transports water and phloem transports food To know more about Transportation in Plants, visit here Phloe   m. s s.....  The phloem is responsible for translocation of nutrients and sugar like carbohydrates, produced by the leaves to areas of the plant that are metabolically active Sieve tubes, companion cells, phloem bres, and phloem parenchyma cells are the components of this tissu The ow of material through phloem is bidirectional Translocatio Transport of food in the plant through phloem via a process such as mass ow is called as translocation. Photosynthates i.e. sugars and organic molecules such as amino acids, organic acids, proteins and inorganic solutes like potassium, magnesium, nitrate, calcium, sulfur and iron from source tissues (mature leaves) to the sink cells (areas of growth and storage) are transported through the phloem Material like sucrose is loaded from leaves to phloem using the energy of ATP Such a transfer increases the osmotic pressure causing the movement of water from nearby cells into phloem tissue and the material gets transported through the phloem The same pressure is also responsible for the transfer of substances from phloem to tissues where food is required Thus the bulk ow of material through phloem takes place in response to an osmotically generated pressure difference   fl. e fl n.. fi... fl.  Xyle Xylem tissue transports water in plants from root to all other parts of the plant Xylem tissue is made up tracheids, vessels, xylem bres and xylem parenchyma The ow of water and minerals through xylem is always unidirectional   fl m fi... Root Pressur Conduction of water through the xylem, from roots to upper parts of plants, is due to many forces acting together One of the forces responsible for this is root pressure Root pressure is osmotic pressure within the cells of a root system that causes sap to rise through a plant stem to the leaves Root pressure helps in the initial transport of water up the roots e....  To know more about Root Pressure, visit here Transport of Wate Water is absorbed by the roots and is transported by xylem to the upper parts of the plant Imbibition, osmosis, root pressure and transpiration are the forces that contribute towards the upward movement of water, even in the tallest plants Imbibition is a process in which water is absorbed by the solids. E.g. seeds take up water when soaked Osmosis is a process where water moves from the area of its lower concentration to the area of its higher concentration At the roots, the cells take up ions by an active process and this results in the difference of concentration of these ions It leads to movement of water, in the root cells, by osmosis This creates a continuous column of water that gets pushed upwards. This is root pressure Transpiration contributes to the upward movement of water by creating a staw effect It pulls the water column upwards as there is a continuous loss of water from leaves All these forces act together for water transport through the xyle Excretion in Human Excretio Excretion is the process of removal of metabolic waste material and other non-useful substances Organisms like animals have an advanced and specialized system for excretion But plants lack a well-developed excretory system like that in animals They do not have special organs for excretion and thus excretion in plants is not so complex Excretion in Unicellular Organism In unicellular organisms such as amoeba and bacteria, the waste product is removed by simple diffusion through the general body surface Unicellular organisms like the amoeba, and paramecium excrete excess through tiny organelles called contractile vacuoles Undigested food in unicellular animals is excreted when the food vacuole merges with the general body surface and opens to the outside Excretory System of Human The excretory system in humans include ◦ a pair of kidneys ◦ a pair of ureters. n , , r... s s s. s.... m........  ◦ a urinary bladder an ◦ urethra It produces urine as a waste product To know more about Human Excretory System, visit here Kidney Paired kidneys are the main excretory organs of the body They are basically the ltration units of the human body Each kidney is made up of many tiny ltration units called nephrons Kidneys perform crucial functions like 1. Filtering waste materials, medications, and toxic substances from the blood 2. Regulation of osmolarity i.e. uid balance of the body 3. Regulation of ion concentration in the body 4. Regulation of pH 5. Regulation of extracellular uid volume 6. Secreting hormones that help produce red blood cells, promote bone health, and regulate blood pressur Nephro Nephrons are the structural and functional unit of kidney Each kidney has millions of nephrons and it forms the basic structural and functional unit of the kidney.. s n e. d fi fl fl. fi :.........  Each nephron has two parts: Malpighian body and renal tubule Malpighian body is made up of cup-like structure called Bowman's capsule which encloses a bunch of capillaries called glomerulus They together lter waste materials along with many useful substances Renal tubule has regions called proximal convoluted tubule, Loop of Henle and distal convoluted tubule These regions absorb back useful substances into the blood and also lter remaining waste substances The output from nephrons is called urine Haemodialysi ◦ When the kidneys fail, it results in a lot of complications and to compensate this situation a technology called dialysis has been developed ◦ It uses a machine lter called a dialyzer or arti cial kidney ◦ This is to remove excess water and salt, to balance other electrolytes in the body and remove waste products of metabolism  .. fi s fi... fi... fi.  ◦ Blood from the body is removed and owed through a series of tubes made up of a semipermeable membrane ◦ A dialysate ows on the other side of the membrane, which draws impurities through the membrane Excretion in Plant The cellular respiration, photosynthesis, and other metabolic reactions produce a lot of excretory products in plants Carbon dioxide, excess water produced during respiration and nitrogenous compounds produced during protein metabolism are the major excretory products in plants Plants produce two gaseous waste products i.e. oxygen during photosynthesis and carbon dioxide during respiration. fl.. s. fl.  Excretion of gaseous waste in plants takes place through stomatal pores on leaves Oxygen released during photosynthesis is used for respiration while carbon dioxide released during respiration is used for photosynthesis Excess water is excreted by transpiration Organic by-products generated by the plant are stored in different forms in different parts The gums, oils, latex, resins, etc. are some waste products stored in plant parts like barks, stems, leaves, etc Eventually, plants shed off these parts Few examples of the excretory products of plants are oil produced from orange, eucalyptus, jasmine, latex from the rubber tree, papaya tree, and gums from acacia Sometimes plants even excrete into the soil To know more about Excretion in Plants, visit here Also Check: CBSE Class 10 Chapter 5 Periodic Classi cation of Elements Notes CBSE Class 10 Science Chapter 7 Control and Coordination Notes NCERT Solutions for Class 10 Science Chapter 6 Life Processes NCERT Exemplar Class 10 Science Solutions for Chapter 6 - Life Processes Real Numbers Class 10 Notes: Chapter 1 CBSE Class 10 History Notes Chapter 1 - The Rise of Nationalism in Europe Frequently Asked Questions on Life Processe  ... fi.. s.... Q. The instrument used for measuring blood pressure is called Ans. A sphygmomanometer is an instrument used for measuring blood pressure Q. The phloem tissue in plants is responsible for doing which function Ans. Phloem is the vascular tissues that is responsible for the transport of substances in plant Q. Why aerobic respiration produces more usable chemical energy than fermentation Ans. Aerobic respiration produces more usable chemical energy in the form of ATPs than fermentation because aerobic respiration involves the complete oxidation of glucose and the release of carbon dioxide and water as end products. ? ?. ? s