aang PE 23425 ede SET Ot Nutrition Nutrition ‘The process by which organisms obtain and utilize nutrients for their growth, development and maintenance is called nutrition and the various inorganic and organic substances present in food are called nutrients. Modes of nutrition Methods of obtaining food by the organisms are called modes of nutrition. Modes of nutrition rr Autotrophic nutrition Heterotrophic nutrition Holozoic nutrition Saprotrophic nutrition Parasitic nutrition Nutrition in Plants Plants obtain their nutrition by two modes, autotrophic and heterotrophic. Autotrophic nutrition in plants Autotrophic nutrition (in Greek: auto-self, troph-nourishment) is a mode of nutrition where organism synthesize its own food from the inorganic raw materials with the help of energy. For example, green plants prepare their food by using carbon dioxide and water in the presence of chlorophyll and sunlight. G4)r Olympiads: Class 10 ALLEN’ © Photosynthesis: is the process of preparing organic food (carbohydrate) by combining carbon dioxide and water, using solar energy by chlorophyll pigments. It is anabolic process Load sugar (glucose) Photosynthesis 6CO, + 12H,O—Sie 5C,H,,0, +6H,0+60, 7 (from air) (from soil) (Glucose © Requirements for photosynthesis Sunlight Sun is a natural source of light for photosynthesi Photosynthetic pigments These are chlorophylls which are responsible for absorbing light energy. Photosynthetic pigments are present in all the green parts of the plant. 3. Carbon Dioxide All the plants need carbon dioxide to form carbohydrates. The carbon dioxide is obtained by the plants from the atmospheric air. In the terrestrial plants, the CO2 enters into the cells of leaves through tiny pores called stomata which always remain present on the surface of leaves. Water i \ i i e Water is always needed by the plants for its use during photosynthesis, It is absorbed by the roots of the plant from the soil through the process of osmosis. Inside the chloroplasts of the leaves, the water molecules split into hydrogen and } oxygen with the help of light energy of the sun. : © Site of photosynthesis i » The leaves contain specialised cells called mesophyll cells which contain chloroplasts, || i the pigment containing organelle. These are the actual sites for photosynthesis.rey. iters sent bed and ists, | j \PMCS\E24 2h ModE Obrint Peahig PCH 22425 Mode SE oppo 206 aen\ OLY Huo Theary —_ Biology Lamina Vein ‘Xylem anid phloem Vascular bundle axy cuticle Vacuole Upper epidermis Chloroplast: Stroma thylakoid Grana Air spaces: Mesophyll cells Guard cell Lower epidermis {(a) Cross section of leaf (b) Chloroplast > The photosynthetic pigment, chlorophyll, is the principal pigment involved in photosynthesis. It is a large magnesium (Mg'2) containing molecule and absorbs violet, blue and red region light of the visible spectrum and reflects green light and thus leaves appear green in colour. > The role of the pigments is to absorb light energy, thereby converting it to chemical energy. These pigments are located on the thylakoid membranes of chloroplast. © Mechanism of photosynthesis > Photosynthesis comprises two sets of reactions: (i) Light reaction (ii) Dark reaction (i) Light reaction: It requires light and takes place in grana of chloroplast. It involves. (a) Absorption of light energy by chlorophyll. (b) Splitting of water molecules into hydrogen and oxygen i.e. photolysis. (©) Conversion of light energy into chemical energy (ATP and NADPH2). (ii) Dark reaction: It does not require light and takes place in stroma of chloroplast. In dark reaction reduction of CO; to carbohydrates takes place. Dark reaction Light energy. 12 #1210 GEE Calti20e + 6C02 +1211:0-Chigrophght> Célli206+ 6120 + 602 Light reaction What is Calvin cycle? Explanation Calvin cycle (Dark reaction) is a cycle of reaction that occurs during reduction of CO2 to carbohydrate with the help of ATP and NADPH: produced during light reaction. It occurs in| the stroma of chloroplast. [3]Olympiads: Class 10 ALLEN’ Difference between Light and Dark reactions ers rr Deen Requirement of Required Not required * ight Takes place | Grana part of the chloroplast. Stroma region of chloroplast. inside | ATP and ATP and NADPH? are produced by ATP and NADPH: formed during light NADPH: | the conversion of light energy into reaction are used for the fixation of CO2 chemical energy into carbohydrate ‘Sugar | No sugar formation takes place ‘Sugar formation takes place formation Release of Oxygen is released No oxygen is released oxygen © Factors influencing rate of photosynthesis > Environmental factors such as light, temperature, carbon dioxide concentration and water. > Internal factors which include age of leaf, chlorophyll content and leaf anatomy. m Stomata These are tiny pores or microscopic aperture guarded by two kidneys shaped or bean shaped guard cells. Guard cells Nucleus Stomatal pore Chloroplast i i a) @) i Open stomata Closed stomata 5 © Functions of stomata > Massive amount of gaseous exchange takes place in the leaves through stomata. Exchange of gases also occurs across the surface of stem and root. > Large amount of water is lost in the form of water vapour through stomataand this process is known as transpiration. © = Guard cells: These are kidney shaped cells which surround stoma, They contain chloroplast also. > Function of guard cells: They regulate the opening and closing of the stoma and also perform photosynthesis. © Opening and closing of stomata: When the guard cells swell (become turgid) due to the entry of water, the stomata gets opened. But when the guard cells shrink (become flaccid) due to the loss of water, the stomata gets closed. | Special points © First true and oxygenic photosynthesis started in cyanobacteria (blue green algae). ape emeeeetineneeeeaenemrT 0 ALLEN Biology ‘@ 90% of total photosynthesis is carried out by hydrophytes (mostly marine algae). fe r There are certain bacteria which can utilise chemical energy released during biological oxidation of certain inorganic substances to reduce carbon dioxide to carbohydrate. These bacte are called chemosynthetic autotrophs. @ — Chemosynthesis may be defined as the method of carbon assimilation when the reduction of CO2, takes place by utilising the energy obtained from oxidation of ae inorganic substances. pa The common chemosynthetic forms are: > _Nitrifying bacteria (Nitrosomonas oxidises NH3 to NO2) | > Sulphur bacteria » Iron bacteria > Hydrogen and methane bacteria © Generally, stomata open during day time and close during night time but in desert ter plants stomata open at night time to check excessive loss of water. © Desert plants take up CO2 at night and prepare an intermediate which is acted upon by the energy absorbed by the chlorophyll during the day and form glucose. 7 © Inaquatic plants, COz is obtained from the water where it remains present in dissolved form. Such plants absorb carbon dioxide in solution form by diffusion, through all over their surface from the surrounding water. © Nitrogen is an essential element used in the synthesis of proteins and other compounds (chlorophyll, DNA and RNA). Nitrogen is taken up in the form of inorganic nitrates or nitrites which have been prepared by symbiotic bacteria or free-living bacteria from pi atmospheric nitrogen. { 4 © Photophosphorylation: Production of ATP from ADP and inorganic phosphate by using 5G the energy of sunlight. = = @ _ Photolysis is the splitting of water molecule in the presence of light. 1ge } = M — Heterotrophic nutrition in plants 315 Certain plants fail to synthesize their own organic nutrients from inorganic substances. ess & ‘These are thus dependent on some other external sources for their nutrition. Such plants ; are called heterotrophic plants and mode of nutrition is called heterotrophic nutrition. © Saprophytes = £ > Those plants which grow and live on rotting dead leaves e.g,, Indian pipe, Coral root ii and Monotropa. he | [ @ Parasitic Plants id) $ |} — Dodder (Cuscuta) locally known as Amarbel/Akashbel is a parasitic plant that lacks both chlorophyll and leaves, It is a yellow colour climber that attaches itself to the host. It gives out haustoria or the suckers that get attached to the phloem of the host and derive igs NCR nutrition. [5]Olympiads: Class 10 ALLE’ © Insectivorous Plants > ‘There are certain plants which are autotrophic but show heterotrophic nutrition as well in order to supplement the deficiency of a particular mineral (e.g. nitrogen) in the soil >" Insectivorous plants are the best examples. They feed on insects. They are generally found in nitrogen deficient habitats and hence to compensate the loss, they use insects as a source of nitrogen. > For example, Pitcher plant (Nepenthes); Sundew (Drosera); Venus flytrap (Dionaea); Bladderwort (Utricularia) © symbiotic relationship: Mutually beneficial association in which organisms live together and share shelter and nutrients is called symbiotic relationship. For example, Mycorrhiza and lichen, > Mycorr! he symbiotic association of the mycelium of a fungus with the roots of certain plants (conifers and orchids). The tree provides nutrients to the fungus and, in return, receives help from it to take up water and minerals from the soil. This association is very important for the tree as well as, the fungus. > Lichens: Association in which a chlorophyll-containing partner (algae) and a fungus live together. The fungus provides shelter, water and minerals to the algae and in return, the algae provide food which it prepares by photosynthesis. . Nutrition in animals © Heterotrophic nutrition: Mode of nutrition in which the organisms derive their nutrition by taking readymade food, from other dead or living plants and animals. The survival of heterotrophs depends directly or indirectly on autotrophs, e.g, Animals, fungi, some protists and most of bacteria. Heterotrophic mode of nutrition is classified into three types on the basis of methods of obtaining food. > Holozoic nutrition - Ingestive nutrition: Mode of nutrition in which, the animals take in s\n s0 08 complex solid food or whole material and break down (digestion) of the food takes place inside the body. They may be herbivores (Cow), carnivores (Lion) and omnivores (Rat). > Saprotrophic nutrition: In this type of nutrition the organisms obtain their food from dead, decaying organic substances. They are also called saprotrophs. They breakdown the food material outside the body by secreting digestive enzymes onto the matter and then absorb it. e.g, Bacteria, Fungi (bread moulds, yeasts and mushrooms). 3 i E > Parasitic nutrition: Mode of nutrition in which organisms (parasite) derive nutrition from other plants and animals (host) without killing them. e.g. Ticks, lice, leeches and tapeworms. [6]Yr rhe” ALLEN’ Biology @ _ Holozoic nutrition : There are five major steps in Holozoic nutrition. in ) __ Ingestion : Taking in of the food, its chewing or absorbing and swallowing. >. Digestion : Conversion of complex food into simpler absorbable form with the help of cd digestive enzymes. a > Absorption : Absorbing digested food from the gut and its transport to the body tissues or cytoplasm. ea) > Assimilation : Utilization of absorbed food nutrients by the body tissues. > __Egestion : Removal of undigested food from the body. @ Digestion can be of two types ) Intracellular Digestion (Intra = inside) : All the five steps of nutrition occur inside the sof cell itself, as in Amoeba, Paramecium and other unicellular organisms. Amoeba projects out pseudopodia to capture the food & forms a food vacuole. sup Food vacuoles are temporary structures and every time the Amoeba feeds, a new food llas vacuole is produced. The food is digested inside the vacuole, > Extracellular digestion (Extra - outside) : Digestion occurs outside the cell. Many live animals carry out extracellular digestion. They have either a cavity, a tube, or an alimentary the canal which receives the ingested food. Food is acted upon by digestive enzymes and the products of digestion are absorbed back into the cells lining the cavity. = The Human Digestive System tion § ‘The digestive system in human consists of an alimentary canal and associated digestive of glands. = | m Alimentary canal - i Itis long and continuous muscular digestive tube that runs from the mouth to anus. 3 ‘The alimentary canal has the following parts: ein § ace om the hen 1 5 i 2 B 5 i 71Olympiads: Class 10 ALLEN’ ary glands Mouth esophagus Liver Stomach Gall bladdei Pancreas Small Large intestine intestine Appendi Rectum “Anus Human digestive system Mouth Itis a transverse slit bounded by two soft movable lips. Buccal cavity Mouth leads into a large space known as mouth cavity or oral cavity or buccal cavity. vveve Four types of teeth are found in buccal cavity of humans: Incisors (biting the food), Canines (tearing of food), Premolars and Molars (crushing and grinding of food). The outer covering of teeth is called enamel and is the hardest substance of human body. > The floor of the mouth cavity is occupied by large, muscular, movable tongue. Itis the organ of taste with taste buds on its upper surface. © Pharynx: The buccal cavity opens into a short narrow chamber called pharynx. It is a common passage for the inhaled air and the swallowed food. © — Oesophagus: A 25 cm long narrow muscular, straight tube from pharynx, continuing through the thorax and ending in the stomach. It runs behind trachea, © Stomach: A wide, } shaped sac, with highly muscular walls which is placed on left side in upper part of abdomen. It contains numerous microscopic simple tubular glands called gastric Oesophagus glands. These release gastric juice which contains mucus, hydrochloric acid and two inactive protein digesting enzymes called pepsinogen and prorennin, ‘The muscular walls of the stomach help in mixing the food thoroughly with digestive juices, HCI activates pepsinogen to pepsin and prorennin to rennin. Pepsinogen —!°-s Pepsin W Prorennin—"“_yRennin Stomach [8] i itines yuter rgan uing de in nach ‘ettaingfPMCF\2024 25k Mode SET Ope 1 acO. OY Neon They hereon Tso Biology It produces an appropriate acidic medium (pH = 2). It facilitates the action of enzyme pepsin and kills the bacteria present in food. Pepsin breaks down proteins into peptides. Proteins—2*=""_5 Peptides Rennin is a milk protein digesting enzyme. Mucus lubricates the food and protects the inner lining of the stomach from the action of HCI. Sphincter muscles regulate the exit of food from stomach into intestine due to peristaltic waves of stomach. Mucus lubricates the food and protects the inner lining of the stomach from the action of HCl. Sphincter muscles regulate the exit of food from stomach into intestine due to peristaltic waves of stomach. © Small intestine: A tube about 6 meters long and about 2.5 cm wide. Much coiled and folded, it is present in the abdomen. Its three subdivisions are: > Duodenum: It is somewhat C shaped, short upper part of about 20-25 cm, next to stomach. Itreceives both bile and pancreatic juice. Jejunum: It is slightly longer part that connects duodenum to ileum and is about 2.4 m long. Heum: It is the longest coiled and twisted section of about 3. 6 m long. It joins to caecum of large intestine, ‘The small intestine is the site of the complete digestion of carbohydrates, proteins and fats. It receives the secretions of the liver and pancreas for digestion. How would it affect the digestion of proteins and carbohydrates in the duodenum of man, if the pancreatic duct is blocked? Explain. Explanation Duodenum is the region where the pancreatic juice secreted by the pancreas enters. The enzymes pancreatic amylase and trypsin help in the digestion of carbohydrates and proteins. Thus, if pancreatic duct is blocked these enzymes will not be secreted and complete digestion of proteins and carbohydrates will not occur, the digestion of carbohydrates and proteins get affected, © Large Intestine: It is shorter but wider than small intestine. Itis about 1.5 m long. Divided into three parts - > Caecum: Small blind pouch at the junction of small intestine and large intestine. A narrow worm-shaped tube projects from the caecum called the vermiform appendix. Colon: It has four parts termed ascending, transverse, descending and sigmoid colon. Rectum: It follows the colon. The rectum leads through long anal canal to the exterior through the anus, Anus is guarded by two circular muscles called anal sphincters. Important: The vermiform appendix is a vestigial (functionless) organ in humans but is large and functional in herbivorous mammals. (91Olympiads: Class 10 AL zn Digestive Glands Human digestive glands include salivary glands, liver and pancreas. They pour their secretions into the gut through their ducts. Salivary Glands: There are three pairs of salivary glands around our mouth cavity that secrete viscous fluid called saliva. Parotid glands: They are the largest salivary glands. They lie in front of the ears. Submaxillary glands: These lie at the junction of upper and lower jaw. Sublingual glands: These lie under the front part of the tongue. Functions of Saliva It makes the food soft, slippery and easy to swallow. It contains lysozyme which help in destroying the bacteria. Saliva helps in the digestion of food as it contains an enzyme salivary amylase also known as Ptyalin which digests the starch into maltose and dextrin, Liver It is the largest gland in our body located in upper right side of abdominal cavity. It produces bile juice. Bile plays an important role in the digestion of fats. Bile is stored in gall bladder located below the right lobe of liver. Pancreas ‘Small intestine ee Liverand pancreas Bile juice provides alkaline medium and emulsifies fats (conversion of larger fat globules into smaller fat droplets) but itis a non-enzymatic digestive juice, so has no chemical action on food. Salts present in bile juice help in emulsification of fats. Pancreas aE Ovo og OD)01 Marr OLY Hates Try Itis a heterocrine gland that lie partly behind the stomach, It acts as both, an endocrine gland as well as an exocrine gland. The exocrine part of pancreas secretes pancreatic juice that helps to digest carbohydrates, proteins and fats. The pancreatic juice converts carbohydrates into maltose and dextri Trolcneh cr cee se proteins into peptides and the fats to fatty acids and glycerol. [10]im ALLEN’ Biology a The Digestive Process heir Digestion involves two kinds of processes: Mechanical Process Mechanical process that includes cutting, grinding and swallowing the food that involves a > 7 breaking of food into smalll particles, and then pushing the food along the alimentary canal. Smaller particles expose greater surface area for action by enzymes. > Thelips hold the food within mouth and help in sucking and sipping of liquids. The teeth cut, tear and grind the food. > The tongue manipulates food while chewing, mixes saliva in it, rolls it into a ball termed bolus and helps in swallowing. > The oesophagus conducts the food (bolus) down into the stomach by a wave of constriction of the muscles. This wave of constriction is called peristalsis. own » The stomach churns the food mixing it with gastric juice secreted by gastric glands and thus produces a creamy chyme (partially digested food). Gastric juice comprises of HCl, mucus and inactive protein digesting enzyme called pepsinogen and prorennin. The peristaltic y. It movements keep pushing the food from stomach to the intestine and finally up to the rectum. gall > Intestinal glands release intestinal juices which contain enzymes that digest carbohydrates, proteins and fats into glucose, fructose, amino acid, fatty acids and glycerol. © Chemical Process: It includes the action of various enzymes on the ingested food thus breaking it into its simplest absorbable form. ere enor ae i Carbohydrate Digestion 22 Salivary amylase Salivary glands | Buccal cavity | Nearly Starch > Maltose + Dextrin a | Neutral { £ Pancreaticamylase Pancreas Small intestine Basic Starch 5 Maltose + Dextrin 2 | Maltase Intestinal Small intestine | Basic | Maltose —> Glucose + Glucose ules $8 slands 25 Protein Digestion tion | D Pepsin Gastricglands | Stomach Acidic Proteins -» Peptides + Proteases 2 \ieypsin Pancreas Small intestine Bai Proteins 5 Peptides | Peptidases and _ Intestinal Small intestine Basic Peptides - Dipeptides -» £4 Dipeptidases glands | Amino acids : 4 | FatDigestion | | ites, 3; Pancreatic Lipase | Pancreas | Small intestine Basic Fats > Fatty acids + glycerol 2 rins, $% Intestinal Lipase Intestinal | Smallintestine | Basie Fats Fatty acids + glycerol | 4 pore | T11Olympiads: Class 10 ALLEW Absorption of Nutrients: Very little absorption occurs in stomach (water, salts, alcohol). Some absorption occurs in large intestine. Absorption mainly occurs in small intestine. Small intestine is lined by epithelium which is specialised to absorb. It has mechanism to increase its absorbing surface area several times with the help of: Villi: They are transverse folds of intestinal wall that not only increase surface area but also reach deep into the lumen of intestine for absorption of digested food, Villi possess blood capillaries and lacteals (lymph vessels) for quick transport of absorbed food. Microvilli: Columnar cells of the intestinal epithelium have fine microscopic outgrowths called microvilli. Microvilli further Villi increase the surface area of epithelial cells Products absorbed into the blood capillaries of the villi are amino acids and monosaccharides (glucose, fructose, galactose). to the lacteals (lymph vessels) of the villi ar Products absorbed fatty acids and glycerol. Assimilation It is the incorporation of the absorbed food materials into the cells. The surplus amino acid gets deaminated in the liver by separation of amino group (NH). The amino group along with CO; is converted to urea and is excreted in the form of urine. Others are released into cells of body and transformed into proteins. Glucose is utilized for energy production, Excess of glucose is stored in liver and muscle cells in form of glycogen and rest is released to the body cells. This stored glycogen will be used first by a starving human, Excess fats are stored in liver, muscles and adipose tissue. Egestion The undigested and unabsorbed food then enters the large intestine. Colon absorbs the water and salts from the undigested food material. The undigested semi solid waste that passes into the rectum is called faeces. It is then removed through the anus at intervals by a process called Egestion or Defaecation. oli bacteria found in colon synthesize vitamin Bi, Bz, K. Digestion in Ruminants Grass eating animals like the cow, ox, buffalo and sheep swallow the food without chewing. After feeding, they bring the food from the stomach back into the mouth and chew it leisurely. This process is called rumination and such animals are called ruminants. [12] PrEN’ hol). e. mto and and roup form ist is nan, is the vaste m or 3 5 vand rants. ‘sine isi stato ‘Prone Wer 2122 Mele\ 37-yard. Mer OLY Mtn Tey rr ALLEN’ Biology Intestine aa Digestive system of ruminant The stomach of a ruminant is divided into four chambers - the rumen, reticulum, omasum. and abomasum, Among these, the rumen is the largest. The partially digested food in the rumen is called cud that enter the oesophagus via iculum, Symbiotic micro-organisms (bacteria) present in the rumen release cellulase enzyme that digest the cellulose. Abomasum is the "true stomach" w! In omasum absorption of fluid takes place, Digestion in ruminants is a good example of symbiosis. secretes acid & enzymes for digestion. [13]Olympiads: Class 10 ALLEN Autotrophio Heterotrophic Photoautotrophic (e.g. Green Plants) Chemoautotrophic'| 6CO, +12H,0 WRLC, H,,0, +6H,0 + 60, Methanogens, Seat Ht, hur bacteria) (ici 5 6CO, +12H,0 —————— Light energy C,H,,0, + 6H,0 + 60, Chlorophyll Ec Coy [Salivary Glands] [Liver | [Pancreas argelntestine | | [14]ALLEN Biology Multiple choice questions ‘The process in which water splits during photosynthesis is ~ (1) Photolysis (2) Hydrolysis (3) Plasmolysis (4) Hemolysis The oxygen in photosynthesis is released from - (1) Coz (3) Carbohydrate (2) H20 (4) Chlorophyll Dark reaction of photosynthesis occurs in- (1) Grana (3) Thylakoid (2) Stroma (4) Cytoplasm Photosynthesis proceeds in sequence of - (1) Dark phase and light phase (2) Light phase alone (3) Light phase and dark phase (4) Dark phase alone Carbon gets reduced during which event? (1) Light-dependent reactions (2) Light-independent reactions (3) Both (1) and (2) (4) None of the above Which one of the following is NOT required for photosynthesis to occur? (1) Coe 10. 14, 12. Light waves where photosynthesis is maximum are ~ (1) Orange (2) Green (3) Violet (4) Violet, blue and red Which one is an anabolic process? (1) Respiration (2) Digestion (3) Photosynthesis (4) ‘The carbohydrate reserve of plants is ~ (1) Starch Transpiration (2) Glycogen (3 (4) Cellulose. Stomata open when guard cells are ~ (1) Swollen (2) non-swollen (3) Flaccid (4) Both (2) and (3) Four students focused an epidermal peel of leaf under high power and made the following sketches. Which one is correctly sketched? jw & @ } _ g ° @ Mushroom, Rhizopus and Yeast are - (1) Chemosynthetic (2) 2 (2) Parasitic (3) ATP (3) Holozoic é (4) NADPH2 (4) Saprotrophs [15]Olympiads: Class 10 13, Which of the following is correct regarding the given Venn diagram? ‘Obtain food from other ae Obtain food possesses (,) from dead organisms [X) Nascular(Y) and decyin withoutkling\) “issues mater them (1) Xis Venus fly trap, Y is mistletoe. (2) Xis Cuscuta, Y is Monotropa (3) Xis mistletoe, Y is Cuscuta (4) Xis mistletoe, ¥ is mushroom. 14. Choose the forms in which most plants absorb nitrogen (@_ Proteins (ii) Nitrates (iii) Nitrites (iv) Atmospheric Nz (1) @and (i) (2) (ii) and (iti) (3) (iii) and (iv) (4) (i) and (iv) 18. The number of salivary glands present in human beings is ~ (1) S pairs (2) 4 pairs (3) 3 pairs (4) 2 pairs 16. _ Largest gland in the body is ~ (1) Liver (2) Pancreas (3) Gastric gland (4) Adrenal 17. Mode of nutrition in Amoeba is ~ (1) Saprotrophic (2) Parasitic (3) Holozoic (4) None of these 18. Which teeth in humans help in biting the food? (1) Canine (2) Incisor (3) Molar (4) Premolar 19, 20. 24. 22. 24. ALLEN Which substance of saliva destroys the harmful bacteria? (1) Amylase (2) Chyme (4) Hel Which statement is wrong about bile? (3) Lysozyme (1) Is necessary for fat digestion. (2) Is stored in the gall bladder. (3) Is digestion of sugar. (4) None of the above important only for normal Parotid salivary glands are present - (1) Below the tongue (2) Front of the ear (3) Below the eye orbit (4) None of the above Liver cells secrete ~ (1) Pepsin (2) Trypsin (3) Lipase (4) Bile which does not have enzyme Gastric juice is ~ (1) Acidic (2) Alkaline | (3) Neutral i (4) Slightly alkaline i The main function of intestinal villi is | to- | (1) Stimulate peristalsis | (2) Prevent peristalsis | (3) Provide large surface area for | absorption } (4) Distribute ' | uniformly digestive enzymes [16]mal ALLEN” 25. 26. 27. 28. 29. Biology Major function of HCl of gastric juice is - (1) Providing acidic medium for pepsin (2) Digestion of protein (3) Dissolve food (4) Facilitate absorption of food ‘The end product of fat digestion is/are - (1) Glucose (2) Fatty acids and glycerol (3) Amino acids (4) Dextrin ‘The action of bile can be called ~ (2) Oxidation (2) Emulsification (3) Reduction (4) Dehydrogenation Which set of juices is mixed with the food in small intestine? (1) Saliva, gastric juice, bile (2) Gastric juice, bile, pancreatic juice (8) Bile, pancreatic juice, intestinal juice (4) Bile, pancreatic juice and saliva A good source of lipase is ~ (1) Saliva (2) Gastric juice (3) Bile (4) Pancreatic juice Enzyme required for digestion of fat is ~ (2) Amylase (2) Trypsin (3) Pepsin (4) Lipase Ptyalin is an enzyme present in - (1) Gastric juice (2) Pancreatic juice (3) Intestinal juice (4) Saliva 32. 33. 34. 35. 36. 37. 38, In ruminants, symbiotic micro- organisms releasing cellulase are present in___ ofa stomach. (1) Omasum (3) Rumen (2) Abomasum (4) Reticulum Ptyalin, an enzyme in saliva works in ~ (1) Alkaline medium (2) Almost neutral medium (3) Acidic medium (4) Allmedium In pancreas, pancreatic juice and hormones are secreted by ~ (1) Same cells (2) Different Cells (3) Same cells at different times (4) None of these Amylase enzyme acts on the ~ (1) Starch (2) Protein (3) Fat (4) Cane sugar Trypsin is secreted by - (1) Pancreas (2) Stomach (3) Liver (4) Meum Dipeptides are broken down into amino acids in - (1) Buccal cavity (2) Stomach (3) Small intestine (4) Rectum Pryalin cannot work in stomach, j because it becomes ~ (1) Inactive due to HCL (2) Inactive due to Renin } (3) Inactive due to Pepsin | (4) None of these 17]Olympiads: Class 10 39, 40. 41. 42. 43. 44, 45. [18] Some proteolytic enzymes are ~ (1) Trypsin and Pepsin (2) Amylase and Lipase (3) Ptyalin and Lipase (4) Trypsin and Ptyalin Bacteria entering with contaminated food are killed in stomach by ~ (41) Pepsin (2) Rennin (3) Sodium bicarbonate (4) Hel Emulsification of fats by bile takes place in- (2) Mouth (3) Stomach Digestion of carbohydrates, proteins (2) Liver (4) Intestine and fats is completed in - (4) Stomach (2) Liver (3) Sinallintes (4) Large intestine Renin is found in - (1) Liver (2) Kidney (3) Pancreatic juice ine (4) Gastric juice in stomach Pancreatic juice takes part in digestion of- (1) Proteins, carbohydrate and fats (2) Proteins and fats (3) Protein, carbohydrate (4) Proteins only Amino acids are absorbed in - (1) Blood capillaries of villi (2) Wall of rectum (3) Lacteals and blood capillaries of vil (4) Lacteals of villi sell 46. Absorption of digested food chiefly occurs in ~ (1) Stomach (2) Colon (3) Small Intestine (4) Large Intestine 47. Herbivorous animals can digest cellulose because ~ (1) Their molar and premolar teeth can crush and grind the food, (2) Bacteria present in their stomach help in digestion of cellulose. (3) Liver secretes digestive enzyme for cellulose digestion. (4) Alimentary canal is very short. 48. Megha performs a test on starch's presence. She takes a bowl of rice, a piece of bread, a slice of lemon and a slice of cheese. She puts two drops of iodine solution on each food item and notes her observation by putting tick (1) if the colour of the iodine changes or cross (x) if the colour of iodine does not change with the given food items. What will be her observation? Ca erry oO v [@)V Vv Vv x Oly a x ee @ 4 Read the given statements. @ Cheese v x v | 49. Ingestion in Hydra occurs with the help of pseudopodia (ii) Bile juice is secreted by gall bladder and stored in liver. (iii) In humans, digestion of starch starts in the buccal cavity.- a ALLEN” Biology efly (iv) The outer covering of teeth is called (1) Stroma, grana enamel and is the hardest (2) Grana, thylakoid substance in the human body, (3) Grana, stroma (v) Omasum is the largest chamber of (4) Thylakoid, grana ruminant stomach where food is |53. Given below are the events of 7 stored, photosynthesis. Identify which of the Which of the above statements are following is/are not true and select the a incorrect? correct option. (1) (Gi) and(v) (D Absorption of light energy by ach (2) Gil) and (iv) chlorophyll. (3) (i, (i) and (iv) (i) The assimilatory power in the form for (4) (i), (i) and (iii) of NADPH and ATP are produced 50. Which reserve a starving man first during dark phase. consumes? (iii) Reduction of C02 to carbohydrates. rr (1) Starch (2) Protein (iv) Conversion of chemical energy to 7 (3) Glycogen (4) Vitamin radiant energy and splitting of : of 51. Thegiven figure is a demonstration of an water molecules into hydrogen and ind experiment to show that carbon dioxide oxygen. 0 is essential for photosynthesis. What is (1) @ and (Hi) or the substance 'X’, kept in watch-glass? (2) Gi) only not n (3) (li) and (iti) hat o (4) (ii) and (iv) he 54. — Identify the type of nutrition exhibited ral x by the given figure. | pod Set-A the ler ‘ch (1) Potassium hydroxide (2) Sodium bicarbonate (3) Potassium sulphate (4) Both (1) and (2) The light phase of photosynthesis ‘occurs in___ and dark phase occurs in (1) Autotrophic nutrition (2) Saprotrophic nutrition (3) Parasitic nutrition (4) Symbiotic nutrition (19)Olympiads: Class 10 55. 56. 57. (a) 3) oO) @ [20] Which cell organelle traps solar energy and helps in synthesizing food through photosynthesis? (1) Chloroplast (3) Cytoplasm (2) Mitochondria (4) Nucleus Which of the following statements support(s) the fact that the upper surface of a leaf is usually more green than the lower surface? (i) More chloroplasts are present on the upper surface to absorb more light. (ii) There are more stomata present on the upper surface than the lower surface. (iii) More sugar is formed on the lower surface, (iv) The lower surface of green leaf looks more green under the hot sun, (1) Gi)and (iii) (2) (i) only (3) (ii)and (iv) (4) (iii) only Match the column-I with column-II and select the correct option from the codes given below. “Salivary “sland Intestinal gland Pancreas | () Breaks down fats "Breaks down proteins into peptides (iii) Breaks down proteins ____ into amino acids (iv) Breaks down starch into sugar G) (@)-@, (b)-Gi), (Gti), (@)-(iv) (2) (@-Civ), &)-(ii), ()-Gi, ()-@) (3) (@)-Gi, (b)-Git), (6)-@, (@)-Civ) (4) (@)-Civ), (b)-Cid, (€)-iii), (@)-() ai) Liver 58. 59. ALLEN’ Refer to the given graph which shows the effect of pH on the activities of three enzymes, X, Y and Z. g 7 Yoa i & 3 g @ 2 10 «12 4 oye The three enzyme samples X, Y and Zare taken from which parts of the human entary canal? 5 (2) Duodenum Mouth Stomach (2) | Mouth ach__| Duodenum (3) Stomach) Ducdenum) Mouth (4) | Stomach Mouth Intesti The given graph shows the percentage of undigested carbohydrates, proteins and fats through successive parts of the human alimentary canal, Why does the percentage of undigested carbohydrates remain constant in part X? % of undigested & I . Buccal Cavity <= ‘Anus (1) Allthe starch has been digested and only other carbohydrates remain. (2) Protease at part X prevents the salivary amylase from acting on starch. (3) All the carbohydrates have been digested before reaching part X. (4) The acidic conditions of part X prevent salivary amylase from acting on starch, ; | i |three Zare man (nus land the arch. een t X rom 61. Hydrilla plant — Refer to the given diagram which shows various parts of human digestive system labelled as I, Il, Ill, IV and V. Identify the organs and select the incorrect statement regarding them. 1 (1) Organ-V is involved in storage of bile not its production. (2) Organ-II secretes digestive juice which contains. mucus, hydrochloric acid and digestive enzymes. (3) Organ-I is involved in the absorption of food. (4) Organ-IV is the largest gland of the body. Rohan set up an experiment as shown here. Select the correct statement regarding it. Bubbles of gas Inverted test tube 5 Beaker Inverted funnel ‘Water containing NaHCO3 Support to keep Funnel off bottom 62. Biology (1) NaHCOs present in water absorbs all the CO2 gas dissolved in water. (2) The bubbles produced in water within test tube are mainly of oxygen gas. (3) The plant present within the funnel cannot carry out photosynthesis due to non-availability of CO2. (4) This demonstrates that plants cannot experimental _set-up photosynthesize in. —_ water containing dissolved NaHCOs. Refer to given diagram of ruminant stomach and select the correct option regarding parts labelled as 1, 2, 3 and 4. Intestine os ~ >) secretes various digestive (2 enzymes for the digestion of various components of food. (2) 3 represents true stomach where complete digestion of food takes place. (3) Thepartially chewed food mixed with saliva is first sent to 4 for storage. (4) 1 harbour large population of anaerobic bacteria which help in digestion of cellulose present in food. [24]Olympiads: Class 10 63. Read the following statements and select the incorrect one. (1) The coloured largest gland, situated on liver is a reddish-brown the left side, just above the stomach. (2) Saliva contains enzymes to break down the insoluble starch of the food into soluble sugar. (3) There is a flap-like structure called epiglottis, which closes the wind pipe while eating. (4) Inruminants, the fourth chamber of stomach is abomasum which is called true stomach. 64. The given figure illustrates a section through a leaf, Which of the following results ifthe part labelled 'x' is removed? 1. Capture of light energy will not take place. Il. Production of carbohydrate will get affected. Ul, Production of protein will get affected, (1) Tand IM only (3) Land 1! only (2) Wand 1 only (4) Land mt 68. Garima took a plant and placed it in the dark for 24 hours to destarch its leaves, ALLEN After that she performed an activity as = fh shown here. leaf X 0 ww mp solution 2 o (iii) (She put one leaf (marked as X) in clean plastic bag containing soda lime and another leaf (marked as Y) in a clean plastic bag containing water. Then she left the plant in sunlight for 6 hours. (ii) She took out the leaves and boiled them in alcohol. (iii) She performed the iodine test on the leaves, Select the option with correct iodine test results and the conclusions of the activity. roars rns a ry corn oy crn oo) pce aa for 1 2 * Yes v | Yes 3a No |) Yes 4° No | ~~ No [22] I| ) in oda is Y) ning tin ‘iled : on test Hy } fy. Pa Hi ii ai i: pe ii lo as ae ii a af Biology nS ete [23]