E. Short Answer Type-I Questions: 1. What is the function of saliva? Ans: The digestive functions of saliva include moistening food, and helping to create a food bolus, so it can be swallowed easily. Saliva contains the enzyme amylase, also called ptyalin, which is capable of breaking down starch into simpler sugars such as maltose and dextrin that can be further broken down in the small intestine 2. What is ingestion? Ans: The process of taking food inside our mouth is known as ingestion. 3. What is chyme? Ans: Partially digested food formed by the action of gastric juice in the stomach is called as chime. 4. What happens to the undigested food in the body? Ans: The undigested food passes to large intestine.Some water is absorbed and the semi solid waste (feces) is egested through anus. 5. What do you understand by the term assimilation? Ans: The process of producing energy from the absorbed food is known as assimilation 6. Where is liver located? Give its function. Ans:liver lies in front of stomach. Liver secrate bile that is stored in gall bladder. It make the digestion of fat faster. Note: Bile juice contains no digestive enzymes, yet it is important for digestion. Bile juice has bile pigments such as bilirubin and biliverdin. These break down large fat globules into smaller globules so that the pancreatic enzymes can easily act on them. This process is known as emulsification of fats. F. Short Answer Type-Il Questions: 1. Why we cannot breathe and swallow at the same time? Ans: Every time we swallow, the epiglottis closes the wind pipe .If we breathe and swallow at the same time, food or water enters wind pipe and we chock and cough. 2. In what substances carbohydrates, proteins and fats get converted into after digestion? Ans: in small intestine Carbohydrates get converted into sugars. Proteins get converted into amino acids. Fats get converted into fatty acids and glycerol. 3. What are the functions performed by tongue? Ans: tongue helps in process of chewing by pushing the food towards the teeth. It also help to mix the food with saliva. 4. Which part of the alimentary canals involved in (a) chewing of food (b) killing of bacteria (C) absorption of food (d) formation of faeces? Ans: (a) chewing of food – Mouth (b) killing of bacteria – stomach (C) absorption of food – small intestine (d) formation of faeces – large intestine 5. Different types of teeth in our jaws have different functions, but they all work together to chew the food. Ans: Different types of teeth in our jaws have different functions (i) Incisors :- They help us in biting and cutting the food. (ii) Canines : - They help us in piercing and tearing the pieces of meat. (iii) Premolars:- They assist the molars by holding the food with their cusps and also crushing them. (iv) Molars : - They help us in chewing and grinding the food so that it can be swallowed easily. (b) What do we learn from our teeth that have different functions? Ans: If we work united we will do any impossible work . G. Long Answer Questions: 1. Briefly describe nutrition in Amoeba with the help of diagrams. Ans: Amoeba takes in food by forming temporary finger-like projections called pseudopodia. The pseudopodia fuse over the food particle forming a food vacuole. The digestive enzymes from the surrounding cytoplasm enter into the food vacuole and breakdown the food into small, water soluble molecules by chemical reactions. The digested food from the food vacuole spreads into the whole of Amoeba cell and gets absorbed in the cytoplasm. A part of absorbed food is used to obtain energy through respiration and some is used for the growth of Amoeba cell. The undigested part of the food is moved to the surface of Amoeba cell and egested (thrown out) by the rupture of cell membrane. 2. Describe the process of digestion in ruminants. Ans: The stomach of a ruminant is divided into four chambers. As soon as the ruminant swallows the food, it enters the first chamber called rumen where it gets partially digested (converted to cud). From here, the food enters the second chamber from where it again reaches the mouth for rumination, which is thorough chewing. The food is again swallowed, and now it enters the third and the fourth chamber for digestion. From here, it enters the small intestine for the absorption of nutrients. 3. What are liver and pancreas? Write their functions in detail. Ans: liver and pancreas are organ that help in digestion of food. Live produce bile juice that breaks down fats and stores some vitamins and minerals. The pancreas has two main functions: an exocrine function that helps in digestion and an endocrine function that regulates blood sugar. Note: Liver is the largest gland of the body. It is a reddish-brown gland situated on the right side of the upper part of the Abdomen. Functions of liver are as follows: (i) To secrete bile juice which helps in the emulsification of fats present in the food. (ii) Detoxification- Conversion of toxic substances into non-toxic forms like conversion of ammonia to urea which gets excreted in the urine. (iii) Clearing the blood from drugs and other harmful substances. (iv) Conversion of excess glucose into glycogen for storage (glycogen can later be converted back to glucose to energy when body is in short of nutrients) Pancreas is a organ located in the upper abdomen and adjacent to the small intestine. It performs two main kind of functions in the body: (i) Exocrine function: It helps in the digestion of food. It produces various enzymes such as amylase, lipase and trypsin which helps to digest carbohydrate, fats and proteins respectively. (ii) Endocrine function: It produces hormonal insulin and glucagon which regulate the level of sugar present in the blood H. HOTS (Higher Order Thinking Skills) Questions: 1. The bacteria present on uncleaned teeth convert the sugar in food into a substance 'X' which causes tooth decay. Name the substance 'X'. Which part of the teeth does it affect? Ans: Substance X is lactic acid which is formed in the mouth after we eat food containing sugar. it affect enamel. [ Note : Lactic acid lowers the pH in the mouth making it acidic. Our tooth enamel is made up of calcium phosphate, which is the hardest material in our body, but even it starts getting corroded when the pH in the mouth is lower than 5.5(Acidic)] 2. How is ruminant's stomach different from humans? Ans: The stomach of a ruminant is divided into four chambers they are rumen, reticulum, omasum, and abomasum. Human stomach is a single organ. For more books and full solution visit 7th Science
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Class7 Chapter 01 Nutrition in plants and Animals Cordova Science Exercise A (Tick) the correct options: 1. Rhizobium bacteria live in the root nodules of plant (a) wheat (b) rice (c) barley (d) peaÖ 2. Plants store food as (a) cellulose (b) sugar (c) glucose (d) starchÖ 3. Which of the following is an insectivorous plant? (a) Cucuta (b) DroseraÖ (c) mistletoe (d) lichen 4. The mode of nutrition shown by Cuscuta is (a) parasiticÖ (b) symbiotic (c) saprophyte (d) autotrophic 5. On adding iodine solution, starch (a) turns blue blackÖ (b) turns green (C) remains colourless (d) turns red 6. We keep healthy potted plant in a dark room for some days to the leaves (a) decolourise (b) defragment (c) destarchÖ (d) deprotein 7. The portion of leaf that is not exposed to sunlight, will not make (a) fats (b) protein (c) glucose Ö (d) starch B.Fill in the blanks: 1. Rhizobium bacteria provide --nitrogen---- to the leguminous plants. 2. Green plants make their food by the process of photosynthesis. 3. Stomata are surrounded by guard cells. 4. Cuscuta is a -Total--- parasite. 5. The roots of saprophytes contain organisms called ….symbionts C. Very Short Answer Questions: 1. Name any two heterotrophs. Ans: Animals,Mushroom 2. Name any two insectivorous plants. Ans: Venus flytrap, pitcher plants, butterworts, sundews 3. Name the pores through which leaves exchange gases. Ans: Stomata 4. Name one plant in which photosynthesis occurs in plant part other than leaves. Name the plant part. Ans: cactus in it's stem 5. What are the two main modes of nutrition in plants? Ans: Autotropic and heterotrophic 6. Name the green pigment present in the leaves. Ans: Chlorophyll D. Short Answer Type-l Questions: 1. What are autotrophs? Ans: Organism prepare own food like green plants 2. Why is Cuscuta called parasite? Ans: Cuscuta is called parasite as it draw nutrition from host. 3. In which form, do plants need nitrogen? Ans: Plants absorb nitrogen from the soil in the form of nitrate (NO3−) and ammonium (NH4+) 4. Why are leaves of a plant green in colour? Ans: leaves of a plant are green in colour due to presence of chlorophyll. 5. Why do some plants feed on insects? Ans: some plants feed on insects to get nitrogenous compound from which they make protein 6. Define photosynthesis. Ans: Photosynthesis is the food making process of green plant using CO2 and water in the presence of sunlight E. Short Answer Type-ll Questions: 1. How can we decolorized a leaf? What will you conclude when white patches do not turn blue black adding iodine solution? Ans: Leaf of green plant heated in a test tube containing alcohol in water bath to decolorize. if white patches do not turn blue black adding iodine solution showing absence of starch 2. What is saprotrophic mode of nutrition? Give one example. Ans: The mode of nutrition in which organism derive nutrients from dead and decaying organic matter. Eg. Mushroom. Saprophytes breakdown organic matter by secreting digestive juice into it. Then they absorb what they need from the digested matter. 3. How does the pitcher plant catch its food? Ans : Pitcher plants have leaves that look like pitchers. The lid of the pitcher closes when an insect lands on the pitcher. The trapped insect slides down the wall of the pitcher and is digested inside it. 4. Algae and fungi live together in lichens. (a) What is this association called? (b) What value can we learn from this association in nature? Ans: The fungus provides minerals and water to the alga. The alga supplies the fungus with food that it manufactures. (a) Symbiotic relationship (b) We live with other in mutual benefit take help and give help. 5. Discuss the importance of photosynthesis. Ans: Photosynthesis helps green plant to prepare glucose. Photosynthesis use CO2 and release O2 and thus balance the oxygen and carbon dioxide level in atmosphere. Water vapor released during photosynthesis also help in formation of cloud and bring rain. F. Long Answer Questions: 1. Write an experiment to show that sunlight is necessary for photosynthesis. Ans: cover a part of a leaf of a potted plant with black paper. Use paper clips to fix the paper on both sides of the leaf Make sure the plant get enough sunlight Pluck the leaf and take off the paper after two days. Heat the leaf in alcohol, as in the previous activity, and test for starch. Only the part of the leaf which was exposed to sunlight will turn blue-black. This shows that sunlight is necessary for photosynthesis. 2. How do Rhizobium bacteria and leguminous plants help each other in survival?
Ans: Plant provide shelter to Rhizobium bacteria and Rhizobium bacteria provide nitrogenous compound that plants required to make plants protein. G. HOTS (Higher Order Thinking Skills) Questions: 1. What will happen if plant leaves are devoid of stomata? Ans: if plant leaves are devoid of stomata there is no exchange of gases like O2 and CO2 . Plants cannot perform photosynthesis 2. What will happen if all the plants disappear from the earth? Ans: Food chain unbalance and no life exist. For more chapter visit 7th science Using direct and indirect variation method solve this exercise in just a min.(By Jsunil Sir 7th CBSE Maths SA-I [Link] Integers Fractions & decimals Data handling Simple equations Lines & angles The triangle & its properties Congruence of triangles 7th CBSE Maths SA-II [Link] Comparing quantities Rational numbers Practical geometry Perimeter & area Algebraic expressions Exponent & powers Symmetry Visualizing solid figures Above Post related to
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