Nutrition in Animals Class 7 Science Extra Questions Very Short Answer Type Question 1. What is the total number of teeth in an adult human? In an adult human, there are total 32 teeth. Question 2. Name the parts of the alimentary canal where (a) water gets absorbed from undigested food (b) digested food gets absorbed (c) taste of the food is perceived (d) bile juice is produced [NCERT Exemplar] (a) large intestine (b) small intestine (c) tongue (d) liver Question 3. Identify the location of salivary gland. Salivary gland is present in the buccal cavity and it secretes saliva. Question 4. You were blindfolded and asked to identify the drinks provided in two different glasses. You could identify drink A as lime juice and B as bitter gourd juice. How could you do it inspite of being blindfolded? [NCERT Exemplar; HOTS] Inspite of being blindfolded, one could identify two different drinks with the help of taste buds present in the tongue. Question 5. We should not eat hurriedly. Give reason. We should not eat hurriedly because if we ingest food in hurry or we talk or laugh while eating we experience hiccups, coughing or choking sensation. Question 6. Name the secretions of stomach which digest food. The inner lining of stomach secretes mucous hydrochloric acid and digestive juices. Question 7. Explain the role of mucus secreted by stomach. The function of mucus is to protect the lining of stomach from the action of hydrochloric acid secreted by stomach lining. Question 8. The long structure of small intestine is accommodated in small space within our body. Comment. [HOTS] The small intestine is about 7.5 metre long It is accommodated in a coiled form inside our body. Question 9. Suggest the organ of digestive system where the digestive juices from liver and pancreas is poured. The digestive juices from liver and pancreas is poured into small intestine which helps in complete digestion and absorption of food. Question 10. From which organ of digestive system, the undigested faecal matter is removed? The undigested faecal matter is removed through the anus by the process called egestion. Question 11. Mention the position of the rumen in ruminants. The rumen is the sac-like structure which is present between small intestine and large intestine in ruminants. Question 12. What is assimilation? The process by which absorbed food is taken by body cells and is used for energy, growth and repair is called assimilation. Question 13. Describe alimentary canal briefly. Alimentary canal is the tube running from mouth to anus of human and animals here digestion and absorption of food take place. Question 14. Name the simple forms of carbohydrates, fats and proteins. The food components and their simple forms are carbohydrates (glucose), fatty (fats) acids and glycerol, proteins (amino acids). Question 15. Write the shape of stomach. The shape of stomach is like flattened U-shaped. Question 16. Discuss the role of hydrochloric acid secreted by gastric glands. It helps in the breakdown of food particles. It creates an acidic environment which facilitates the actionNutrition in Animals Class 7 Science Extra Questions Short Answer Type Question 1. With the help of labelled diagram show the gradual decay of tooth. Sweets and Tooth Decay The tooth is covered by white, hard outer covering of tooth called Enamel enamel below which dentine is present. It is similar to bone which Pulp cavity (with nerves and blood vessels) protects the pulp cavity having nerves and blood vessels. Bacteria are Gum present in our mouth but they are not harmful to us. However, if we do not clean our teeth and mouth after eating, many harmful bacteria also begin to live and grow in it. These bacteria breakdown the sugars present from the leftover food and release acids. The acids gradually damage the tooth. This is called tooth decay. Therefore, tooth decay is defined as the process of rotting of tooth and formation of cavity or holes in it which leads to the toothache. When the holes or cavity reaches to the pulp cavity, it causes pain. If these cavities are not treated on time it causes severe toothache and may result in tooth loss. Tooth decay can be prevented by adapting following measures. (i) One should rinse and clean its teeth thoroughly after every Pulp cavity meal. (ii) We should clean our teeth with the help of datun or brush Gradual decaying of human tooth and toothpaste, twice a day. (iii) We should use dental floss which is a special strong thread. It is moved between two teeth to take out trapped food particles. (iv) Dirty fingers or unwashed objects must be avoided to put in the mouth. (v) We should avoid the use of sweets, chocolates, toffees, ice-cream, etc. Much use of cold drink should also be avoided.” Question 2. Name the various components of food and their simpler forms. The various components of food and their simpler forms areComponents of foodSimpler formCarbohydrateGlucoseFatsFatty acids and glycerolProteinsAmino acidsVitaminsVitaminsMinerals and waterMinerals and water Question 3. ‘A’ got her gall bladder removed surgically as she was diagnosed with stones in her gall bladder. After the surgery, she faced problems in digestion of certain food items when consumed in bulk. Can you tell which kind of food items would they be and why? [NCERT Exemplar; HOTS] After surgical removal of gall bladder, ‘A’ would face problems in digestion of fat and fatty substances when consumed in bulk. This is because the bile juice stored in the gall bladder helps in digestion of fats. Question 4. Discuss the various associated glands of digestive system and their role in digestion. The various associated glands of digestive system and their role in digestion are as followsSalivary gland digestion of starch in mouth.Liver secretes bile juices which help in the digestion of fats.Pancreas secretes pancreatic juices which act on carbohydrate, fats and proteins and change them into simpler compounds. Question 5. Boojho took some grains of boiled rice in test tube ‘A’ and Paheli took boiled and chewed rice in test tube ‘S’. Both of them poured 1-2 drops of iodine solution into the test tube and observed the colour change. What colour change would they have observed? Give reasons for your [NCERT Exemplar; HOTS] In test tube A, blue black colour appeared because of presence of starch. In test tube 6, colour of iodine will not change because of digestion of starch into sugars by the action of saliva in our mouth. Question 6. Mention the different steps of nutrition in animals. Question 7. List the preventive measures that one should adopt for avoiding tooth decay. Sweets and Tooth Decay The tooth is covered by white, hard outer covering of tooth called Enamel enamel below which dentine is present. It is similar to bone which Pulp cavity (with nerves and blood vessels) protects the pulp cavity having nerves and blood vessels. Bacteria are Gum present in our mouth but they are not harmful to us. However, if we do not clean our teeth and mouth after eating, many harmful bacteria also begin to live and grow in it. These bacteria breakdown the sugars present from the leftover food and release acids. The acids gradually damage the tooth. This is called tooth decay. Therefore, tooth decay is defined as the process of rotting of tooth and formation of cavity or holes in it which leads to the toothache. When the holes or cavity reaches to the pulp cavity, it causes pain. If these cavities are not treated on time it causes severe toothache and may result in tooth loss. Tooth decay can be prevented by adapting following measures. (i) One should rinse and clean its teeth thoroughly after every Pulp cavity meal. (ii) We should clean our teeth with the help of datun or brush Gradual decaying of human tooth and toothpaste, twice a day. (iii) We should use dental floss which is a special strong thread. It is moved between two teeth to take out trapped food particles. (iv) Dirty fingers or unwashed objects must be avoided to put in the mouth. (v) We should avoid the use of sweets, chocolates, toffees, ice-cream, etc. Much use of cold drink should also be avoided.” Question 8. Write the difference between milk teeth and permanent teeth. The difference between milk teeth and permanent teeth areMilk teethPermanent teethThey grow during infancy, i.e. when one is small baby.They grow at the age of 6-8 years.They are also called as temporary teeth because these are lost at the age of 6-8 years.They do not fall till the old age.They can be replaced by permanent teeth.If these teeth fall down no new teeth arises on its place. Question 9. Complete the following table, from the options given below: (Scraping, chewing, siphoning, capturing and swallowing, sponging, sucking, etc.)Name of animalKind of animalMode of feedingSnail Ant Eagle Humming bird Lice Mosquito Butterfly Housefly The complete table isName of animalKind of foodMode of feedingSnailLeaves and insectsScrapingAntFood particlesChewingEagleSmall animalsCapturing and swallowingHumming birdNectar of flowerSuckingLiceBloodSuckingMosquitoBloodSuckingButterflyNactar of flowerSiphoningHouseflyAll most everythingSponging Question 10. Briefly describe the mechanism of producing hiccups while we take food in hurry. Question 11. Boojho and Paheli were eating their food hurriedly so that they could go out and play during the recess. Suddenly, Boojho started coughing violently. Think of th