Nutrition in Animals: Class 7 Science Q&A
32 free answers on Nutrition in Animals (Science) for Class 7 students, across CBSE, ICSE and State boards.
Question & Answer
Questions
- ScienceClass 7CBSE
Read the following passage carefully and answer the questions that follow it. Bile juice is stored in a sac called the gallbladder, located near its organ of secretion, the liver. The gall bladder releases the bile juice into the small intestine whenever food reaches there. Though bile juice is devoid of any digestive enzymes, it is required for the digestion of fats. The fats cannot be digested easily because they are insoluble in water and are present as large globules. Bile juice breaks down big fat droplets into smaller droplets. These are then easily digested by the enzymes released from the pancreas. (a) Which organ secretes the bile juice? (b) Why is the digestion of fats difficult as compared to that of other nutrients? (c) How does bile juice help in the digestion of fat? (d) Where is the digestion of fat completed? (e) Does bile juice digest fat completely?
Soln: (a) Liver (b) Insolubility of fat in water. (c) Breaks down big fat droplets into smaller droplets. (d) Small intestine (e) No
- ScienceClass 7CBSE
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 the reasons why he was coughing and discuss with your friends.
Soln: Sometimes, when one eats hurriedly, talks or laughs while eating, the flap-like valve, epiglottis, closing the passage of the windpipe, remains open. The food may enter the windpipe and coughing helps to clear it.
- ScienceClass 7CBSE
Ruminants such as cows and buffaloes swallow their food hurriedly and then sit restfully and chew their food. Can you reason why?
Soln: To digest the food completely, ruminants keep the food as cuds.
- ScienceClass 7CBSE
‘A’ got her gallbladder removed surgically as she was diagnosed with stones in her gallbladder. After the surgery, she faced problems in the digestion of certain food items when consumed in bulk. Can you tell which kind of food items would they be and why?
Soln: Those foods will be fats because of bile juice present in the gall bladder helps in the digestion of fat. Removal of gall bladder makes it hard to digest the fat.
- ScienceClass 7CBSE
Boojho took some grains of boiled rice in a test tube ‘A’, and Paheli took boiled and chewed rice in a test tube ‘B’. 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 answer.
Soln: In test-tube A colour of iodine changes to blue-black because of the reaction of iodine with starch. In test-tube B colour will not change because salivary amylase acts on starch while chewing, reducing it to simpler sugars.
- ScienceClass 7CBSE
Following statements describe the five steps in animal nutrition. Read each statement and give one word for each statement. Write the terms that describe each process. (a) Transportation of absorbed food to different parts of the body and their utilisation. (b) Breaking of complex food substances into simpler and soluble substances. (c) Removal of undigested and unabsorbed solid residues of food from the body. (d) Taking food into the body. (e) Transport of digested and soluble food from the intestine to blood vessels.
Soln: (a) Assimilation (b) Digestion (c) Egestion (d) Ingestion (e) Absorption
- ScienceClass 7CBSE
Q. Fill in the blanks with suitable words: (a) The alimentary canal stretches from to. (b) Teeth are rooted in separate in between the. (c) Digestion of food starts in and gets completed in. (d) is the largest gland in the human body.
Soln: The alimentary canal stretches from Mouth to Anus. Teeth are rooted in separate Sockets in between the Gums. Digestion of food starts in the Buccal cavity and gets completed in Small Intestine. The liver is the largest gland in the human body.
- ScienceClass 7CBSE
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 in spite of being blindfolded?
Soln: We can identify the juices with the help of different taste buds present in the tongue.
- ScienceClass 7CBSE
Choose the odd one out from each group and give reasons. (i) liver, salivary gland, starch, gall bladder (ii) stomach, liver, pancreas, salivary gland (iii) tongue, absorption, taste, swallow (iv) oesophagus, small intestine, large intestine, rectum
Soln: The answer is Starch because starch is a carbohydrate, whereas the liver, salivary gland and gall bladder are the glands. The answer is the stomach because others are digestive glands Absorption is the answer because tongue, swallow and taste are related to the buccal cavity but not absorption. The small intestine is the answer because the oesophagus, large intestine and rectum will not take part in digestion, whereas the sma
- ScienceClass 7CBSE
Mark the following statements as True or False. If false, write the correct statements. (a) Tongue is attached to the roof of the mouth cavity at the back. (b) The large intestine is longer and wider than the small intestine of the human alimentary canal. (c) Mucus protects the stomach lining from damage. (d) All heterotrophs have a similar basic process of nutrition.
Soln: False – The tongue is attached to the floor of the mouth cavity at the back. False – The large intestine is shorter and wider than the small intestine of the human alimentary canal. True True
- ScienceClass 7CBSE
Name the parts of the alimentary canal where (i) water gets absorbed from undigested food. (ii) digested food gets absorbed. (iii) taste of the food is perceived. (iv) bile juice is produced.
Soln: (i) Large intestine (ii) Small intestine (iii) Tongue (iv) Liver
- ScienceClass 7CBSE
Cellulose-rich food substances are a good source of roughage in human beings because (a) human beings do not have cellulose-digesting enzymes. (b) cellulose gets absorbed in the human blood and converts into fibres. (c) the cellulose-digesting bacteria convert cellulose into fibres. (d) cellulose breaks down into smaller components which are egested as roughage.
Soln: The answer is (a) human beings do not have cellulose-digesting enzymes.
- ScienceClass 7CBSE
Choose the correct order of terms that describes the process of nutrition in ruminants. (a) swallowing → partial digestion → chewing of cud → complete digestion (b) chewing of cud → swallowing → partial digestion → complete digestion (c) chewing of cud → swallowing → mixing with digestive juices → digestion (d) swallowing → chewing and mixing → partial digestion → complete digestion
Soln: The answer is (a) swallowing → partial digestion → chewing of cud → complete digestion
- ScienceClass 7CBSE
Cud is the name given to the food of ruminants which is (a) swallowed and undigested. (b) swallowed and partially digested. (c) properly chewed and partially digested. (d) properly chewed and completely digested.
Soln: The answer is (b) swallowed and partially digested. Explanation: Ruminants quickly swallow the grass and store it in a part of the stomach called the rumen. Here the food gets partially digested and is called cud. But later, the cud returns to the mouth in small lumps, and the animal chews it. This process is called rumination.
- ScienceClass 7CBSE
The enzymes present in the saliva convert (a) fats into fatty acids and glycerol. (b) starch into simple sugars. (c) proteins into amino acids. (d) complex sugars into simple sugars.
Soln: The answer is (b) starch into simple sugars. Explanation: Saliva consists of salivary amylase enzyme, which breaks starch into simple sugar, which is further digested by enzymes in the stomach and small intestine.
- ScienceClass 7CBSE
The false feet of Amoeba are used for (a) movement only. (b) the capture of food only. (c) the capture of food and movement. (d) exchange of gases only.
Soln: The answer is (c) capture of food and movement. Explanation: Amoeba constantly changes their shape and position. It pushes out one, or more finger-like projections, called pseudopodia or false feet, for movement and capture of food. Amoeba feeds on some microscopic organisms. When it senses food, it pushes out pseudopodia around the food particle and engulfs it.
- ScienceClass 7CBSE
Read the following statements with reference to the villi of the small intestine. (i) They have very thin walls. (ii) They have a network of thin and small blood vessels close to the surface. (iii) They have small pores through which food can easily pass. (iv) They are finger-like projections. Identify those statements which enable the villi to absorb digested food. (a) (i), (ii) and (iv) (b) (ii), (iii) and (iv) (c) (iii) and (iv) (d) (i) and (iv)
Soln: Answer is (a) (i), (ii) and (iv) Explanation: The inner walls of the small intestine have thousands of finger-like outgrowths called villi (singular villus). Villi increase the surface area for absorption of the digested food. Each villus has a network of thin and small blood vessels close to its surface. The surface of the villi absorbs the digested food materials. The absorbed substances are transported via the
- ScienceClass 7CBSE
The finger-like outgrowths of Amoeba help to ingest food. However, the finger-like outgrowths of the human intestine help to (a) digest the fatty food substances. (b) make the food soluble. (c) absorb the digested food. (d) absorb undigested food.
Soln: The answer is (c) absorb the digested food. Explanation: Fingerlike projection is present in the small intestine, and they are called Villi. Villi absorb nutrients from digested food by increasing the space of the small intestine.
- ScienceClass 7CBSE
The acid present in the stomach (a) kills the harmful bacteria that may enter along with the food. (b) protects the stomach lining from harmful substances. (c) digests starch into simpler sugars. (d) makes the medium alkaline.
Soln: The answer is (a) kills the harmful bacteria that may enter along with the food. Explanation: The stomach consists of Hydrochloric acid, which kills the bacteria that enter through food. Thus stomach acid is helping in protecting us from harmful bacteria.
- ScienceClass 7CBSE
The swallowed food moves downwards in the alimentary canal because of (a) force provided by the muscular tongue. (b) the flow of water taken with the food. (c) gravitational pull. (d) the contraction of muscles in the wall of the food pipe.
Soln: The answer is (d) the contraction of muscles in the wall of the food pipe. Explanation: Muscles of the Esophagus push food down by the movement of the wall of the food pipe. Actually, this movement takes place throughout the alimentary canal and pushes the food downwards.