Nutrition in Animals
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(b)
Class 7 Science · 28 questions · 28 with answers
Nutrition in Animals
(b)
Read carefully the terms given below. Which of the following set is the correct combination of organs that do not carry out any digestive functions?
(a) Oesophagus, Large Intestine, Rectum
The swallowed food moves downwards in the alimentary canal because of
(d) the contraction of muscles in the wall of food pipe. NUTRITION IN ANIMALS 7
The acid present in the stomach
(a) kills the harmful bacteria that may enter along with the food.
The finger-like outgrowths of Amoeba helps to ingest food. However, the finger-like outgrowths of human intestine helps
(c) absorb the digested food.
Read the following statements with reference to the villi of 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)
The false feet of Amoeba are used for
(c) capture of food and movement.
The enzymes present in the saliva convert
(b) starch into simple sugars.
Cud is the name given to the food of ruminants which is
(b) swallowed and partially digested.
Choose the correct order of terms that describes the process of nutrition in ruminants.
(a) swallowing → partial digestion → chewing of cud → complete digestion
Cellulose-rich food substances are good source of roughage in human beings because
(a) human beings do not have cellulose-digesting enzymes.
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.
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. NUTRITION IN ANIMALS 9
(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.
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
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?
With the help of different types of taste buds present in the tongue.
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.
Following statements describe the five steps in animal nutrition. Read each statement and give one word for each statement. Write the terms that describes each process.
(a) Transportation of absorbed food to different parts of 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.
Match the animals in Column I with their mode of feeding listed in Column II
(a) (iii); (b) (i); (c) (iv); (d) (ii) ANSWERS 101
Boojho took some grains of boiled rice in test tube ‘A’ and Paheli took boiled and chewed rice in 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.
In test tube ‘A’ – blue black colour because of presence of starch. In test tube ‘B’ – colour of iodine will not change because of digestion of starch into sugars.
‘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?
The food item would be fat because bile juice of the gall bladder helps in the digestion of fat. Removal of gall bladder leads to difficulty in digestion of fatty substances.
Match the organs in Column I with the words listed in Column II. NUTRITION IN ANIMALS 11
(a) (iv); (b) (v); (c) (i); (d) (iii); (e) (ii)
Ruminants such as cows and buffaloes swallow their food hurriedly and then sit restfully and chew their food. Can you reason why?
Hint (to digest the food completely.)
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.
Sometimes, when one eats hurriedly, talks or laughs while eating, the flap like valve, epiglottis closing the passage of windpipe remains open. The food may enter the wind pipe and coughing helps to clear it. LONG ANSWER QUESTIONS
Fill in the blanks using the words listed below. water, front, intestinal, salts, pseudopodia, back, vacuole
(a) The digestion of all food components is completed by the ____________ juice.
(b) Large intestine absorbs ___________ and some __________ from the undigested food.
(c) Tongue is attached at the _____________ to the floor of the mouth cavity and is free at the _____________.
(d) Amoeba pushes out _____________ around the food and traps it in a food _____________.
Label the below given Figure 2.1 as directed below in
This question refers to a figure in the original PDF.
(i) to
(ii) The piercing and tearing teeth as ‘B’
(iii) The grinding and chewing teeth as ‘C’ (iv) The grinding teeth present only in adult as ‘D’
(iv) and give the name of each type of teeth. Fig. 2.1 (i) The cutting and biting teeth as ‘A’
Read the following passage carefully and answer the questions that follows it. Bile juice is stored in a sac called, gall bladder, located near its organ of secretion, 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.
This question refers to a figure in the original PDF.
(a) Which organ secretes the bile juice?
(b) Why is digestion of fats difficult as compared to that of other nutrients?
(c) How does bile juice help in digestion of fat?
(d) Where is the digestion of fat completed? (e) Does bile juice digest fat completely? 28. Fig. 2.2 Label the following parts in Figure 2.2 and name them. (a) The largest gland in our body. (b) The organ where protein digestion starts. (c) The organ that releases digestive juice into the small intestine. (d) The organ where bile juice gets stored. NUTRITION IN ANIMALS 13
Open your mouth, look into a mirror and try to count the different types of teeth in your mouth. Compare them with Figure 2.3 on page 13 of your NCERT textbook. Record your observations in the table below:
This question refers to a figure in the original PDF.
Children have 28 teeth in their mouth. There are only four molars in each jaw and not six. Adults have six molars in each jaw.
Solve the crossword given as Figure 2.3. Fig. 2.3 Across Down 1. Cream-coloured digestive 2. Feeds with the help of gland pseudopodia 3. Undigested excretory solid 6. Total number of molars in residues one jaw of an adult 4. Organ that mixes saliva 8. Largest gland with the food 9. Watery secretion in the 5. Point of defecation mouth 7. Stored in gall bladder 11. A ruminant 10. Finger -like outgrowth in 12. Form of food chewed by the small intestine ruminants 13. Kind of taste buds 14. Kills bacteria in the stomach
This question refers to a figure in the original PDF.
ANSWERS 103