class 7 science important qustion chapter 1

 

• Nutrition in Plants

1. Organisms which prepare food for themselves using simple naturally available raw materials are referred to as
   • (a) heterotrophs
   • (b) autotrophs
   • (c) parasites
   • (d) saprophytes
2. In the absence of which of the following will photosynthesis not occur in leaves?
   • (a) Guard cells
   • (b) Chlorophyll
   • (c) Vacuole
   • (d) Space between cells
3. Which of the following statements is/are correct?
   (i) All green plants can prepare their own food.
   (ii) Most animals are autotrophs.
   (iii) Carbon dioxide is not required for photosynthesis.
   (iv) Oxygen is liberated during photosynthesis.
   Choose the correct answer from the options below:
   • (a) (i) and (iv)
   • (b) (ii) only
   • (c) (ii) and (iii)
   • (d) (i) and (ii)
4. Pitcher plant traps insects because it
   • (a) is a heterotroph.
   • (b) grows in soils which lack in nitrogen.
   • (c) does not have chlorophyll.
   • (d) has a digestive system like human beings.
5. The term that is used for the mode of nutrition in yeast, mushroom and bread-mould is
   • (a) autotrophic
   • (b) insectivorous
   • (c) saprophytic
   • (d) parasitic
6. When we observe the lower surface of a leaf through a magnifying lens we see numerous small openings. Which of the following is the term given to such openings?
   • (a) Stomata
   • (b) Lamina
   • (c) Midrib
   • (d) Veins
7. Two organisms are good friends and live together. One provides shelter, water, and nutrients while the other prepares and provides food. Such an association of organisms is termed as
   • (a) saprophyte
   • (b) parasite
   • (c) autotroph
   • (d) symbiosis
8. Which of the following raw material is available in the air for photosynthesis?
   • (a) Oxygen
   • (b) Carbon dioxide
   • (c) Nitrogen
   • (d) Hydrogen

Very Short Answer Type Questions

1. Potato and ginger are both underground parts that store food. Where is the food prepared in these plants?

Short Answer Type Questions

1. A goat eats away all the leaves of a small plant (balsam). However, in a few days, new leaves could be seen sprouting in the plant again. How did the plant survive without leaves?
2. Unscramble the following to form terms related to modes of nutrition.
   (i) RASPAEIT
   (ii) ROPEHYTSAP
   (iii) TOROPHAUT
   (iv) SIBIOMSYS
3. Nitrogen is an essential nutrient for plant growth. But farmers who cultivate pulse crops like green gram, bengal gram, black gram, etc. do not apply nitrogenous fertilizers during cultivation. Why?
4. Wheat dough if left in the open, after a few days, starts to emit a foul smell and becomes unfit for use. Give reason.
5. Sunlight, chlorophyll, carbon dioxide, water and minerals are raw materials essential for photosynthesis. Do you know where they are available? Fill in the blanks with the appropriate raw materials.
   (a) Available in the plant : _______________
   (b) Available in the soil : _______________, _______________
   (c) Available in the air : _______________
   (d) Available during day : _______________
6. Observe the diagram given as Figure 1.1 and label the following terms given in the box.
   stomatal opening, guard cell
   

Long Answer Type Questions

1. Match the organisms given in Column I with their mode of nutrition given in Column II.
   
2. Wild animals like tiger, wolf, lion and leopard do not eat plants. Does this mean that they can survive without plants? Can you provide a suitable explanation?
3. Fill in the blanks of the paragraph given below with the words provided in the box.
   chlorophyll, energy, food, carbon dioxide, water, photosynthesis
   Note: A word can be used more than once.
5. Spot as many organisms as possible in the puzzle given as Figure 1.2 by encircling them as shown. Write the names on a sheet of paper and categorise them into autotrophs and heterotrophs. Classify the heterotrophs into herbivores, carnivores, omnivores and saprophytes.
   
6. Can you give me a name?
   Solve each of the following riddles by writing the name of the organism and its mode of nutrition. One riddle is solved to help you.
   • (a) I am tall but I cannot move. I am green and can prepare my own food. tree, autotroph
   • (b) I live in water; people keep me in an aquarium and feed me. ___________, ______________
   • (c) I am small and I can fly. I disturb your sleep, bite you and suck your blood which is my food. _______________, _______________
   • (d) I am white and soft. I grow well in the rainy season. Children pluck me from the ground and admire me. I absorb nutrients from decomposed dead parts of plants and animals in the soil. ______________, _________________.

Answers to Multiple Choice Questions

1. (b)	2. (b)	3. (a)	4. (b)
5. (c)	6. (a)	7. (d)	8. (b) Given below from (i) to (iv) are some food items. (i) Boiled and mashed potato (ii) Glucose solution (iii) A slice of bread (iv) Mustard oil Which of the above will give blue-black colour when tested with iodine? (a) (i) and (ii) (b) (i) and (iii) (c) (ii) and (iii) (d) (iii) and (iv) Which of the following pair of teeth differ in structure but are similar in function? (a) canines and incisors. (b) molars and premolars. (c) incisors and molars. (d) premolars and canines. 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 (b) Buccal cavity, Oesophagus, Rectum (c) Buccal cavity, Oesophagus, Large Intestine (d) Small Intestine, Large Intestine, Rectum 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 food pipe. 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. The finger-like outgrowths of Amoeba helps to ingest food. However, the finger-like outgrowths of human intestine helps to (a) digest the fatty food substances. (b) make the food soluble. (c) absorb the digested food. (d) absorb the undigested 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) (b) (ii), (iii) and (iv) (c) (iii) and (iv) (d) (i) and (iv) The false feet of Amoeba are used for (a) movement only. (b) capture of food only. (c) capture of food and movement. (d) exchange of gases only. 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. 10. 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. 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 Cellulose-rich food substances are 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. Very Short Answer Type Questions 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. (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? 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. Short Answer Type Questions Match the animals in Column I with their mode of feeding listed in Column II 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. ‘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? Match the organs in Column I with the words listed in Column II. Ruminants such as cows and buffaloes swallow their food hurriedly and then sit restfully and chew their food. Can you reason why? 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. Long Answer Type 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 (i) to (iv) and give the name of each type of teeth. (i) The cutting and biting teeth as ‘A’ (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’ 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. (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? 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. 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: (a) Did you observe any difference in the number of teeth? If yes, could you identify which type of teeth showed the difference? (b) Compare the number and type of teeth in an adult (say your parents or cousins who have reached the age of 25–30 or more). Note your observation. Solve the crossword given as Figure 2.3. « Previous Next » Answers to Multiple Choice Questions 1. (b) 2. (b) 3. (a) 4. (d) 5. (a) 6. (c) 7. (a) 8. (c) 9. (b) 10. (b) 11. (a) 12. (a) The rearing of silkworms for obtaining silk is called (a) cocoon (b) silk (c) sericulture (d) silviculture Which of the following is not a type of silk? (a) Mulberry silk (b) Tassar silk (c) Mooga silk (d) Moth silk Paheli wanted to buy a gift made of animal fibre obtained without killing the animal. Which of the following would be the right gift for her to buy? (a) Woollen shawl (b) Silk scarf (c) Animal fur cap (d) Leather jacket Silk fibre is obtained from (a) fleece of sheep (b) cotton ball (c) cocoon (d) shiny jute stalk Wool fibre cannot be obtained from which of the following? (a) Goat (b) Llama (c) Alpaca (d) Moth Selective breeding is a process of (a) selecting the offsprings with desired properties. (b) selecting the parents with desired properties. (c) selecting an area for breeding. (d) selecting fine hair for good quality wool. The general process that takes place at a sheep shearing shed is (a) removal of fleece. (b) separating hair of different textures. (c) washing of sheep fibre to remove grease. (d) rolling of sheep fibre into yarn. The term sericulture is used for (a) culture of bacteria. (b) rearing of silkworm. (c) making silk fabric from silk yarn. (d) production of sarees. Reeling of silk is (a) a process of making silk reels. (b) spinning of silk fibres. (c) weaving of silk cloth. (d) the process of taking silk threads from cocoon. Silkworms secrete fibre made of (a) fat (b) cellulose (c) protein (d) nylon Very Short Answer Type Questions Fill in the blanks in the following statements. (a) _________ and _________ fibres are obtained from animals. (b) Silk fibres come from _________ of silk _________. (c) Wool yielding animals bear _________ on their body. (d) Hair trap a lot of _________, which is a poor _________ of heat. State whether the following statements are True or False. If false, correct them. (a) Silkworms are caterpillars of silk moth. (b) In India, camels and goats are generally reared for obtaining wool. (c) The rearing of silkworms for obtaining silk is called silviculture. (d) In the process of obtaining wool from fleece, sorting is done after scouring. (e) Yak hair are not used to make woollen fabric. How do the hair of certain animals help in keeping their bodies warm? Short Answer Type Questions Match the items of Column I with the items given in Column II. Various steps involved to obtain wool from fleece are given here. (i) Picking out the burrs (ii) Dyeing in various colours (iii) Shearing (iv) Scouring (v) Sorting Write the above steps in the correct sequence in which they are carried out. Some words related with silk are jumbled up. Write them in their correct form. (a) TURECULRISE (b) WILSMORK (c) BELMURRY (d) RINGLEE Figure 3.1 shows three rings of circles with letters in them. Some of these letters in each ring can form the name of one wool yielding animal. Find the names of these animals. Write a caption for each of the figures given as Figure 3.2 (a–d). Steps for the production of silk are given below in a jumbled order. Arrange them in their proper sequence. (a) Eggs are warmed to a suitable temperature for the larvae to hatch from eggs. (b) Fibers are taken out from the cocoon. (c) After 25 to 30 days, the caterpillars stop eating and start spinning cocoons. (d) The larvae/caterpillars or silkworms are kept in clean trays along with freshly chopped mulberry leaves. (e) Female silk moths lay eggs. (f) Cocoons are kept under the sun or boiled in water. A wholesale woollen fibre dealer gets the woollen fibre of different textures sorted for various purposes. Match the items in Column I with the woollen fibre in Column II. Long Answer Type Questions Paheli went to the market to buy sarees for her mother. She took out a thread from the edge of the two sarees shown by the shopkeeper and burnt them. One thread burnt with a smell of burning hair and the other burnt with the smell of burning paper. Which thread is from a pure cotton saree and which one from a pure silk saree? Give reason for your answer. Explain the phrase – “Unity is Strength” on the basis of the making of fabric from fibre. Write various steps for processing fibres into wool. Describe the life history of silk moth with the help of figures of various stages. « Previous Next » Answers to Multiple Choice Questions 1. (c) 2. (d) 3. (a) 4. (c) 5. (d) 6. (b) 7. (a) 8. (b) 9. (d) 10. (c)