Here in this post we provided NCERT Exemplar Problem Class 7 Science Nutrition in Plants Chapter 1 Full Explanation by group of Science Experts. We have provided here each questions answer with reason behind the answer.
Hope it help you!
Nutrition in Plants Class 7 Exemplar full Explanation:
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Multiple choice questions:
1) Organisms which prepare food for themselves using simple naturally available raw material are referred to as
A) Heterotrophs
B) Autotrophs
C) Parasites
D) Saprophytes
Answer:- (b) Autotrophs
(Auto- self and trophos- nourishment )
Thus who prepare their own food are Autotrophs.
Plants make their own food. But humans and animals are dependent on plant for food.
2) In the absence of which of the following will photosynthesis not occur in leaves.
A) Guard cell
B) Chlorophyll
C) Vacuole
D) Space between cells
Answer:- (b) chlorophyll
In the absence of chlorophyll pigment photosynthesis cannot occur in leaves. It is a green coloured pigment which every plant have. Chlorophyll capture energy or photo energy form the sunlight which is then used for formation of food with the help of carbon dioxide and water. Therefore in the absence of chlorophyll pigment photosynthesis is almost impossible.
3) Which of the following statement is/ are correct?
I) All Green plats 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
Answer:- (a)I and IV
All green plants can prepare their own food and oxygen is liberated during photosynthesis both sentence are correct among above. Most animals are autotrophs is wrong because most of the animals are heterotrophs. And carbon dioxide is required for photosynthesis.
4) Pitcher plants traps insects because it
A) It is a heterotrophs
B) Grows in soils which lack in nitrogen
C) Does not have chlorophyll
D) Has a digestive system like human being.
Answer:-(b) grows in soil which lack innitrogen.
The trapping of insects by the pitcher plant is because it grows in soil which lack in nitrogen. But for the growth of plant it is very essential nutrient. Lacking of nitrogen in plant is somewhere difficulty in the growth. Thus the pitcher plant developed itself. insects which are trapped by the pitcher plant gives the plant that essential nutrient which is nitrogen.
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) Parasite
Answer:- ( c) Saprophytic
In the yeast, mushroom and bread – mould mode of nutrition is Saprophytic mode of nutrition. Saprophytic nutrition means taking of nutrients from the dead and decaying substances. This is known as Saprophytic nutrients. The organisms which are with have Saprophytic mode of nutrition are known as saprotrophs.
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
Answer:- (a ) stomata
Stomata is present on the leaves in between the guard cells. Stomata which are tiny pores are surrounded with guard cells form which carbon dioxide from the air is taken.
7.) two organisms are good friends and live together. One provides shelter, water, nutrients, while the other prepares and provides food , such an association of organisms is termed as
A) Saprophyte
B) Parasite
C) Autotroph
D) Symbiosis
Answer:- ( d) Symbiosis
Symbiosis is an association or a relationship between two organisms or Animals. This is the relationship between organisms in which both shares shelter, food and nutrition.
8.) Which of the following raw material is available in the air for photosynthesis?
A) Oxygen
B) Carbon dioxide
C) Nitrogen
D) Hydrogen
Answer:- (b) carbon dioxide
Carbon dioxide is needed for the photosynthesis which is available in air, in the presence of sunlight, water and carbon dioxide, photosynthesis occur. But oxygen, nitrogen and hydrogen does not need for photosynthesis process.
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Very Short Answer Question:
9.) Potato and ginger are both underground parts that store food. Where is the food prepared in these plants?
Answer:- potato , sweet potato , ginger these are the plant which are also known as vegetative plants, i.e growth of plant is known as vegetative propagation. These plants store the food inside the soil. What we eat i.e potato or sweat potato these are underground stems which have the stored food mainly starch. But these parts do not make food. The process of formation of food occur above the soil in the leaves or shoot system. Later on Transportation of food occur and the food is stored in underground part.
10.) Photosynthesis requires chlorophyll, and a few other raw material. Add the missing raw materials to the list given below.
Water, minerals, ________, ________.
( A). (B)
Answer:- A) sunlight /light energy
B) Carbon dioxide
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Short Answer Questions:
11.) A goat eats away all the leaves of a small plant (balsam). However , in few days new leaves could see sprouting in the plant again. How did the plant survive without leaves?
Answer:- when a goat eats away all the leaves of a Small balsam plant it does not so much affect the plant. Plant does not only dependent on the leaves for food. Also take many nutrients and water from the soil. The process of making food i.e photosynthesis is carried out mainly in leaves because the presence of chlorophyll pigment. when the food formed, it gets transported to almost every part of the plant andalso stored in the different parts. Thus when the goat eat away all the leaves the plant survived on the stored food.
12.) Unscramble the following to form terms related to modes of nutrients.
A) RASPAEIT
B) ROPEHYTSAP
C) TOROPHAUT
D) SIMIOSYS
Answer:-
A) PARASITE
B) SAPROPHYTE
C) AUTOTROPH
D) SYMBIOSIS
13.) Nitrogen is an essential nutrients for plants growth. But farmers who cultivate pulse crops like green gram, bengal gram, black gram, etc. Do not apply nitrogenous fertilizer during cultivation. Why?
Answer:- the roots of pulses like green gram , bengal gram, black gram etc. have an association or relationship with the soil. These plant’s roots contain an bacterium which is known as Rhizobiumbacteria. These Rhizobiumbacteria develop an relationship with the soil and fixes the nitrogen in soil naturally. Therefore external nitrogenous fertilizer doesn’t need to these type of plants. This type of association is called symbiotic association.These plants like Pulses are mainly cultivated due to these reason also, because it increases nitrogen naturally in soil, which improves the quality of soil.Therefore farmers don’t need to apply nitrogenous fertilizer to pulses plants during cultivation.
14.) Wheat dough if left in the open after few days, starts to emit a foul smell and becomes unfit for use. Give reason.
Answer:-wheat dough when left in open gets fowl smell dye to the growth of fungi on the dough. The fungi which attacks on the though have Saprophytic mode of nutrition. That means it takes the nutrition form the dead and decaying material. When the dough is left in open is attacked by the Saprophytic fungi and thus after some days it gets fowl smell, because the decomposition process starts in the dough due to bacteria and fungi.
15.) Sunlight, chlorophyll, carbon dioxide , water and minerals are raw material essential for photosynthesis. Do you know where they are available? Fill in the blanks with the appropriate raw materials.
a) Available in the plants: ________________
b) Available in the soil : ____________, _________
c) Available in the air. : _____________
d) Available during day: ________________
Answer:-
A) Chlorophyll
B) Water, minerals
C) Carbon dioxide
D) Sunlight
16.) Observe the diagram given as figure. 1.1 and label the following terms given in the box.
Stomatal opening, guard cell.
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Long Answer Questions:
17.) Match the organisms given in column I with their mode of nutrition given in column II.
Column I |
Column II |
a) Mango tree | I)Insectivorous plant |
b) Mushroom | II) Heterotroph |
c) Pitcher plant | III) Autotroph |
d) Cuscuta | IV) saprophyte |
e) Elephant | V) parasite |
Answers:-
A) Mango tree = Autotroph
B) Mushroom = Saprophyte
C) Pitcher plant = Insectivorous plant
D) Cuscuta = parasite
E) Elephant = Heterotroph.
18.) 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?
Answer:- wild animals like tiger, wolf , lion and leopard do not plant as they are carnivorous animals they kill and eat only another small animals. But they are also heterotrophs that means they are dependent on someone else for their food. But plants are Autotrophs they make their own food and thus they are not dependent on anyone else for their food. But the small animals like rabbit, dear, giraffe which is eaten by the wild animals Are dependent on the plants for their food. Thus indirectly wild animals are also dependent on the plants, therefore they cannot survive without plants.
19.) Fill in the blanks of the paragraph given below with the words provided in the box.
Chlorophyll, energy, food, Carbon dioxide, water, photosynthesis
Leaves have a green pigment called _____(a)____ which captures_____(b)_____from sunlight. This ______(c)______ is used in the process of _______(d) _______ and along with other raw materials like _________(e)______ and _______(f)______ synthesize_______(g)_______ .
Answer:-
Leaves have a green pigment called chlorophyll. Which captures energy form sunlight. This energy is used in the process of photosynthesis and along with other raw materials like carbon dioxide and water synthesize food / carbohydratecel
20.) Spot as many organisms as possible in the puzzle given as fig. 1.2 by encirclingthem as shown. Write the names on a sheet of paper and categories them into Autotrophs and heterotrophs. Classify the heterotrophs and herbivores , carnivorous, omnivorous and Saprophytes.
Answer:-
Autotrophs- Rose, mango, bhindi, carrot, Banyan, tulsi, ginger, yam.
Heterotroph– Elephant, ant , yeast, tiger, mushroom, fox, mice, owl, cow,crow, Rabbit , bee, fish.
Herbivorous – elephant, cow, Rabbit, bee.
Carnivorous– fox, tiger.
Omnivores – ant, mice, owl, crow,fish.
Saprophytes- mushroom, yeast.
21.) Can you give me name?
Solve each of the following riddles by writing the name of the organism and it’s mode of nutrition. One riddle is solved to help you.
1.) I am tell but I cannot move. I am green and can prepare my own food.
Answer:- Tree, Autotroph
2.) I live in water; people keep me in an aquarium and feed me._______,_________
Answer:- Fish, Heterotroph
3.) I am small and I can fly . I disturb your sleep, bite you and suck your blood which is my food .__________,_________.
Answer:- mosquito, parasite
4.) I am white and soft . I grow well in the rainy season. Children pluck me from the ground and admire me . I absorb nutrients form decomposed dead parts of plants and animals in the soil._______________,_____________
Answer:- mushroom, Saprophyte.