Access to the AP 7th Class Science Study Material 1st Lesson Nutrition in Plants Questions and Answers are aligned with the curriculum standards.
AP 7th Class Science 1st Lesson Nutrition in Plants Questions and Answers
AP Board Solutions Class 7 Science Chapter 1 Nutrition in Plants
Exercise
Question 1.
Why do organisms take food ?
Answer:
- Food is essential for all organisms to survive in the world.
- Food is necessary for all organisms to get growth.
- Food provides energy for movements such as running, walking or raising our arms and legs.
- Food is necessary for replacement and repairing damaged parts of body.
- Food gives us resistance to fight against diseases and protects us from infections.
Question 2.
Distinguish between a parasite and a saprotroph.
Answer:
Parasite | Saprotroph |
1) Parasite feeds on a living organism. | 1) They feed on dead and decaying organism. |
2) They feed on the ready made food from the host. | 2) They take the digested and decayed food. |
3) They feed on the living organisms for their nutrition. | 3) They feed on dead and decaying organisms. |
4) Examples: Cuscuta and Orchids. | 4) Examples: Fungi and some bacteria. |
Question 3.
How would you test the presence of starch in leaves ?
Answer:
- Take a fresh leaf from a plant.
- The leaf is boiled in water for few minutes to kill the cells in the leaf.
- Now, add 1 or 2 drops of iodine solution to this leaf.
- The leaf turns into blue-black colour.
- This blue – black colour indicates the presence of starch in the leaf.
Question 4.
Give a brief description of the process of synthesis of food in green plants.
Answer:
- Green plants are autotrophs.
- They have Chlorophyll in the leaves.
- These leaves use CO2 and water to make food in presence of sunlight.
\(\text { Carbondioxide }+ \text { Water } \frac{\text { Sunlight }}{\text { Chlorophyll }} \underset{\text { (glucose) }}{\text { Carbohydrate }}+\text { Oxygen }\)
Question 5.
Show with the help of a sketch that plants are the ultimate source of food.
Answer:
Question 6.
Fill in the blanks:
a) Green plants are called ………… since they synthesis their own food.
b) The food synthesised by plants is stored as ………… .
c) In photosynthesis solar energy is absorbed by the pigment called ………… .
d) During photosynthesis plants take in ………… and release gas.
Answer:
a) Autotrophs
b) Starch
c) Chlorophyll
d) Carbondioxide, oxygen
Question 7.
Name the following :
i) A parasitic plant with yellow, slender and branched stem.
ii) A plant that is partially autotrophic.
iii) The pores through which leaves exchange gases.
Answer:
i) Cuscuta
ii) Insectivorous plant
iii) Stomata.
Question 8.
Tick the correct answer:
a) Cuscuta is an example of :
i) autotroph
ii) parasite
iii) saprotroph
iv) host
Answer:
a) ii) parasite
b) The plant which traps and feeds on insects is :
i) cuscuta
ii) china rose
iii) pitcher plant
iv) rose
Answer:
b) iii) pitcher plant
Question 9.
Match the items given in Column I with those in Column II:
Column I | Column II |
i) Chlorophyll | a) Rhizobium |
ii) Nitrogen | b) Heterotrophs |
iii) Cuscuta | c) Pitcher plant |
iv) Animals | d) Leaf |
v) Insects | e) Parasite |
Answer:
Column I | Column II |
i) Chlorophyll | d) Leaf |
ii) Nitrogen | a) Rhizobium |
iii) Cuscuta | e) Parasite |
iv) Animals | b) Heterotrophs |
v) Insects | c) Pitcher plant |
Question 10.
Mark ‘T’ if the statement is true and ‘F’ if it is false :
i) Carbon dioxide is released during photosynthesis. (T/F)
Answer: False
ii) Plants which synthesis their food are called saprotrophs. (T/F)
Answer: False
iii) The product of photosynthesis is not a protein. (T/F)
Answer: True
iv) Solar energy is converted into chemical energy during photosynthesis. (T/F)
Answer: True
Question 11.
Choose the correct option from the following :
Which part of the plant takes in carbon dioxide from the air for photosynthesis ?
i) Root hair
ii) Stomata
iii) Leaf veins
iv) Petals
Answer:
ii) Stomata.
Question 12.
Choose the correct option from the following :
Plants take carbon dioxide from the atmosphere mainly through their:
i) roots
ii) stem
ii) flowers
iv) leaves
Answer:
iv) leaves.
Question 13.
Why do farmers grow many fruits and vegetable crops inside large green houses? What are the advantages to the farmers?
Answer:
- It protects crops from diseases and adverse climatic conditions.
- It protects crops from wind and rodents.
- Farmers will get high yield of crops.
- Farmer’s crops are also protected from birds and animals.
Questions given in the lesson
Page No. 2
Question 1.
How plants prepare their own food?
Answer:
Plants prepare their food from simple substances like carbon dioxide and water present in their surroundings by the process of photosynthesis. Water and minerals present in the soil are absorbed by the roots and transported to the leaves.Carbon dioxide from air is taken through the stomata.
The leaves have a green pigment called chlorophyll. It helps leaves to capture the energy of the sunlight. This energy is used to synthesise (prepare) food from carbon dioxide and water. So, leaves of green plants containing chlorophyll synthesise carbohydrates in the presence of sunlight, water and carbon dioxide.
Question 2.
Why our body cannot make food from carbon dioxide, water and minerals like plants do ?
Answer:
Our body cannot prepare food from carbon dioxide, water and minerals like plants due to the absence of chlorophyll pigment.This is the only pigment that can absorb solar rays. Without solar energy, photosynthesis cannot be possible. Solar energy is used to synthesis food from CO2 and H2O.
Question 3.
Whether food is made in all parts of a plant or only in certain parts ?
Answer:
Plants are known to produce food on their own through leaves.
Question 4.
How do plants obtain the raw materials from the surroundings?
Answer:
The synthesis of food in plants occurs in leaves. Therefore, all the raw materials must reach there. Water and minerals obtained from soil, CO}_2$ taken from air through pores on leaves called stomata and solar energy is captured by leaves.
Question 5.
How do they transport them to the food factories of plants ?
Answer:
Water and minerals are transported to the leaves by the vessels which run like pipes throughout the root, the stem, the branches and the leaves.
Page No. 4
Question 6.
How water and minerals absorbed by roots reach the leaves?
Answer:
Water and minerals are transported to the leaves by the vessels which run like pipes throughout the root, stem, branches and the leaves. They form a continuous path or passage for the nutrients to reach the leaf.
Question 7.
What is so special about the leaves that they can synthesise food but other parts of the plant cannot?
Answer:
The leaves have a special green pigment called chlorophyll. Colour of leaves is green because of this chlorophyll.It helps leaves to capture the energy of the sunlight.The chlorophyll pigment has the ability to convert sunlight into the food by, the photosynthesis.
Page No. 6
Question 8.
Boojho has observed some plants with deep red, violet or brown leaves. He wants to know whether these leaves also carry out photosynthesis.
Answer:
Plants with red, violet and brown leaves can also perform photosynthesis as these plants also have chlorophyll, but the green colour of chlorophyll is masked by the presence of the large amount of red, brown and violet pigments in these leaves.
Page No. 8
Question 9.
Why algae are green in colour?
Answer:
Algae contain chlorophyll which gives them the green colour.
Question 10.
Where do the plants obtain nitrogen?
Answer:
Soil has certain bacteria that convert gaseous nitrogen into a usable form and release it into the soil. These soluble forms are absorbed by the plants along with water.
Page No. 10
Question 11.
Whether mosquitoes, bed bugs, lice and leeches that suck our blood are also parasites?
Answer:
Yes, the animals such as mosquitoes, bed bugs, lice and leeches that suck our blood are also parasites because these organisms derive their nutrition from host (human).
Page No. 12
Question 12.
If the pitcher plant is green and carries out photosynthesis, then why does it feed on insects?
Answer:
Pitcher plants grow in a place where the soil has a deficiency of nitrogen compounds so to fulfil the need for nitrogen they feed on insects.
Question 13.
Boojho wants to know how these organisms acquire nutrients. They do not have mouths like animals do. They are not like green plants as they lack chlorophyll and cannot make food by photosynthesis.
Answer:
They have a different mode of nutrition. They secrete digestive juices on the dead and decaying matter and convert it into a solution. Then they absorb the nutrients from it.
Question 14.
Paheli is keen to know whether her beautiful shoes, which she wore on special occasions, were spoiled by fungi during the rainy season. She wants to know how fungi appear suddenly during the rainy season.
Answer:
The fungal spores are generally present in the air. When they land on wet and warm things they germinate and grow. During rainy reason, there are more chances things getting wet. So, fungi spoil more things in rainy reason.
Page No. 14
Question 15.
Boojho says once his grandfather told him that his wheat fields were spoiled by a fungus. He wants to know if fungi cause diseases also.
Answer:
Yes, fungi causes diseases in plants, animals and humans. However, some fungi are also used is medicines.
Question 16.
Paheli told him that many fungi like yeast and mushrooms are useful, but some fungi cause diseases in plants, animals including humans. Some fungi are also used as medicines.
Answer:
Useful fungi : Yeast and mushrooms are useful fungi.Yeast is used in fermentation of dough used for making bread, cake, and used for fermentation of fruit juice to make wine, bear, soy sauce, etc. Mushroom which is a fungi is used as vegetable.
Fungi which causes for diseases : Some fungi spoiled the plants after germinate and growing over them. Some fungi are cause for skin disease in animals. For example, ringworm is a fungal skin disease. Dandruff is also a fungal disease.
Fungi used as medicine : Some fungi are used to make antibiotics, since fungi are natural decomposer Thus, some fungi are used in making weedicides which control unwanted plants in field.
Extended Learning – Activities and Projects
1. Project :
Take a potted plant with broad leaves. Take two strips of black paper and cut out a small square in the centres. Cover a part of two leaves with these papers and secure them with paper clips (Fig.) Keep the plant in sunlight for 2-5 days. Observe the difference in the colour of the covered and the uncovered portions on the leaf. Perform iodine test on this leaf. Did the two parts show different results? Now take second leaf. Remove the strip and expose the covered part to the sunlight for 2-3 days and do the iodine test again. Describe your observations.
Answer:
In this activity, we covered a part of leaf with black paper, compare the colour with the uncovered part and test with iodine solution.
Observations: When we test the covered part of the leaf becomes light green and pale colour.
This covered part does not turn blue-black.
Reason : When we cover a part of a leaf with paper, it can’t photosynthesize and produce starch. Over time, chlorophyll of the covered part translocates to other parts. As a result, the covered part becomes light green and pale. Iodine solution turns blue with starch. Since the covered part does not contain starch, it does not turn blue.
Inference : The sunlight is necessary for photosynthesis.
Question 2.
Visit a green house if there Is one near your place. Observe how they grow plants. Find out how they regulate the amount of light, water and carbon dioxide to grow the plants.
Answer:
- A green house farm is an artificial chamber that keeps plants warmer than the outside.
- For this, the chamber is made of glass, or plastic that allows solar radiation but prevents its escape.
- Desired temperature and humidity are carefully controlled by fans and irrigation.
- This helps the vegetation to grow which is not possible in that area.
- Farmers get advantages of protection of the crops against pests and insects also.
Question 3.
Try growing a sweet potato just in water. Describe your experiment and observations. You can read more on the following.
Answer:
- Place a sweet potato into the jar.
- Fill the jar with water leaving about 1 inch space between the water and the top of the jar.
- Keep the sweet potato in the jar and keep it in full sunlight at home temperature.
- Check the water levels and add more water when needed.
Observations : We can observe and identify the roots, stems and leaves from the sweet potato.
Result : In about 10-15 days, the sweet potato will begin to bud. For the next 3-6 months vines will grow from the sweet potato.
Activities
Activity 1.1 Page No: 6
Question 1.
How do you show that green plants can’t perform photosynthesis in the absence of sunlight?
Answer:
- Take two potted plants of the same kind. .
- Keep one in the dark (or in a black box) for 72 hours and the other in sunlight.
- Perform iodine test with the leaves of both the plants as you did in the class VI.
- Record your results. Now leave the pot which was earlier kept in the dark, in the sunlight for 3-4 days and perform the iodine test again on its leaves.
- Record your observations in your notebook.
Observations: The plant which was kept in dark, does not perform photosynthesis. Hence, during the iodine test, the leaves of this plant didn’t turn into blue – black colour. When we kept that plant in sunlight, for 3-4 days, they turned blue black colour during iodine test.
Inference: Sunlight is necessary for photosynthesis.
Activity 1.2 Page No: 12
Question 2.
Write an activity to observe “bread mould” in your science lab.
Answer:
- Take a piece of bread and moisten it with water.
- Leave it in a moist warm place for 2-3 days or until fluffy patches appear on them.
- Observe the patches under a microscope.
Observations :
- We can observe cotton like threads spread on the piece of bread.
- These organisms are called fungi. They absorb food from the decaying bread. This mode of nutrition in which organisms take in nutrients from dead and decaying matter is called Saprotrophic nutrition.
- The bread mould is Rhizopus.