Life Processes in Plants Class 7 Extra Questions and Answers Science Chapter 10

By tackling these Class 7 Science Extra Questions and Class 7 Curiosity Chapter 10 Extra Question Answer Life Processes in Plants, students will build a solid foundation in the topic.

Class 7 Science Chapter 10 Life Processes in Plants Extra Questions

Class 7 Science Chapter 10 Extra Questions on Life Processes in Plants

Life Processes in Plants Class 7 Very Short Question Answer

Question 1.
Write definition of photosynthesis.
Answer:
The process in which plant prepare their own food in presence of sunlight, chlorophyll, water and carbon dioxide is called photosynthesis.

Question 2.
Which tissue is responsible for transport of food in plants?
Answer:
Transport of food is done by phloem tissue in plants.

Question 3.
Name the tiny pores responsible for gaseous exchange on surface of leaf.
Answer:
Stomata

Question 4.
Why the colour of leaves become blue-black in iodine test?
Answer:
Because of presence of starch the colour of leaves become blue-black in iodine test.

Question 5.
Which gas is released by plant during photosynthesis?
Answer:
Oxygen gas

Question 6.
Which gas is absorbed by plants during respiration?
Answer:
Oxygen gas

Question 7.
Which part of plant is mainly responsible for absorption of water?
Answer:
Roots and root hairs

Question 8.
Which tissue perform the function of transport of water and mineral in plants?
Answer:
Xylem tissue

Question 9.
What is the major product of photosynthesis?
Answer:
Glucose (which is stored as starch later)

Question 10.
State a main difference in photosynthesis and respiration.
Answer:
Carbon dioxide is absorbed in photosynthesis whereas oxygen is absorbed in respiration.

Question 11.
Which part of a plant is called ‘ food factory’’?
Answer:
Leaf

Question 12.
Name an external factor which affects grow th of a plant.
Answer:
Availability of water

Life Processes in Plants Class 7 Short Question Answer

Question 1.
Write name of four factors essential for photosynthesis.
Answer:
Following four factors are responsible for photosynthesis in plants:
(i) Sunlight
(ii) Chlorophyll
(iii) Carbon dioxide
(iv) Water

Question 2.
What is the importance of stomata in plants?
Answer:
Stomata are tiny pores on surface of leaves. These are the main path for exchange of gases (like absorb CO₂ and release O₂ for photosynthesis and absorb O₂ and release CO₂ for respiration) between plants and atmosphere. These are responsible for vaporisation too.

Question 3.
How to find out the presence of starch in leaves by iodine test?
Answer:
When iodine solution is poured on leaves. The leaf become blue-black in colour, which shows the presence of starch. Iodine exhibits blue-black colour which confirms the food synthesis in leaf.

Question 4.
Distinguish between functions of phloem and xylem in plants.
Answer:
Xylem transports water absorbed from roots and minerals to stems, branches and leaves of plants. Phloem transports food (glucose) prepared in leaves to other part of plants like roots, stems, fruits and flowers.

Question 5.
Prove carbon dioxide is essential for photosynthesis.
Answer:
If a plant is placed in a pot having caustic potash (which absorb CO₂) in sunlight, then starch does not form in leaf of that plant. While in plant placed in atmosphere contains CO₂ starch formed hence it is proved that carbon dioxide is essential for photosynthesis.

Question 6.
Why does a plant respire? Write the equation for this process.
Answer:
Plants respire, so they can get energy from food (glucose), which was used for different biological functions like growth, absorption of nutrients etc.

Equation is : Glucose + Oxygen → Carbon dioxide + Water + Energy

Question 7.
Write two differences in photosynthesis and respiration.
Answer:

Photosynthesis	Respiration
1. Only during day time.	During day night both.
2. CO2 is absorbed and O2 is released.	O2 is absorbed and CO2 is released.

Question 8.
Discuss a simple experiment to show water transport in plants.
Answer:
Place a white flowered plant stem in coloured water (mixed with red ink). After some time petals of flower becomes red in colour. It proved that water transported upward with the help of stem.

Question 9.
How does the broad and flat surface of leaf is helpful in photosynthesis?
Answer:
Surface area of leaf increased because of broad and flat structure of leaf. Which helps in

1. Receiving maximum amount of sunlight,
2. It become easy to absorb carbon dioxide from atmosphere which results in aft increased rate of photosynthesis.

Question 10.
What is the significance of the text named “Vrikshayurveda”?
Answer:
It is an ancient Indian text. It records useful observations about plant growth, soil and agricultural practices. It helps to improve crop health, growth and production. Ex. : Preparing organic manure with mixing water, barley, various seeds, like black, green and horse gram.

Life Processes in Plants Class 7 Long Question Answer

Question 1.
Explain photosynthesis process and write its equation.
Answer: Photosynthesis is the process in which green plants prepare their own food by using sunlight w ith the help of simple materials like water and carbon dioxide. This process completed in presence of a green pigment chlorophyll present in leaves. In this process oxygen gas is released as a by-product which purify atmosphere.

hemical equation :
Carbon dioxide + Water → Glucose + Oxygen (In presence of sunlight and chlorophyll)

Question 2.
Write in detail about respiratory process in plants. How it is different from photosynthesis?
Answer:
Respiration is a life-giving process in which plant receives oxygen from atmosphere and decompose food (glucose) and produces energy, water and carbon dioxide. This process continued day and night and plant used the received energy for various biological functions.

Different from photosynthesis : Photosynthesis is a constaictive process in which food is prepared and oxygen is released whereas respiration is destructive process in which energy is released by decomposing food and carbon dioxide is also released.

Question 3.
Explain transport arrangement in different parts of plant.
Answer:
Function of transport is done by special tissues in plants.
Xylem : This tissue transports water absorbed by roots and dissolved mineral salts to upper parts of plant means stems, branches, leaves and flowers. This transport take place from roots to upwards to leaves.

Phloem : This tissue transports food (glucose) prepared by leaves through the process of photosynthesis to all parts of plant like increasing sides, roots, seeds and fruits etc. This transport can be bi-directional.

Question 4.
Prove with an experiment that sunlight is essential for photosynthesis.
Answer:
Cover a leaf of a plant potted in pot from both sides with a black paper so the sunlight could not reach it. Place the plant in sunlight for two- three days. Then plucked that leaf and will do iodine test. We will see that in the part where sunlight did not reached starch would not formed while in opened area of plant starch was formed (blue-black colour of iodine). Hence it is proved that sunlight is essential for photosynthesis.

Question 5.
Describe process of water absorption and transport in plants.
Answer:
Plants absorb water from soil mainly through roots and specifically with root hairs. Root hairs are spreaded between soil particles and absorb water and minerals by osmosis. Absorbed water and mineral are transported by xylem tissue to the upper parts of plant. This water rises up because of evaporation pulling and root pressure and used in photosynthesis after reaching in leaves.

Question 6.
How does different life processes in plants contribute to balance ecosystem?
Answer:
The life processes of plants are very important for ecosystem. Plants receive carbon dioxide from atmosphere and release oxygen, this purify air and organisms get ‘ oxygen to breath. They use oxygen in respiration and release carbon dioxide which maintains the cycle of gases.

These processes are base of growth in plants, these plants provide food to all organisms as a producer of food chain. Thus, these processes play an important role in maintaining balance of environment.

Question 7.
“Plants are protector of our environment.” Justify the statement on the basis of process of photosynthesis.
Answer:
The process of photosynthesis done by plants make them our true protector. First of all, this process maintains balance of carbon dioxide and oxygen in atmosphere. Plants receive the harmful gas carbon dioxide released by humans and other oiganisms and plants release the life-giving oxygen gas. So, they function to purify air. Secondly, they are base of food chain. The food prepared by plants is directly or indirectly source of energy for the whole animal-kingdom. Third, these are helpful in controlling temperature. So, no doubt through photosynthesis, plants play role of our protector.

Question 8.
Describe in detail transport system of material in plants. Compare functions of xylem and phloem tissues.
Answer:
Transport of materials in plant take place by a complex and well-organised system, which have two specific vascular tissues-xylem and phloem and they play main role.

Xylem : This tissue transport water absorbed by roots and dissolved mineral salt to the upper parts of plants like stem, leaves and flowers. Its cells are dead, hollow and long which builds a tube, through which water rises up quickly. This transport is always unidirectional from root to leaf.

Phloem : This tissue transports the food prepared by plants through the process of photosynthesis to all parts of plant like growing up tissues, storage organs (roots, fruits) etc. Its cells are live. Transport can take place in both directions like upward to downward and downward to upward. So these both tissues combinedly execute the function of balanced distribution of substances of plant body.

Question 9.
Explain respiration in plants in details. Does all parts of plant respire ? Clarify.
Answer:
Respiration is a universal and essential life process by which plants get energy through decomposition of food (glucose) in cell of their body. This process occurs continuously in plants as well. In this process plants receive oxygen which reacts with glucose after reaching in cells. As a result of this reaction water, carbon dioxide and enough energy is released. This energy is used by plants in different functions of life like growth, absorption of water and minerals and transport etc.

Question 10.
Explain any four factors affecting photosynthesis by describing that how these factors affect this process.
Answer:
Rate of photosynthesis depends on different factors:
Intensity of sunlight : Rate of photosynthesis increased with increasing intensity of light to an extent because more energy is available. But this rate can be constant or decrease due to intense light.

Concentration of carbon dioxide :
Photosynthesis rate is increased when amount of CO₂ is increased in atmosphere because it is raw material. Amount of CO₂ is increased in green houses for growth of plant.

Temperature : Photosynthesis is an enzyme- regulated process. Its rate is maximum on an optimal temperature (25-30°C). Reaction of enzyme is slower on very high or low temperature, and rate is decreased.

Availability of water : Water is an essential raw material for photosynthesis. Water deficiency can cause closing of stomata, which stopped entry of CO₂ and rate of photosynthesis decreased quickly.

Question 11.
Highlight the importance of life processes accomplished by plants in human life.
Answer:
The life processes of plants are very important in human life. First of all plant not only prepare food for whole animal kingdom by photosynthesis, even they release oxygen essential for us to respire and absorb harmful carbon dioxide and purify environment.

Secondly, plants grown by own through respiration which provides us wood, fibres, medicines and many products. Third, because of transport the nutrients reached to all parts of plant and produce fruits, vegetables and grains which are the main part of human diet. Life cannot be imagined without these life-processes.