Transpiration Srijan Publications Solutions for ICSE Class-10 Biology Ch-5

Transpiration Srijan Publications Solutions for ICSE Class-10 Biology Ch-5. We Provide Solutions of Very Short Answer Type, Short Answer Type, Long Answer Type Questions and MCQs of Exercise-5 Transpiration Srijan Publications ICSE Class-10 Ch-5. Visit official Website CISCE for detail information about ICSE Board Class-10.

Transpiration Srijan Publications Solutions ICSE Class-10 Ch-5

Board	ICSE
Publications	Srijan Publications
Subject	Biology
Class	10th
Writer	Veer Bala Rastogi
Chapter-5	Transpiration
Topics	Solutions of MCQs, Very short and Short Long Answers Questions
Edition	for 2022-2023 Academic Session

A. VERY SHORT ANSWER TYPE QUESTIONS

Ch-5 Transpiration Srijan Publications ICSE Class-10 Biology Solutions

(Page-69)

Questions 1: Give one word for the following:

(a) Evaporation of water from the aerial parts of the plant.

Ans:- Transpiration

(b) Structures through which most of the transpiration takes place.

Ans: Stomata

Ans: bleeding

(d) An apparatus to compare the rate of transpiration in cut shoot

Ans: Ganong’s potometer

(e) Respiratory openings found on the stem of woody plants

Ans: lenticels

(f) Loss of water in the form of droplets from the margin of leaves.

Ans: guttation

(g) Exudation of sap from injured parts of a plant.

Ans: guttation

(h) A plant with sunken stomata.

Ans: Nerium, Pine, Acacia all are xerophyte

(i) The tissue responsible for the movement of water from stem to leaves.

Ans: Xylem

Questions 2. Define the following terms:

(a) Transpiration: Loss of water in the form of vapor from the aerial part of plant

(b) Potometer: an apparatus for measuring the rate of transpiration in a plant by determining the amount of water absorbed.

(d) Hydathodes: Hydathodes are the pores present at the leaf margin where vascular supply ends (vein). The loss of water in the form of liquid take place in these pores.

(e) Guttation: Effects of root pressure is also observable at night and early morning when evaporation is low, and excess water collects in the form of droplets around special openings of veins near the tip of grass blades, and leaves of many herbaceous parts. Such water loss in its liquid phase is known as guttation

(f) Bleeding: The exudation of liquid from the cut or injured surface of plants, such as date palm and Palmyra palm is known as bleeding.

Questions 3. Write one main function of the following :

(a) Stomata: control the exchange of gases—most importantly water vapour and CO₂—between the interior of the leaf and the atmosphere

b) Sunken stomata: Sunken means hidden stomata or stomata those which are not directly exposed to surface. It is in a small pit, which protects the escaping water vapour from air currents, decreasing water loss from the leaf.

(c) Lenticels: It functions as a pore and participates in the direct exchange of gasses between the internal tissues and atmosphere through the bark, which is otherwise impermeable to gasses

(d) Hydathode: Hydathodes are the structures that discharge water from the interior of the leaf to its surface in a process called guttation

Questions 4. State whether the following statements are true or false. If false, rewrite the correct form of statements.

(a) Gaseous exchange in plants occurs in body cells.

False , Gaseous exchange in plants occurs in aerial part of body cells.

(b) Dry cobalt chloride paper tums blue when moist

False, Dry cobalt chloride paper tums Pink when moist

False, The wall of guard cells towards stomata is thick

(d) The opening and closing of stomata is regulated by the turgidity of guard cells. True

(e) Transpiration is more from the upper surface as compared to lower surface in a dorsiventral leaf

False, Transpiration is lesser from the upper surface as compared to lower surface in a dorsiventral leaf

(f) Transpiration takes place only during night.

False. Transpiration takes place during day

Note:– The rate of transpiration is lower at night than the transpiration, which occurs during the day time in the presence of sunlight

(g) Plants have thick cuticle to reduce transpiration. True

(h) Maximum transpiration in tall trees occurs through lenticels. True

(i) Transpiration creates an upward pull for the movement of sap. True

(j)Transpiration will be fastest when the day is cool, humid and windy.

False: Transpiration will be slower when the day is cool, humid and windy

Questions 5. Given below are certain biological statements which are incomplete and hence incorrect. Rewrite the correct form of the statement by inserting suitable word /words at the right place. Do not delete any word already given in the statement. Underline the inserted word / words.

(a) Transpiration is the loss of water from the leaves of a plant.

correct form: Transpiration is Loss of water from the aerial part of plant

(b) Ganong’s potometer is used to show transpiration in plants.

correct form: Ganong’s potometer is used to measure transpiration in plants.

correct form: More transpiration occurs from the Lower Surface of dorsiventral leaf.

(d) Opening and closing of stomata is controlled by guard cells.

correct form: Opening and closing of stomata is controlled by Turgor of guard cells.

(e) Guttation is the loss of water along the margins of leaves.

correct form: Guttation is the loss of water along the margins or tip of leaves.

(f) Bleeding is the exudation of water or sap from the parts of a plant.

correct form: Bleeding is the exudation of water or sap from the injured parts of a plant

Questions 6. Note the relationship between the first two words and suggest the word/words for the fourth place.

(a) Stomata : Transpiration :: Hydathodes :

(b) Dry cobalt chloride paper: Blue : Moist cobalt chloride paper

Answer :

(a) Guttation

(b) Pink

Questions 7. Given below is a set of five terms. Rewrite the terms in logical sequence as directed at the end of statement.

Stoma, Mesophyll cells, Xylem, Substomatal space, inter cellular space. (loss of water due to transpiration).

Answer : Mesophyll cells-intercellular spaces–xylem-substomatal space-stoma

B. Short Answer Type Question

Ch-5 Transpiration Srijan Publications ICSE Class-10 Biology Solutions

(Page-69)

Questions 1. Answer the following questions:

(a) How does water vapor escape stomata?

Ans: As the sun warms the water inside the plants leaves, transpiration occurs. This warming causes most of the water to turn into vapor and evaporate. The water vapor escapes into the air through the stomata. The water vapor absorbs heat as it escapes, which cools the inside of the leave

(b) How do stomata regulate the transpiration?

Ans: Stomata consist of microscopic pores, each flanked by a pair of . Guard cells can increase or decrease the size of the pore via changes in their turgor status, hence regulating both CO₂ entry into the leaf and transpiration, or the loss of water from the leaf.

(c) What is Ganong’s potometer used for? Write any two limitations of this apparatus.

Ans: The Ganong’s potometer is used to measure the transpiration rate in a laboratory

limitations of Ganong’s potometer

The twig placed on the glass cylinder might not stay alive for a longer time.
The introduction of an air bubble in the horizontal bar is very difficult and time-consuming.
A slight change in the atmospheric temperature might affect the position of the air bubble

(d) Name the three kinds of transpiration. Out of these, which has the maximum rate and which has the minimum rate of transpiration?

Ans:

Stomatal transpiration.– More transpiration 90%
Lenticular transpiration. More than cuticular but less than stomatal
Cuticular transpiration- least transpiration

(e) What is lenticular transpiration? Give one major difference between lenticular transpiration and cuticular transpiration.

Ans: This type of transpiration is the loss of water from plants as vapor through the lenticels. The lenticels are tiny openings that protrude from the barks in woody stems and twigs as well as in other plant organs

one major difference between lenticular transpiration and cuticular transpiration.

Lenticular	Stomatal
Lenticels are special opening that develops on the barks of the older stem in place of stomata.	The amount of transpiration from lenticels certainly more than the cuticular transpiration, but very much less than the stomatal transpiration.

(f) Name any three factors that affect the transpiration. How do they reduce the rate of transpiration?

Ans: factors that affect the transpiration

Sunlight: During daytime, the rate of transpiration is faster. …
Temperature: Transpiration is faster on hot summer days as compared to cold winter.
Wind: Transpiration is more when the wind is blowing faster as water evaporates faster from the leaves.
Humidity: Transpiration is reduced if the air is humid.

(g) Mention three adaptations found in plants to reduce transpiration.

Ans :- three adaptations found in plants to reduce transpiration.

Adaptation	Explanation
Leaves reduced to spines	Reduces the surface area for transpiration
Reduced number of stomata	Reduces the transpiration rate
Waxy leaf cuticle	Impermeable to water, which stops evaporation

(h) Droplets of water may sometimes be seen along the margins of the leaves of a tomato plant growing in wet soil, in the morning. Are these dew drops? Comment on your answer.

Ans: The leaves of certain plants exhibit droplets of water along their margins in the morning. This particularly happens in plants growing in warm humid conditions. A humid environment hampers transpiration while the roots continue to absorb water from the soil. This builds up a big hydrostatic pressure within the plant and “forces out” the excess water directly from the tips of veins in the leaf. Special pore-bearing structures called hydathodes are present on the margins of the leaf to allow this exudation.

(i) What is wilting? Some plants show wilting of their leaves during mid-day even when the soil is well watered. Why is it so?

Ans: Wilting refers to the loss of cellular turgidity in plants which results in the drooping of leaves or plant as a whole because of lack of water. During noon the rate of transpiration exceeds the rate of absorption of water by roots. Due to the excessive transpiration the cells of leaves lose their turgidity and wilt.

(j) List any three major factors that affect the transpiration. How do they accelerate the rate of transpiration?

Ans:

Intensity of sunlight.
Temperature.
Velocity of wind.

Questions 2. Give differences between the following:

(a) Transpiration and evaporation

Transpiration	Evaporation
It is a biological process.	It is a physical process.
Transpiration is a slow process.	Comparatively a fast process.
Occurs in living tissues.	Involves non-living matter.
In the process of transpiration water is lost from plant cells	In this process, water is lost from the surface of plant parts

(b) Transpiration and guttation

	Transpiration
1.	Loss of water in vapour form.	1.	Loss of water in liquid form.
2.	Water doesn’t contain any dissolved solutes.	2.	Water contain many dissolved solutes.
3.	It occurs during daytime.	3.	It occurs during the night or early morning hours.
4.	It is a rapid process.	4.	It is a slow process.
5.	It occurs through stomata.	5.	It occurs through hydathodes.
6.	Increased transpiration causes wilting.	6.	Increased guttation is related to low transpiration and high root pressure, not wilting

(c) Stomata and hydathodes

Sl. No.	Stomata	Hydathode
1	Stomata are associated with Transpiration.	Hydathodes are associated with Guttation.
2	Stomata also facilitate exchange of gases like oxygen and carbon dioxide.	Hydathodes do not have any role in the gaseous exchange in plants.
3	Stomata are present on the epidermis of leaf, young stem and floral parts.	Hydathodes are present on the margins of leaf where the vascular supply (vein) ends.
4	Stomata remain closed at night and opened in the day time.	Hydathodes always remain open (both day and night).
5	The opening and closing of stomata can be regulated by guard cells.	There is no opening and closing mechanism for hydathodes, hence the hydathodes always remain open.

(d) Stomatal and lenticular transpiration


1.	Loss of water in the form of water vapour through minute pore called stomata.	Loss of water in the form of water vapour through lenticels.
2.	Stomata are confined to epidermis of green shoot and leaves.	Lenticels are confined in woody stem and fruits..
3.	It amounts for 90% to 95% of the water transpired from leaves.	It amounts for 1% to 5% of the total water oss by the plants.

(e) Guttation and bleeding

Guttation	Bleeding
It is the removal of excess water from the plants because of excess water buildup in the plant.	It is the removal of water from the plant because of injury.
Water escapes from specialised structures called hydathodes.	Water escapes in the form of sap from the injured part of the plant.
It occurs from edges of leaves.	It occurs from cuts found in plants.
It happens due to the pressure presents in the xylem.	It happens due to pressure in sieve tubes.

Questions 3. Give reasons for the following:

(a) Transpiration cools the plant.

Ans: rapid loss of water in the form of water vapour from the aerial parts of the plant through transpiration brings down their temperature. Transpiration thus provides a significant cooling effect which keeps the plant from being over heated.

(b) More transpiration occurs from the lower surface of a dorsiventral leaf.

Ans : More transpiration occurs from the lower surface of a dorsiventral leaf. There are more stomatal openings on the lower surface of a dorsiventral leaf and therefore, more transpiration occurs from the lower surface.

(c) Water droplets are seen on the inside of a polythene bag containing leafy vegetables.

Ans : The potted plant covered with polythene bag is kept in the sunlight there will be the loss of water through the stomata present on the leaves. The water drops will appear inside the polythene bag as a result of a loss of water from the stomata. This is due to transpiration.

(d) In hot summer months, most herbaceous plants wilt at noon and recover in the evening.

Ans : During hot summer days, most plants wilt during the noon and recover in the evening. Wilting of leaves in this situation is because of the increase in the rate of transpiration

(e) Water transpired is the amount of water absorbed.

Ans: Plants absorb water continuously through their roots, which is then conducted upwards to all the aerial parts of the plant, including the leaves. Only a small quantity of this water i.e. about 0.02% is used for the photosynthesis and other activities. The rest of the water is transpired as water vapour. Hence water transpired is the water absorbed.

(f) Leaves are reduced to spines in cactus.

Ans: In case of cactus or xerophytic plants, leaves are redued to spines to prevent loss of water through transpiration and stem performs the process of photosynthesis.

(g) Presence of sunken stomata in Nerium.

Ans : In case of cactus or xerophytic plants, leaves are redued to spines to prevent loss of water through transpiration and stem performs the process of photosynthesis

(h) A higher rate of transpiration is recorded on a windy day rather than on a calm day.

Ans : Transpiration increases with the velocity of wind. If the wind blows faster, the water vapour released during transpiration is removed faster and the area outside the leaf does not get saturated with water vapour. So, higher rate of transpiration is recorded on a windy day rather than a calm day.

(i) Anti- transpirants can be used to keep cut flowers fresh for a long time.

Ans : Antitranspirants are used to reduce the process of transpiration. These are generally applied to cut flowers and transplanted shrubs etc thus preventing them from early drying out by bloacking the hydrogen ion transport from the stomatal cells

(j) The leaves of certain plants roll up on a bright sunny day.

Ans: The leaves of certain plants roll up on a bright sunny day to reduce the exposed surface and thus reduce the rate of transpiration

C. Long Answer Type Questions

Ch-5 Transpiration Srijan Publications ICSE Class-10 Biology Solutions

(Page-70)

Questions 1. Explain how the rate of transpiration is affected on:

(a) a windy day, (b) a foggy day.

Answer :

(a) a windy day: On a windy day, the rate of transpiration increases because the water vapour released during transpiration is quickly removed with the moving air. This does not allow the water vapour to saturate in the surrounding region of the plant and hence more transpiration.

(b) a foggy day: A foggy day has more moisture in the air. Due to more moisture, the air cannot absorb much water vapour released by the plants. Therefore, the rate of transpiration decreases.

Questions 2. List any four advantages of transpiration to the plant.

Answer : Advantages of transpiration:

It helps in the exchange of gases.
It helps in sending out excessively absorbed water by plants. …
It helps in the absorption and distribution of water in plants. …
It provides coolness to the plant body.
Osmotic balance of the cell is maintained by the process of transpiration

Questions 3. Suppose you have a small rose plant growing in a pot. How would you demonstrate transpiration in it?

Answer :

REQUIREMENTS:

Bell jar
Well watered potted plant
Rubber sheet
Glass plate

PROCEDURE:

Take the well watered potted plant and cover it with the rubber sheet. The aerial parts of the plant should be left uncovered.
Put the plant on the glass plate and cover with the bell jar.
Prepare a same setup but without a plant in the second bell jar.
Place the apparatus in sunlight for sometime.

OBSERVATIONS:

Water drops appear inside the walls of the bell jar containing potted plant whereas no water drops appear in the bell jar without a plant. This demonstrates that water is evaporated from the surface of leaves in presence of sunlight.

Questions 4. Briefly explain how the rate of transpiration is affected by:
(a) intensity of light
(b) humidity of atmosphere

Answer :

(a) During the day, the stomata are open to facilitate the inward diffusion of carbon dioxide for photosynthesis. At night they are closed. Hence more transpiration occurs during the day. During cloudy days, the stomata are partially closed and the transpiration is reduced

(b) If the air outside is humid the rate of transpiration is reduced since the outward diffusion of internal water vapour is affected.

— : End of Transpiration Srijan Publications Solutions for ICSE Class-10 Biology Ch-5 :–

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