Absorption by Roots Srijan Publications Solutions ICSE Class-10 Ch-4

Absorption by Roots Srijan Publications Solutions ICSE Class-10 Ch-4. We Provide Solutions of Very Short Answer Type, Short Answer Type, Long Answer Type Questions and MCQs of Exercise-4 Absorption by Roots and Rise of Water up to xylem Srijan Publications ICSE Class-10 Ch-4. Visit official Website CISCE  for detail information about ICSE Board Class-10.

Absorption by Roots and Rise of Water up to Xylem Srijan Publications Solutions for ICSE Class-10 Biology Ch-4

Board	ICSE
Publications	Srijan Publications
Subject	Biology
Class	10th
Writer	Veer Bala Rastogi
Chapter-4	Absorption by Roots and Rise of Water up to xylem
Topics	Solutions of  MCQs, Very short and Short Long  Answers Questions
Edition	for 2022-2023 Academic Session

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A. VERY SHORT ANSWER TYPE QUESTIONS

Absorption by Roots and Rise of Water up to Xylem Srijan Publications Solutions for ICSE Class-10 Biology Ch-4

(Page-54)

Questions 1: Answer the following questions:

(a) Give the specific function of the xylem found in the plants.

(b) What is cell sap?

Answer :

(a) transports water and nutrients from the plant–soil interface to stems and leaves, and provides mechanical support and storage

(b) Liquid content in the vacuoles of plant cell is called cell sap. The cell sap contains sugars, amino acid, proteins, minerals and metabolic wastes

Questions 2: Give one word for the following:

(a) The process by which molecules distribute themselves evenly within the space they occupy.

(b) Process by which water enters root hair.

(c) Term for the inward movement of solvent molecules through the plasma membrane

(d) The process by which raisins swell up when placed in a beaker filled with water.

(e) Movement of molecules from a region of higher concentration to a region of lower concentration.

(f) Pressure by which water enters the root hair.

(g) The tissue concerned with upward conduction of water in plants.

Answer :

(a) Diffusion

(b) Endosmosis.

(c) osmosis

(d) Endosmosis

(e) diffusion

(f) Osmotic pressure

(g) xylem

Questions 3:  Fill in the blanks with suitable words.

(a) Osmosis is the movement of water molecules from its region of high concentration to its region of low concentration through a ….semi permeable membrane…. membrane.

(b) Hypotonic solution is one in which ions outside the cell are …Less Concentration

(c) In a hypotonic solution, the solution outside the cell has lower solute concentration than …….inside…… the cell.

(d) Bending movements of certain flowers towards the sun are the example of ..nastic movements…..

(e) In active transport, the ions outside the roots are…transported inside against their concentration gradient.

(f) In …active transport,….. ions of a substance move from their lower concentration to higher concentration using the energy of the cell.

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

(a) Root hair are thin, delicate elongations of cortex.

(b) Opening and closing of stomata is regulated by osmosis

(c) The shrinkage of protoplasm occurs when a cell is kept in hypotonic solution.

(d) Cells that have lost their water content are said to be deplasmolysed.

(e) Addition of salt to pickles prevents the growth of bacteria as they turn turgid.

(f) Xylem is the water conducting tissue in plants.

(g) Transpiration pull is essential to conduct water in herbs.

Answer :

(a) True

(b) True

(c) False , The shrinkage of protoplasm occurs when a cell is kept in hypertonic solution

(d) True

(e)

(a) False,  Addition of salt to pickles prevents growth of bacteria because they turn flaccid.

(f) True

(g) True

Questions 5. Define the following terms:

(a) Diffusion

(b) Osmosis

(c) Turgor pressure

(d) Plasmolysis

(e) Root pressure

(f) Turgidity

Answer :

(a) “Diffusion is the movement of molecules from a region of higher concentration to a region of lower concentration down the concentration gradient.

(b) osmosis is the movement of water molecules from a solution with a high concentration of water molecules to a solution with a lower concentration of water molecules, through a cell’s partially permeable membrane.

(c) Turgor pressure is the hydrostatic pressure in excess of ambient atmospheric pressure which can build up in living, walled cells. Turgor is generated through osmotically driven inflow of water into cells across a selectively permeable membrane; this membrane is typically the plasma membrane

(d) the process of contraction or shrinkage of the protoplasm of a plant cell and is caused due to the loss of water in the cel

(e) Force that helps to drive fluids upward into the water-conducting vessels (xylem). It is primarily generated by osmotic pressure in the cells of the roots

(f) Turgidity refers to the state of being turgid or swollen due to high fluid content inside the cell

Questions 6. Given below is a set of some terms. Rewrite the terms in logical sequence as directed at the end of the statement.

Cortical cells, Root hair, Soil, water, Endodermis, Xylem. (entry of water into the plant from an object)

Answer : Soil water, Root hair, cortical cells, endodermis, xylem

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B. Short Answer Type Questions.

Absorption by Roots and Rise of Water up to Xylem Srijan Publications Solutions for ICSE Class-10 Biology Ch-4

(Page-55)

Questions 1. Answer the following questions.

(a) How are roots adapted for absorption of water? Give three ways?

(b) Seeds when kept in water swell up and burst their seed coats Why?

(c) What is the significance of osmosis?

(d) What are isotonic, hypotonic and hypertonic solutions?

(e) What is the difference between a turgid and a flaccid cell? Explain briefly.

(f) How does turgor pressure help in closing and opening of stomata?

(g) What is the utility of plasmolysis?

Answer :

(a) Root hair cells are adapted for taking up water and mineral ions by having a large surface area to increase the rate of absorption. They also contain lots of mitochondria , which release energy from glucose during respiration in order to provide the energy needed for active transport.

(b) The seeds swell up when soaked in water due to imbibition and endosmosis. The force generated by the water thus absorbed is strong enough to make the seed coats burst. Hence, soaked seeds when kept in a fully filled closed container burst it open with pressure

(c) Osmosis induces cell turgor which regulates the movement of plants and plant parts.

(d) Hypotonic has a lower concentration of fluid, sugars and salt than blood. Hypertonic has a higher concentration of fluid, sugars and salt than blood. Isotonic has similar concentration of fluid, sugars and salt to blood

(e) The main difference between a turgid cell and flaccid cell is that a turgid cell contains more water and a flaccid cell lacks water. In plants when the stomatal cells become turgid the guard cell opens and when they become flaccid the guard cell closes.

(f) The turgor pressure, which is caused by the osmotic flow of water in the guard cells, controls the opening and closing of stomata. When the guard cells become turgid, they expand, causing stomata to open. Guard cells become flaccid as they lose water, causing stomatal closure.

(g) Plasmolysis helps in the preservation of meat and fish by salting. It is also helpful in the preservation of jellies and jams by adding concentrated sugar solution to them. It helps in plasmolysing the spores of bacteria and fungi.

Questions 2. Give differences between the following:

(a) Diffusion and osmosis

Ans:- Diffusion can occur in any medium, whether it is liquid, solid, or gas. Osmosis occurs only in a liquid medium. Diffusion does not require a semipermeable membrane. Osmosis requires a semipermeable membrane

(b) Tonoplast and plasma membrane

Ans:-

Tonoplast	Plasma membrane
Tonoplast is the membrane around the vacuole which is present in the cell.	Plasma membrane is the membrane around the cytoplasm and thus covers the entire cell

 

(c) Turgidity and flaccidity

Ans: The main difference between turgidity and flaccidity is that turgidity is caused by the movement of water into the cell by endosmosis when it is placed in a hypotonic solution whereas flaccidity is caused by the movement of water out of the cell by both endosmosis and exosmosis when it is placed in an isotonic solution

(d) Turgor pressure and wall pressure

Ans:- Wall pressure is the pressure applied by the cell wall on the cell’s contents. Turgor pressure is the pressure which is exerted by the cytoplasm on the cell wall.

(e) Plasmolysis and deplasmolysis

Ans: Plasmolysis usually refers to loss of protoplasm or water from the cell and deplasmolysis refers to the entrance of water into the cell. Plasmolysis is the breakdown of the plasma under the hypertonic solution and the deplasmolysis occurs due to deposition of plasma in the cell wall.

Questions 3. Give reasons for the following:

(a) Raisins swell up when kept in water

Reason: A phenomenon called endosmosis takes place when raisins are placed in water for few hours. When raisins are soaked in water, they swell. All this is due to the process of osmosis. The water molecules pass the cell membrane of the raisins and the raisins thus get swollen

(b) Grapes shrink when kept in honey.

Reason: Grapes were put in sugar solution i.e., in hypertonic solution. Due to which exosmosis occurs in which outward movement of the water molecules from the lower solute concentration to higher solute concentration takes place through grapes covering. It results in shrinking of grapes

(c) Root hair become flaccid when too much chemical fertilizers are added to the moist soil around it.

Reason: Addition of too much fertilizer to the moist soil results in flaccidity of root hair, because the concentration of soil solution increases and water starts coming out of the root hairs due to the process of osmosis

(d) Freshwater fish cannot survive in sea water.

Reason: The sea water is saline having more concentration of salts and acts as hypertonic solution for the fresh water. So fresh water fish cannot survive in sea water as it causes the plasmolysis of the cells of the fish and ultimately the fish will die

(e) The body of marine fish often bursts when placed under tap water.

Reason: The cells of marine fish burst when introduced to tap water. The introduction of the marine fish to freshwater would result in the rushing of water into the cells because of the process of endocytosis and cause the cells of the marine fish to swell and burst

(f) Grass is killed if salt is sprinkled on it.

Reason: This causes gaps to form between the membrane and the cell wall and so, the plant cell completely shrinks. – This is why when salt is sprinkled on the growing grass, it becomes a hypertonic solution phenomena and thus grass is killed at that spot.

(g) The leaves of Mimosa pudica plant droop down when touched.

Reason: Seismonasty is a nastic movement. When any organ of Mimosa pudica is touched, the stimulus reaches the base of the leaf. Owing to this stimulus, the turgor of lower half of pulvinus is lost and the leaf droops down.

(h) Herbaceous plants growing in a well-watered soil are found to wilt on a hot day.

Reason: On a hot day, herbaceous plants wilt even in well watered soil because their rate of transpiration exceeds the rate of water absorption by the roots. Due to less water in the cells, they become flaccid and leaves become soft and wilt

(i) Wilted leaves become crisp/firm when placed in cold water for a while.

Reason:  Wilted lettuce leaves when kept in cold water absorb water through endosmosis. The cells become turgid and leaves be come crisp

Questions 4. Given here is an example of a particular structure and its functional activity, eg, leaves and photosynthesis. On similar patten, complete the following.

(a) Root hair and …..absorb water ….……

(b) Xylem and ……conduct water…….….

(c) Phloem and …...transport food.……….

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C. Long Answer Type Question

Absorption by Roots and Rise of Water up to xylem Srijan Publications Solutions ICSE Class-10 Biology Ch-4

(Page-55)

Questions 1. What is root pressure? How can you demonstrate it experimentally?

Answer : root pressure, in plants, force that helps to drive fluids upward into the water-conducting vessels (xylem). It is primarily generated by osmotic pressure in the cells of the roots and can be demonstrated by exudation of fluid when the stem is cut off just above ground

Questions 2. Two potato cubes, cach1 cm in size, were placed separately in two containers A and B, The container A has water and the container B has concentrated sugar solution. After 24 hours, when the cubes were examined, the one which was placed in water was found to be firm and had increased slightly in size and the other which was placed in concentrated sugar solution was found to be soft and had decreased in size. Use the above information to answer the questions that follows :

(a) Account for the firmness and increase in size of the potato cube which was placed in water.

(b) Account for the softness and decrease in size of the potato cube which was placed in sugar solution.

(c) Name and define the physical process being investigated in the experiment.

Answer :

(a) Endo-Osmosis

(b) Exo-Osmosis

(c) Osmosis

Questions 3. The following paragraph is related to absorption of water from the soil. Copy and complete the following paragraph by selecting the correct word from those given in the box. You may use the term only once.

Exosmosis, Hypertonic, Osmosis, Isotonic, Hypotonic, Cortical, Endosmosis

Water enters the root hair from the soil by the process of …………. . This is because the solution in the soil is ……………..,  whereas the cell sap in the root hair cell is ……………….. . The water then passes through the ………….  cells by cell to cell ……………  and reaches the xylem of the root.

Answer : 

Water enters the root hair from the soil by the process of endosmosis. This is because the solution in the soil is hypotonic whereas the cell sap in the root hair cell is hypertonic. The water then passes through the cortical cells by cell to cell osmosis and reaches the xylem of the root.

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