Selina solutions concise biology class 8 icse Solutions for Chapter 1 transportation in plants

Q1) Draw a magnified view of the root-hair, and describe, how it helps in the absorption of water from the soil.

Q2) How does transpiration help the roots absorb water and minerals from the soil?

Practice Question:

“Raisins swell in water, and grapes shrink in syrup.” Explain this phenomenon briefly.

Q3) Define the three processes by which plants absorb water and minerals from the soil.

Q4) How water absorbed by the roots is important for the plants?

Q5) Name the factors which affect the rate of transpiration? State their role in each case.

Q6) Mention the two ways in which transpiration helps the plants.

Q7) Describe an experiment to show that the plant loses water through its leaves.

Q8) Name any three minerals whose deficiency causes diseases in plants. Give the symptoms of each deficiency.

Q9) List out the differences between xylem and phloem.

Q1) Put a tick mark against the correct alternative in the following statements:

(a) Diffusion occurs when molecules move:

1. From lower concentration to higher concentration.

2. From higher concentration to lower concentration through a membrane.

3. From higher concentration to lower concentration.

4. When energy is used.

(b) The ascent of sap in plants takes place through:

1. Cortex

2. Epidermis

3. Xylem

4. Phloem

(c) if the xylem vessels of a plant are plugged :

1. The leaves will turn yellow

2. No food will be made

3. The plant will wilt (shrivel)

4. The plant will continue to grow

(d) The force responsible for the ascent of sap is:

1. Capillary force

2. Root pressure

3. Transpirational pull

4. All three

(e) raisins swell when put in:

1. Rain water

2. Tap water

3. Mustard oil

4. Saturated sugar solution

(f) the root-hairs are suited for absorbing water from the soil because:

1. They have a large surface area

2. They have a semi-permeable membrane

3. They contain a solution of higher concentration than the surrounding water

4. All three

(g) Transpiration is defined as:

1. The rise of water up to the stem of the plant.

2. The elimination of water with dissolved water products.

3. The loss of water as water vapour from the aerial parts of a plant.

4. The loss of water as water vapour from the roots as well as the leaves of the plant.

(h) which one of the following favours the fastest transpiration rate?

1. A cool, humid, windy day,

2. A hot, humid, windy day,

3. A hot, humid, still day,

4. A hot, dry, windy day,

Q1) An experiment was set up as shown in the figure below. After some time, the Water level in test tube A fell down but not in test tube.

Why was there a fall in the water level of test tube A and not in that of test-tube B?

Q2) How are roots useful to the plants? Give any two points.

Q3) What do xylem vessels carry?

Q4) Name the plant tissue which helps in carrying the food to different parts.

Q5) Define the terms:

(a) semi-permeable membrane

(b) osmosis.

Q6) Under what conditions do plant transpire (a) more quickly and (b) most slowly?

Q7) Given here is an enlarged diagram of a part of the root. Draw arrows on the diagram to show the movement of water passing through different parts.

Q8) Why is the structure of the root hair quite suitable for absorbing water from the soil?

Q9) Briefly explain, how transpiration helps in upward conduction of water in plants?

Q10) How does temperature, light intensity and wind affect transpiration?

Q11) The set up shown alongside was kept in sunlight for an hour. It was observed that drops of water appeared on the inside of the polythene bag.

(a) Name process which is being demonstrated.

(b) Why was the pot and its soil left uncovered by the polythene bag?

(c) Why was the pot left in the sunlight?

(d) Suppose the pot in this experiment was placed inside a dark room instead of placing it in sunlight for some time. What difference will be noticed?

Q12) State whether the following statements are true or false. Rewrite the false statements correctly.

(a) Water absorption mainly occurs through the root-hair.

(b) Water enters the root-hair by osmosis.

(c) Water absorbed by the roots reaches the leaves and is used in producing food for the entire plant.

(d) A semipermeable membrane allows larger molecules to pass through but prevents the smaller ones.

(e) Transpiration is the loss of water from the roots of the plant.

(f) During transpiration, the leaves lose more water from their upper surface.

(g) Transpiration cools the plant when it’s hot outside.

Q13) Fill in the blanks:

1. Transportation in plants is carried out by a _______ system.

2. The upward movement of sap that contains water and minerals is called ______ of the sap.

3. Transpiration is more when the wind is blowing _____.

4. Most water gets evaporated from the plant from its ______.

5. Transpiration is reduced if the air is ______.

6. The leaves have more ______ on their lower surface.

Practice Question:

In an experimental set-up, a dye was placed at the bottom of a beaker filled with water as shown in figure A, below. After some time, the entire water in the beaker got coloured uniformly as shown in figure D.

(a) Name and define the phenomenon shown in the experiment.

(b) In all the four figures, two kinds of molecules are shown symbolically – larger and smaller. Which molecules are of the solute and which are of the solvent?

(c) If all the dark shaded molecules in A are tightly enclosed in a cell membrane, what will be the nature of movement of the molecules, if any?