NIOS Biology Chapter 08 Absorption, Transport and Water Loss in Plants

NIOS Class 12 Biology Intext Solutions Chapter 8

INTEXT QUESTIONS 8.1

1. Define diffusion.

Ans: Diffusion is the intermingling of molecules of the same or different substances as a result of their random movement. It is dependent on the difference in concentration of molecules of different substances in the adjacent areas, and this difference is called the diffusion gradient.

2. Give one point of difference between osmosis and diffusion.

Ans: Diffusion does not require a membrane, while osmosis occurs across a semipermeable membrane. 

3. Name the process because of which crystals of KMnO₄ added to water makes it purple.

Ans: Diffusion

4. If blood cells are placed in salt water what will happen to them? Based on your answer state if salt solution is isotonic, hypotonic or hypertonic?

Ans: Water will move out from the blood cells, and they will shrink. Therefore, a salt solution is a hypertonic solution. 

5. When does plasmolysis occur in plant cells?

Ans: When a cell is placed in a hypertonic solution, i.e., when the concentration of the outer solution is higher than the cell sap, water from the cell moves out, resulting in shrinkage of the protoplasm in the centre of the cell. This phenomenon is known as plasmolysis.

6. Name the phenomenon which makes it difficult to close a wooden door after Monsoon?

Ans: Imbibition

INTEXT QUESTIONS 8.2

1. Which part of the plant absorbs water and minerals?

Ans: Root

2. What are plasmodesmata?

Ans: The cytoplasmic strands that connect one cell to the other one are known as plasmodesmata.

3. How does translocation occur in plants?

Ans: Through the phloem

4. What is the process of ascent of sap?

Ans: Movement of water and minerals from roots to leaves, that is, from the ground to the tip of the plant, is called ascent of sap. 

5. Which are three different forms in which water is present in the soil?

Ans: Gravitational, Hygroscopic, and capillary

INTEXT QUESTIONS 8.3

1. Name the pressure in guard cells responsible for opening and closing of stomata.

Ans: Turgor pressure

2. Mention the shape of guard cells in monocots and dicots.

Ans: 

• Dicot: Kidney-shaped
• Monocots: Dumb bell shaped

3. Give a point of difference between a stoma and a hydathode

Ans: 

• Stomata are pores on the leaf surface through which water diffuses as vapour
• Hydathodes are special pores in leaf margins through which water is lost as water droplets.

Additional Study Materials

• NIOS Class 12 Biology Terminal Questions Answers!
• Chapter 01 Intext Solutions
• Chapter 02 Intext Solutions
• Chapter 03 Intext Solutions
• Chapter 04 Intext Solutions
• Chapter 05 Intext Solutions
• Chapter 06 Intext Solutions
• Chapter 07 Intext Solutions