Absorption by Roots & Transpiration Quiz - ICSE Class 10 Biology

Free practice quiz: Absorption by Roots & Transpiration (ICSE Class 10 Biology). 35 multiple-choice questions with answers and explanations. Play online, no sign-up needed.

This ICSE Class 10 Biology practice quiz has 35 multiple-choice questions on Absorption by Roots & Transpiration, and 35 of them come with an explanation. Try the 5 sample questions below (tap an option to check yourself), then play the full quiz online. No sign-up needed.

Sample questions

1. A plant is subjected to an environment with extremely low humidity and high wind speeds. Which of the following adaptations would be most crucial for its survival to minimize water loss through transpiration?

   1. Large, broad leaves with numerous stomata
   2. Thick cuticle and sunken stomata
   3. Extensive root system with numerous root hairs
   4. Presence of hydathodes
   Show answer

   Answer: B. Thick cuticle and sunken stomata

   A thick cuticle acts as a barrier to water loss, and sunken stomata create a humid microenvironment around the stomatal pore, reducing the water potential gradient and thus transpiration. Large leaves and numerous stomata increase transpiration. Extensive root systems are for absorption, not reducing loss. Hydathodes are involved in guttation, not stomatal transpiration.

2. The rate of transpiration can be significantly reduced by applying a thin layer of oil on the surface of leaves. What is the primary reason for this reduction?

   1. The oil increases the water potential of the leaf.
   2. The oil blocks the stomatal pores, preventing gas exchange and water vapor diffusion.
   3. The oil directly inhibits the activity of xylem vessels.
   4. The oil stimulates the closure of guard cells.
   Show answer

   Answer: B. The oil blocks the stomatal pores, preventing gas exchange and water vapor diffusion.

   Transpiration primarily occurs through stomata. A layer of oil effectively seals these pores, preventing the outward diffusion of water vapor and also inhibiting the inward diffusion of CO2 needed for photosynthesis. It doesn't directly affect xylem or guard cell function in this manner.

3. The primary function of root hairs in a plant is:

   1. To anchor the plant firmly in the soil.
   2. To absorb water and dissolved minerals from the soil.
   3. To store food reserves for the plant.
   4. To transport sugars from the leaves to the roots.
   Show answer

   Answer: B. To absorb water and dissolved minerals from the soil.

   Root hairs are thin, hair-like extensions of epidermal cells in the root. They greatly increase the surface area of the root, maximizing the absorption of water and dissolved mineral nutrients from the soil.

4. If a plant leaf is observed to have wilting symptoms, but the surrounding soil is moist, what could be the primary reason?

   1. Excessive absorption of mineral salts.
   2. High rate of transpiration exceeding water absorption.
   3. Low rate of photosynthesis.
   4. Reduced root pressure.
   Show answer

   Answer: B. High rate of transpiration exceeding water absorption.

   Wilting occurs when water loss from the plant (transpiration) is greater than water uptake by the roots. Even if the soil is moist, if transpiration is very high (e.g., due to hot, dry, windy conditions), the plant can wilt because it cannot absorb water fast enough to replace the lost water.

5. Which of the following is a direct consequence of reduced stomatal aperture?

   1. Increased rate of photosynthesis.
   2. Increased absorption of water by roots.
   3. Decreased rate of transpiration.
   4. Increased uptake of mineral ions.
   Show answer

   Answer: C. Decreased rate of transpiration.

   The stomatal aperture is the opening size of the stoma. Reducing this aperture limits the diffusion of water vapor out of the leaf, thereby decreasing the rate of transpiration. It also limits CO2 uptake, affecting photosynthesis.

More questions in this quiz

Answers and explanations are in the full quiz.

1. Consider a situation where a plant's xylem vessels are blocked. Which process will be most directly and severely affected?
2. When a plant leaf is placed in a solution with a very low water potential (e.g., concentrated salt solution), what will happen to the plant cells?
3. Mineral ions are absorbed by root hairs. This absorption can occur against a concentration gradient. What is the primary mechanism responsible for this process?
4. The Casparian strip in the endodermis of plant roots is a band of suberin that prevents water and dissolved solutes from moving through the cell walls and intercellular spaces. What is its primary function?
5. Which of the following is a consequence of reduced root pressure in a plant?
6. When transpiration exceeds water absorption, the plant wilts. This wilting is primarily due to:
7. During water absorption by roots, the initial movement of water into the root hair cells is driven by:
8. The presence of aquaporins in the plasma membranes of root cells facilitates:
9. Which process is responsible for the bulk flow of water from the xylem in the leaf veins into the mesophyll cells?
10. Consider a plant cell placed in a hypotonic solution. What is the most likely outcome?
11. The cohesion-tension theory explains the ascent of sap. Cohesion refers to:
12. Which of the following processes is directly responsible for the movement of water from the soil into the root hairs, even when soil water potential is higher than root hair water potential?
13. Which of the following environmental factors has the most significant *inhibitory* effect on the rate of transpiration?
14. If the stomata of a plant are artificially sealed, how will this most likely affect the plant?
15. The movement of water across the root cortex to the xylem can occur via the apoplast pathway. This pathway involves movement:
16. In the process of photophosphorylation, light energy is ultimately used to:
17. Adhesion, in the context of the cohesion-tension theory, refers to:
18. What is the primary role of the endodermis with its Casparian strip in root water absorption?
19. Which of the following is a characteristic feature of stomata that contributes to efficient gas exchange while minimizing water loss?
20. In the cohesion-tension theory, tension is created by:
21. The mesophyll cells are the primary site of photosynthesis in a leaf. Water moves from the xylem into these cells primarily by:
22. If a plant is grown in a nutrient-poor soil solution with very few mineral ions, what is the most likely consequence for the root hair cells' absorption process?
23. The loss of water vapor from a plant through lenticels, rather than stomata, is known as lenticular transpiration. Lenticular transpiration accounts for:
24. What is the role of the xylem parenchyma in the root?
25. Which type of cell in the xylem is primarily responsible for the transport of water and minerals in mature, functional xylem?
26. When a plant experiences prolonged water scarcity, its leaves may show signs of wilting. This is primarily because:
27. Which process ensures that water moves from the soil into the root hair cells even if the concentration of solutes in the soil is very low?
28. During intense sunlight and high temperatures, stomata may partially close. This response is primarily an adaptation to:
29. The symplastic pathway for water movement in roots involves:
30. Which statement accurately describes the relationship between transpiration and the ascent of sap in tall plants?

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