Question 91:
What process helps to maintain the plant’s internal water balance?
A) Photosynthesis
B) Respiration
C) Transpiration
D) Fermentation
Answer: C) Transpiration
Explanation: Transpiration helps regulate the plant’s internal water balance by controlling water loss through stomata.
Question 92:
Which plant hormone is primarily responsible for cell elongation and growth?
A) Auxin
B) Cytokinin
C) Ethylene
D) Abscisic acid
Answer: A) Auxin
Explanation: Auxins promote cell elongation, allowing for growth in stems and roots.
Question 93:
The Casparian strip is located in which part of the root?
A) Epidermis
B) Cortex
C) Endodermis
D) Vascular cylinder
Answer: C) Endodermis
Explanation: The Casparian strip is a band of cell wall material in the endodermis that helps regulate the flow of water and minerals into the vascular tissue.
Question 94:
Which of the following best describes the role of mycorrhizae?
A) They provide structural support to plants.
B) They enhance nutrient and water absorption.
C) They protect plants from herbivores.
D) They are responsible for photosynthesis.
Answer: B) They enhance nutrient and water absorption.
Explanation: Mycorrhizae are symbiotic associations between fungi and plant roots that increase the surface area for water and nutrient absorption.
Question 95:
What is the main function of the root hairs?
A) Photosynthesis
B) Nutrient absorption
C) Mechanical support
D) Water storage
Answer: B) Nutrient absorption
Explanation: Root hairs increase the surface area of roots, enhancing the plant’s ability to absorb water and nutrients from the soil.
Question 96:
Which of the following adaptations would help a plant survive in a desert environment?
A) Large leaf area
B) Deep taproots
C) Open stomata during the day
D) Thin cuticle
Answer: B) Deep taproots
Explanation: Deep taproots allow plants to access water from deeper soil layers, making them better adapted to arid conditions.
Question 97:
What effect does increased temperature have on the rate of transpiration?
A) It decreases the rate of transpiration.
B) It has no effect on transpiration.
C) It increases the rate of transpiration.
D) It depends on humidity levels.
Answer: C) It increases the rate of transpiration.
Explanation: Higher temperatures increase the rate of evaporation of water from leaf surfaces, leading to an increase in transpiration.
Question 98:
The process by which nutrients are moved from the soil into the root cells is called:
A) Diffusion
B) Filtration
C) Active transport
D) Osmosis
Answer: C) Active transport
Explanation: Active transport allows roots to absorb essential nutrients from the soil against their concentration gradient.
Question 99:
Which of the following is a primary source of energy for the process of transpiration?
A) Sunlight
B) Wind
C) Soil moisture
D) Root pressure
Answer: A) Sunlight
Explanation: Sunlight provides the energy needed for photosynthesis, which in turn drives transpiration by creating a water vapor gradient.
Question 100:
Which of the following structures regulates water loss in plants?
A) Phloem
B) Xylem
C) Stomata
D) Cuticle
Answer: C) Stomata
Explanation: Stomata are openings on leaf surfaces that regulate gas exchange and water loss, playing a critical role in maintaining plant hydration.
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