Biology

Plant Transport and Physiology

1,834 Questions

Access a comprehensive set of questions on plant transport mechanisms and physiological adaptations. Topics include water movement, translocation of food, and plant responses to external stimuli. These biology questions are essential for medical entrance exams and other science competitive tests.

Xylem and phloem transportTranspiration and evaporationPlant adaptationsGeotropic and phototropic responsesWater absorption by rootsRespiration in roots

Plant Transport and Physiology Questions

Multiple choice botany breath and blood of life stomata and transpiration transport in organisms long distance transport of water different types of circulatory systems

The loss of water from the plants is known as

  1. Respiration

  2. Transpiration

  3. Replication

  4. Ascent of sap
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Transpiration is the process by which moisture is carried through plants from roots to small pores on the underside of leaves, where it changes to vapor and is released to the atmosphere. Transpiration is essentially evaporation of water from plant leaves. Transpiration also cools plants, changes osmotic pressure of cells and enables mass flow of mineral nutrients and water from roots to shoots.

Therefore, the correct answer is option B.

Multiple choice botany breath and blood of life stomata and transpiration transport in organisms long distance transport of water different types of circulatory systems

Absorption of water is increased when

  1. Transpiration is increased.

  2. Photosynthesis is increased.

  3. Respiration is increased.

  4. None of the above.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

According to the transpiration pull theory, loss of water from aerial parts due to transpiration is a physical process and the loss of water generates the pulling force. Water is present as a continuous column in vascular tissues due to cohesive and adhesive forces. The loss of water due to transpiration is equal to the amount of water absorbed from the soil. More the transpiration loss of water, more the absorption of water from the soil and vice versa.

Multiple choice botany breath and blood of life stomata and transpiration transport in organisms long distance transport of water different types of circulatory systems

For plants, transpiration is

  1. Not very important

  2. Important to some

  3. A necessary evil

  4. An important burden
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Transpiration generates tension in plants. This tension is the main pulling force, which pulls water to great heights in vascular plants. Thus, transpiration leads to the ascent of sap. Without transpiration, water and minerals will not rise from roots to aerial parts of plants and trees. 

At the same time, it is essentially a wasteful process. As much as 99 percent of water absorbed by a plant goes waste into the atmosphere. Thus, transpiration has been called as a necessary evil.

Multiple choice botany breath and blood of life stomata and transpiration transport in organisms long distance transport of water different types of circulatory systems

Wilting of a plant results from excessive

  1. Respiration

  2. Photosynthesis

  3. Absorption

  4. Transpiration
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Transpiration is a loss of water in vapour form stomata. The rate of transpiration depends on a number of factors, like carbon dioxide concentration, temperature, light, humidity etc. The most important factor which governs the rate of transpiration is the vapour pressure gradient, which exists between leaf mesophyll and atmosphere. It has been estimated that almost 99 percent of water absorbed by plants is lost in transpiration. As transpiration generates the tension, which is the most important force responsible for water absorption.

When excessive water is lost from the plant than can be absorbed from soil, plant shows wilting. In wilting leaves droop down and there is a general loss in turgidity of leaf cells.

Multiple choice botany breath and blood of life stomata and transpiration transport in organisms long distance transport of water different types of circulatory systems

Plants get rid of excess water by

  1. Photosynthesis

  2. Respiration

  3. Transpiration

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Plants produce carbon dioxide and water as respiratory waste products. Plants get rid of excess water by transpiration and guttation. Transpiration is evaporation of water from plant leaves by stomata.

Multiple choice botany breath and blood of life stomata and transpiration transport in organisms long distance transport of water different types of circulatory systems

Transpiration is

  1. The absorption of water and minerals by the roots of a plant.

  2. The movement of sap upward in a plant against the force of gravity.

  3. The loss of water and waste material through stomata and lenticels.

  4. The absorption of waste materials from the blood by nephrons.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Transpiration is the biological process where water is lost from the aerial parts of plants, primarily through stomata in leaves, in the form of water vapor.

Multiple choice botany breath and blood of life stomata and transpiration transport in organisms long distance transport of water different types of circulatory systems

Loss of water in the form of water vapour from plants to atmosphere is called as

  1. Photosynthesis

  2. Respiration

  3. Transpiration

  4. Excretion
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Transpiration is the process by which moisture is carried through plants from roots to small pores on the underside of leaves, where it changes to vapor and is released to the atmosphere. Transpiration is essentially evaporation of water from plant leaves. 

Therefore, the correct answer is option C.

Multiple choice botany breath and blood of life stomata and transpiration transport in organisms long distance transport of water different types of circulatory systems

Which of the following processes keeps the plant cool?

  1. Photosynthesis

  2. Transpiration

  3. Respiration

  4. Translocation
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Water moves from the soil into plant roots, up through the sapwood into the leaves. The water, warmed by the sun, turns into vapor (evaporates) and passes out through thousands of tiny pores (stomata) mostly on the underside of the leaf surface. This process is transpiration. It has two main functions: cooling the plant and pumping water and minerals to the leaves for photosynthesis. Photosynthesis, respiration and translocation can not keep the plant cool. Therefore, the correct answer is option B.

Multiple choice botany breath and blood of life stomata and transpiration transport in organisms long distance transport of water different types of circulatory systems

Transpiration is a useful process as it is involved in 

  1. Loss of water

  2. Food translocation

  3. Ascent of water and minerals and reduce the impact of temperature on plants

  4. Growth and curvature of plants
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Transpiration is the process by which moisture is carried through plants from roots to small pores on the underside of leaves, where it changes to vapor and is released to the atmosphere. Transpiration is essentially evaporation of water from plant leaves. Translocation is not involved in food translocation and growth and curvature of plants.

Therefore, the correct answer is option C.

Multiple choice botany breath and blood of life stomata and transpiration transport in organisms long distance transport of water different types of circulatory systems

The loss of the water from leaves of plants is called as

  1. Translocation

  2. Trasnspiration

  3. Transfusion

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Transpiration is the process by which moisture or water is carried through plants from roots to small pores on the underside of leaves, where it changes to vapor and is released to the atmosphere. Transpiration is essentially evaporation of water from plant leaves. Transfusion and translocation do not involve the loss of water. 

Therefore, the correct answer is option B.

Multiple choice botany breath and blood of life stomata and transpiration transport in organisms long distance transport of water different types of circulatory systems

In both transpiration and evaporation, water is lost in the form of vapour yet they differ, because

  1. Both transpiration and evaporation are similar but the rate of water loss in transpiration is always more

  2. Frequency of water loss is different in both of them.

  3. Transpiration is a physical process and evaporation is a physiological process.

  4. Transpiration is a physiological process and evaporation is a physical process.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Transpiration is loss of water in vapor form, from living plant cells thus it is a physiological process while evaporation is loss of water from any free surface in vapor form, thus it is a physical process. 

Multiple choice botany breath and blood of life stomata and transpiration transport in organisms long distance transport of water different types of circulatory systems

Plants lose most of water through leaves by 

  1. Respiration

  2. Guttation

  3. Photosynthesis

  4. Transpiration
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Water is essential for plants, it absorbs water from the soil through roots. However, plants absorbs much water, but only a small amount of water is used for their growth and metabolism. Persisting 97 - 99.5% of absorbed water is lost by transpiration. Transpiration is the process of elimination water in the form of water vapour from the aerial parts such as leaves, flowers and stem.

So, the correct answer is option D.

Multiple choice botany breath and blood of life stomata and transpiration transport in organisms long distance transport of water different types of circulatory systems

The loss of water vapour by a plant is called as transpiration.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Water is transient in plants. Less than 1 per cent of the water reaching the leaves is used in photosynthesis and plant growth. Most of it is lost through the stomata in the leaves. This water loss in vapour form is known as transpiration.

Multiple choice botany breath and blood of life stomata and transpiration transport in organisms long distance transport of water different types of circulatory systems

The function of Anti-transpirants is:

  1. Reduce the rate of transpiration without affecting carbon assimilation

  2. Reduce the rate of transpiration affecting carbon assimilation

  3. Reduce the rate of transpiration affecting growth of plant

  4. Reduce the rate of transpiration affecting protein synthesis of plant
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Anti-transpirants are compounds applied to the leaves of plants to reduce transpiration. They are used to preserve and protect plants from drying out too quickly. They are also used to protect leaves from the salt burn and fungal diseases. Anti-transpirants reduce the stomatal opening and increase the leaf resistance to water vapour diffusion without affecting carbon dioxide uptake.

So, the correct answer is 'Reduce the rate of transpiration without affecting carbon assimilation'.

Multiple choice botany breath and blood of life stomata and transpiration transport in organisms long distance transport of water different types of circulatory systems

Which one of the following helps in the upward movement of water and dissolved minerals from the roots to the leaves through the stem ?

  1. translocation

  2. transportation

  3. transpiration

  4. transaction
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The continuous evaporation of water (or transpiration) from the cells of a leaf crates a kind of suction which pulls up water through the xylem vessles. Thus, transpiration helps in the upward movement of water and dissolved minerals from the roots to the leaves through the stem.