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

Increase in temperature and velocity of wind cause an increase in transpiration initially but later it slows down because

  1. of closure of stomata

  2. water is not made available to the plant further

  3. the air around the plant becomes humid

  4. of mechanical disturbances

  5. of chemical disturbances
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Increase in temperature and velocity of wind cause an increase in transpiration initially but later it slows down because of closure of stomata.

Multiple choice

The spraying of phenyl mercuric acetate on leaves

  1. increases transpiration

  2. reduces transpiration

  3. increases the rate of photosynthesis

  4. reduces the rate of photosynthesis

  5. causes guttation
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The spraying of phenyl mercuric acetate on leaves reduces transpiration.

Multiple choice

In which of the following plants would the metabolism be hindered, if the leaves are coated with wax on their upper surface?

  1. Hydrilla

  2. Pistia

  3. Lotus

  4. Vallisneria

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

In lotus plant, the metabolism might be hindered if the leaves are coated with wax on their upper surface. The reason is that the exchange of gases takes place through the leaf surface, present on the upper surface. Since the upper surface of the leaf is above water, hence high frequency of stomata is present on the upper surface only. So, when the upper surface is coated, the gas exchange and other activities will eventually stop.

Multiple choice

Root pressure is the maximum when

  1. transpiration is high and absorption is very low

  2. transpiration is very low and absorption is high

  3. transpiration is very high and absorption is low

  4. transpiration is very high and absorption is also high

  5. transpiration is low and absorption is also low
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Root pressure is the maximum when transpiration is very low and absorption is high.

Multiple choice

Which of the following processes is/are performed by plants?

  1. Transpiration
  2. Respiration
  3. Guttation
  4. Photolysis

  1. Only 1 and 2

  2. Only 1, 2 and 3

  3. Only 1 and 3

  4. All of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

(i) Transpiration is the loss of water from plants in the form of water vapour.

(ii) Plants respire during night time, which involves intake of oxygen and give out carbon dioxide. Plants also respire during day time, which is called photorespiration (but in lesser extent).

(iii) Guttation is the loss of water in the form of water droplets. (iv) Photolysis is the breakdown of water molecules to release oxygen during photosynthesis.
Multiple choice

Which of the following is/are the function(s) of transpiration in plants?

  1. Upward movement of water from roots to leaves
  2. To provide cooling effect to plant
  3. To maintain the balance of water in plant body
  4. To absorb nutrients from soil

  1. Only 1

  2. Only 2

  3. Only 1, 2 and 3

  4. Only 2 and 4
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Statement 1 is correct. Transpiration is responsible for the movement of water from roots to leaves by ascent of sap.

Statement 2 is correct. Transpiration provides cooling effect to plants because the escaping water vapour carries away the heat energy.

Statement 3 is correct. Transpiration maintains the level of water in plant body.

Statement 4 is wrong. Plants absorb nutrients from soil by root pressure. 

Multiple choice

Under which of the following conditions will plants undergo wilting (loss of rigidity)?

  1. High temperature
  2. High humidity
  3. Heavy rainfall

  1. Only 1

  2. Only 2

  3. Only 3

  4. All of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Plants will undergo wilting in case of deficiency of water in the plant body.

1. In case of high temperature, the transpiration rate is more than than absorption of water, which causes water deficiency. 2. In case of high humidity, the transpiration rate decreases and it does not cause deficient gradient. 3. Similarly in case of heavy rainfall, the transpiration rate decreases and it does not cause deficient gradient.

Multiple choice

What are submerged plants?

  1. Plants that float on the surface of water

  2. Plants which are fixed into the bottom of the pond by their roots

  3. Plants that eat insects

  4. Plants that move along with water current and do not break

  5. Plants that grow in hot and dry desert
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Plants that move along with water current and do not break are the submerged plants.These plants have small and narrow leaves. They can withstand the strong water currents. They do not have stomata. They breathe through their body surface. They make their food using the carbon dioxide that is dissolved in water.

Multiple choice

Why do water plants like hydrilla have small leaves?

  1. To get enough sunlight for photosynthesis

  2. So that they do not break by the strong current of water

  3. Small leaves help them to get minerals from the water.

  4. To prevent loss of water from leaves

  5. So that they can breathe properly
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Hydrilla is a freshwater, aquatic plant that has small narrow leaves. These leaves move along with the water current and do not break. They can withstand the strong currents of water.

Multiple choice

Why do some plants shed their leaves in winter?

  1. They do not need leaves any more.

  2. Leaves fall off because of low temperature.

  3. Leaves cannot make their food as sunlight is low.

  4. Leaves protect their roots of the plant from winter

  5. Leaves provide nutrients to the plant by mixing in the soil.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Some trees shed their leaves in winter when season changes. Fresh new leaves appear. This happens because leaves cannot make their food in winter as sunlight is less. So, they let their leaves fall off at one time and are called deciduous plants. Examples: oak, cherry, etc.

Multiple choice

Which of the following statements is not correct?

  1. The roots of a plant usually grow underground.

  2. The roots support the plant by fixing it to the ground.

  3. The roots absorb water and nutrients from the soil.

  4. The roots of leguminous plants are habitat for some organisms.

  5. Ginger is an example of root.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Ginger is the stem of its plant. So, this statement is incorrect and the required answer.

Multiple choice

Which of the following statements is incorrect?

  1. Branches, leaves, fruits and flowers grow on stems of plants.

  2. Stems of a plant provide support to the plant.

  3. Stems transport water and minerals from the roots to various parts of a plant.

  4. Stems of a plant bend themselves in the direction opposite to sunlight.

  5. The food made in the leaves is transported to other parts of a plant through stems.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Stems of a plant bend themselves towards the direction of sunlight.