Biology

Plant Transport and Physiology

2,012 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 water potential water potential and pressure plant water relation transport in plants biology

Choose the correct answers from the alternatives given :
In which one of the following processes the phenomenon of osmosis is not involved

  1. Water entering a mesophyll cell from xylem vessel element

  2. Water passing from root hair to adjacent cells

  3. Water from soil entering a root hair

  4. Water passing up a xylem vessel element to xylem vessel above it
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Osmosis is the movement of solvent from its higher concentration to its lower concentration across a semipermeable membrane. Movement of water through xylem element to xylem vessels above it occurs due to the cohesive force between the water molecules, suction pressure and transpiration pull.


So the correct answer is "Water passing up a xylem vessels element to xylem vessel above it".

Multiple choice biology plant growth growth rates and conditions for growth population ecology growth and development

Ectomycorrhiza is an association of ________.

  1. Bacterial and plant roots

  2. Cyanobacterial and plant root

  3. Fungi and plant roots

  4. Bacteria and fungi
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Ectomycorrhiza is a symbiotic association between fungi and the roots of higher plants, where the fungal hyphae form a sheath around the root and inter-cellularly network in the cortex.

Multiple choice biology plant growth growth rates and conditions for growth population ecology growth and development

Incorrect about geometrical growth

  1. After mitosis both daughter cells retain the capacity of division

  2. Growth pattern follows sigmoid curve

  3. Less common than arithmetic growth in the plants

  4. Growth rapidly increases
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In geometrical growth both the progeny cells following mitotic cell division retain the ability to divide and continue to do so. However, with a limited supply of nutrients, the growth becomes slow which lead to the stationary stage. A sigmoid curve is the characteristic of organism living is the natural environment.

So the correct option is 'growth rapidly increases'

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 vapours from the living tissues of aerial plant parts is called _________________.

  1. Transpiration

  2. Guttation

  3. Bleeding

  4. Precipitation
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The loss of water in the vapour form from the exposed parts of a plant is called transpiration. The loss of water due to transpiration is quite high. It is 22 litre per day in sunflower, 36−4536−45 litres in apple and upto 11 tonne per day in elm tree.

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

Leaf pores/ stomata help in _______.

  1. Intake of $CO _2$ during photosynthesis
  2. Release of $O _2$ during photosynthesis

  3. Release of water vapour during transpiration

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

Stomata has 3 major functions:

1. Transpiration causing release of water vapour
2. Intake of carbon dioxide during photosynthesis
3. Release of oxygen during photosynthesis
So the correct answer is 'All of these'.

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 mechanism of transpiration in plants is performed by:

  1. Stem

  2. Only leaves

  3. Flowers

  4. All of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Water loss by transpiration may take place from any part of the plant exposed to external atmosphere. It occurs, however, principally from the leaves and is known as foliar transpiration. Only, a relatively small quantity of water is transpired from the stem and is called cauline transpiration.
So, the correct answer is 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 process of transpiration in plants helps in

  1. Opening of stomata.
  2. Absorption of $CO _2$ from atmosphere.

  3. Upward conduction of water and minerals.
  4. Absorption of $O _2$ from atmosphere.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
In plants transpiration develops a transpiration pull that pulls water and minerals upwards from root towards leaves
So, the correct answer is 'Upward conduction of water and minerals'
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 force arises between the water molecules of leaves due to transpiration?

  1. Cohesive forces

  2. Pressure force

  3. Suction force

  4. Adhesive force
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A.Cohesive force – force of attraction present between the water molecules is called cohesive force. Due to this, water column maintains tensile strength.

B.Pressure force – force developed to accumulation of pressure.

C.Suction force – force exists in the sucking of water.

D.Adhesive force – force of attraction exists between the water molecules and walls of the vessels is called adhesive force. Due to this, capillarity exists in the water column.

So, the correct option is ‘cohesive force’.

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 process of transpiration in plants helps in the

  1. Opening of stomata

  2. Closing of stomata

  3. Upward conduction of water and minerals

  4. Both B and C
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Transpiration is the loss of water by the stomatal openings of the aerial parts of the plant. This helps in the upward movement of water and minerals from the roots to the leaves by a cohesion-adhesion mechanism. 

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 process of transpiration is a

  1. Diffusion

  2. Osmosis

  3. Active transport

  4. facilitated Diffusion
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
During the process of transpiration, the water moves up the xylem vessels to the leaves through diffusion. Diffusion takes place because there is a difference in water potential between water in the xylem vessel and the leaf (as water is transpiring out of the leaf). There is also a pressure change between the top and bottom of the xylem vessels, due to water loss from the leaves. This reduces the pressure of water at the top of the vessels. This means water moves up the vessels and then out of the leaves through diffusion.
So, the correct option is 'Diffusion'.
Multiple choice botany breath and blood of life stomata and transpiration transport in organisms long distance transport of water different types of circulatory systems

Water movement against gravity is caused by?

  1. Imbibition

  2. Transpiration

  3. Osmosis

  4. Diffusion
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Water movement against gravity is caused by transpiration. Transpiration is the process by which water is carried through plant roots to small pores of the leaves, where it changes to vapor and is released to the atmosphere. The mechanism of transport of water against gravity is by cohesive forces of water molecules. Water molecules cohere and are pulled up the plant by the tension, exerted by evaporation at the leaf surface. 

Thus, 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

The shade of the tree is often cooler than exposed atmosphere, because of

  1. Photosynthesis

  2. Respiration

  3. Transpiration

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

Transpiration is a process of loss of water from a plant in vapour form. One of the benefits of transpiration is that it causes surface cooling because evaporation of water requires energy. Consumption of energy leads to a cooling effect on the leaf surface. Also because of more water vapour content in shade, a tree shade is cooler than area exposed to sunlight. 

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.