Tag: botany

Questions Related to botany

Leaf pores/ stomata help in _______.

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

  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

Show answer
Correct Option: D
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'.

The mechanism of transpiration in plants is performed by:

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

  1. Stem

  2. Only leaves

  3. Flowers

  4. All of these

Show answer
Correct Option: D
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.

The process of transpiration in plants helps in

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

  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.

Show answer
Correct Option: C
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'

Which force arises between the water molecules of leaves due to transpiration?

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

  1. Cohesive forces

  2. Pressure force

  3. Suction force

  4. Adhesive force

Show answer
Correct Option: A
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’.

The process of transpiration in plants helps in the

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

  1. Opening of stomata

  2. Closing of stomata

  3. Upward conduction of water and minerals

  4. Both B and C

Show answer
Correct Option: C
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. 

Which is used to measure the rate of transpiration?

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

  1. Atmometer

  2. Psychrometer

  3. Potometer

  4. Porometer

Show answer
Correct Option: C
Explanation:

Atmometer is a device used to measure the rate of water evaporation from a wet surface to the atmosphere and can be used to measure the rate of evapotranspiration. 

A psychrometer is a device used to measure the rate of relative humidity in the atmosphere. 
Potometer is a device used to measure the rate of water uptake by plants  porometer is a device used to measure the area of the stomatal opening of leaves.
 So, the correct answer is 'Potometre'.

The process of transpiration is a

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

  1. Diffusion

  2. Osmosis

  3. Active transport

  4. facilitated Diffusion

Show answer
Correct Option: A
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'.

Water movement against gravity is caused by?

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

  1. Imbibition

  2. Transpiration

  3. Osmosis

  4. Diffusion

Show answer
Correct Option: B
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.

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

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

  1. Photosynthesis

  2. Respiration

  3. Transpiration

  4. Guttation

Show answer
Correct Option: C
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. 

Silicon emulsions are

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

  1. Antitranspirants

  2. Antirespirants

  3. Hormones

  4. None of these

Show answer
Correct Option: A
Explanation:

Antitranspirants are substances that are applied to the leaves to reduce transpiration. They are used on trees, cut flowers and shrubs. They reduces transpiration in fruit plants like apples, pears, orange, crop plants like cotton, tea, roses, tuber crops like potato, carrot and vegetable plants like chillies, tomato, cabbage. These are also used to protect plants from drying out too quickly. Various antitranspirants include abscisic acid (ABA), aspirin, silicon emulsions, plastics, waxes.

Thus, the correct answer is option A.