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 botany transpiration guttation excretion in plants long distance transport of water

The continuous excretion of watery substance from stump of a well watered pot plant after cutting off the shoot slightly above the base is due to

  1. Root pressure

  2. Guttation

  3. Transpiration

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

Root pressure is osmotic pressure within the cells of a root system. Root pressure is generated by active uptake of minerals by roots, which lowers water potential of root cells and water flows inside the cells along its concentration gradient. Thus, on the cutting of shoot, excretion of watery substance from cut side occurs.

Multiple choice botany transpiration guttation excretion in plants long distance transport of water

The loss of water in the form of water drops is known as

  1. Transpiration

  2. Respiration

  3. Guttation

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

Transpiration is the process where plants absorb water through the roots and then give off water vapor through pores in their leaves.

Respiration  is a process in which living organisms produces energy, with the intake of oxygen and the release of carbon dioxide from the oxidation of complex organic substances.
Guttation is the loss of water in the form of water droplets from hydathodes (small pores) on the leaf margin of a plant.
The passage of material through a semi-permeable membrane from a region of higher to a region of lower concentration, especially the passage of water through a cell membrane into the surrounding medium, is called exosmosis. 
Thus, the correct answer is option (C).

Multiple choice botany transpiration guttation excretion in plants long distance transport of water

Guttational drop comprises 

  1. Simple water

  2. Water and various salts dissolved in it

  3. Water and inorganic salts

  4. Water and organic cells
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Guttation is the loss of water in the form of droplets along the margin and tips through special structures called hydathode. The guttational drops comprise of water various salts dissolved in it. 
Thus, the correct answer is option (B). 

Multiple choice botany transpiration guttation excretion in plants long distance transport of water

Guttation is from

  1. Uninjured edges of leaves near vein endings

  2. Epidermal layers of leaf surface

  3. Injured edges of leaves

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

Guttation is the loss of water in the form of liquid from the uninjured margins of the leaves is called guttation. The pores are known as hydathodes. The level of soil moisture is high which creates greater root pressure. This root pressure creates a force which allows exudation of water from the tips. It is favored when the transpiration is suppressed and the relative humidity is high
Thus the correct answer is option (A). 

Multiple choice botany transpiration guttation excretion in plants long distance transport of water

Water exudation through hydathodes is 

  1. Guttation

  2. Transpiration

  3. Hydrolysis

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

Water exduation through hydathodes is known as guttation. Guttation is the process of loss of impure water (a dilute solution of different organic and inorganic substances) from plant infact, mostly from margins of leaves. It occurs when transpiration rate is very low as compared to rate of water absorption. Due to this root pressure is developed and water is pushed out through specialized pores at vein endings called hydrathodes. Each hydrathode is made up of group of loosely arranged achlorophyllous or colorless and parenchymatous cells called epithem. These cells help in absorbing a good percentage of inorganic and organic solutes present in the exudate. 

So, the correct answer is option A.

Multiple choice botany transpiration guttation excretion in plants long distance transport of water

Guttation occurs in well-watered herbaceous plants of well-drained soils during

  1. Evening

  2. Morning

  3. Day

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

Guttation is the moisture emitted by plants during night time.

Mainly it is caused by due to root pressure. At night time in absence of transpiration water will get accumulated in roots and it will cause root pressure due to high soil moisture level. in this condition, plants emit water in form of droplets it is called as guttation. So droplets are emitted during morning time in well-watered herbaceous plants of well-drained soil.
So the correct answer is 'Morning'.

Multiple choice botany transpiration guttation excretion in plants long distance transport of water

Water potential in leaf tissue is 'positive' (near zero) during 

  1. Low transpiration

  2. Excessive absorption

  3. Excessive transpiration

  4. Guttation
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Transpiration is the process of evaporation of water from the upper surface of the leaves.
(A)Low transpiration indicates the low level of water evaporated and the water potential is negative.
(B)Excessive absorption indicates the entering of the molecule to bulk phase and the water potential is negative.
(C)Excessive transpiration indicates the high level of water evaporated and the water potential is negative.
(D)Guttation occurs due to root pressure. It is the loss of water through leaves in the absence of photosynthesis. Due to root pressure water moves upwards and at this point, the amount of water is more in leaves than the atmosphere so water potential is positive.
So, the correct answer is 'Guttation'.
Multiple choice botany transpiration guttation excretion in plants long distance transport of water

Guttation is due to 

  1. Negative root pressure

  2. Positive root pressure

  3. Transpiration

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

Root pressure is the pressure caused due to the accumulation of water in the root region. It is caused in the absence of transpiration so, due to excess water in the plant, it exudes water through leaves in morning time it is called guttation.

So, the correct answer is 'Positive root pressure'.

Multiple choice botany transpiration guttation excretion in plants long distance transport of water

Guttation occurs when

  1. Wind velocity is high

  2. Humidity increases

  3. Root pressure is less and transpiration rate is more.

  4. Root pressure is more and transpiration rate is less.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Guttation is the process of secretion of the droplet of water from the pores of the plant. It occurs when the root pressure goes high and so the suction force gets increased. Also, when the rate of transpiration, that is the rate of evaporation of water from the leaves goes low, the guttation takes place.

So, the correct answer is 'Root pressure is more and the transpiration rate is less'.

Multiple choice botany transpiration guttation excretion in plants long distance transport of water

Process of water exudation from hydathodes is known as

  1. Guttation

  2. Transpiration

  3. Evaporation

  4. Bleeding
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Guttation is the process of loss of impure water from plant infact, mostly from margins of leaves. It occurs when transpiration rate is very low as compared to rate of water absorption. Due to this root pressure is developed and water is pushed out through specialized pores at vein endings called hydathodes. Each hydathode is made up of group of loosely arranged achlorophyllous or colourless and parenchymatous cells called epithem. These cells help in absorbing a good percentage of inorganic and organic solutes present in the exudate. Thus guttation is due to the positive pressure in the xylem developed due to the root pressure.
So, the correct answer is option A.
Multiple choice botany transpiration guttation excretion in plants long distance transport of water

Water lost through the process of guttation is in

  1. Liquid form containing dissolved minerals

  2. Liquid form without dissolved minerals

  3. Vapour form with minerals

  4. Vapour form without minerals
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Water lost through guttation is in the form of water droplets which also take minerals along with them. Since it is in liquid form, it can dissolve minerals in too.

It is not in the form of vapours as in the case of transpiration. The vapours flow not take minerals with them.
So the correct answer is 'Liquid form containing dissolved minerals'.

Multiple choice botany transpiration guttation excretion in plants long distance transport of water

The process of release of water through and intact plant is called.

  1. Guttation

  2. Exudation

  3. Oozing

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

Guttation is the process of water droplet release through hydathodes (specialized pores) in intact plants, typically occurring when transpiration is low and root pressure is high. This happens at night or early morning. Option B is the general term but guttation is more specific for intact plants.

Multiple choice botany transpiration guttation excretion in plants long distance transport of water

Loss of water from tip of leaves is called 

  1. Guttation

  2. Transpiration

  3. Evaporation

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

Transpiration is the process in which water vapours are released from the stomata.

Respiration is a metabolic process in which oxygen is used to break down food and carbon dioxide and energy are released.
Evaporation is the process of conversion of liquid water into water vapour.
Guttation is the process of loss of water droplets from pores known as hydathodes and tips of leaves.
So the correct answer is 'Guttation'.

Multiple choice botany transpiration guttation excretion in plants long distance transport of water

Loss or excretion of water in the form of liquid droplets from the margins and tips of leaves is called

  1. Transpiration

  2. Guttation

  3. Bleeding

  4. Precipitation
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
The loss or excretion of water in the form of liquid droplets from the leaves and other parts of uninjured or intact plant is called guttation. It was first studied by Bergerstein in 18871887. All plants do not show guttation. It is restricted to about 345345 genera of herbaceous and some woody plants. Common examples are garden nasturtium, oat and other cereals, balsam, tomato, cucurbits, Guttation takes place through special structures called hydathodes. They are usually found on the margins and tips of the leaves.
So, the correct answer is 'Guttation'.
Multiple choice botany transpiration guttation excretion in plants long distance transport of water

Stomata : Transpiration : : Hydathode : ___________.

  1. Guttation

  2. Root pressure

  3. Bleeding

  4. Oozing
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The process of exudation of liquid drops from the edges of leaves is called guttation. Usually it occurs through stomata-like pores called hydathodes. It is this process by which fully turgid plant remove extra water. The cause of guttation is mainly root pressure(when the root pressure is high and rate of transpiration is low, guttation takes place). Hydathodes are stomata-like pores, generally present at the tips or margins of leaves of those plants that grow in moist shady places(e.g., Tropaeolum). So, the correct answer is 'Guttation'.