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 water absorption and ascent of sap in plants active transport and passive transport types of plant transport atp

During phloem transportation sugar is moved in form of sucrose in to the companion cells and them into the living phloem sieve tube cells by -

  1. Passive transport

  2. Active transport

  3. Facilitated diffusion

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

Pholem is the food-conducting tissue.

The sugar sucrose is transported from the companion cells to the sieve tube by the mechanism for simple diffusion because of the concentration gradient.
The concentration of the sucrose is higher in the companion cells an lower in sieve tubes.
So, the correct option is 'Passive transport'

Multiple choice botany water absorption and ascent of sap in plants active transport and passive transport types of plant transport atp

Percentage of water left in the soil when a plant begins to wilt is known as

  1. Wilting coefficient

  2. pH value of soil

  3. Field capacity

  4. Water holding cpacity
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Water held tightly by soil particles around them is called as hygroscopic water. It is held in a very thin film and is not available to plants. Plants are able to absorb capillary water, which is present in the capillary spaces between soil particles. Run away water is also not available to plants. 

Field capacity denotes total water content in a field including hygroscopic water, capillary water and chemically bound water. 
The percentage of water left in soil when plants begin to wilt is called as wilting coefficient. At wilting coefficient soil contains hygroscopic and chemically bound water.

Multiple choice botany water absorption and ascent of sap in plants active transport and passive transport types of plant transport atp

In trees, death of protoplasts is essential for vital function such as

  1. Stomatal movements

  2. Food transport

  3. Water transport

  4. Both water and food transport
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Water transport is a physical process and not a physiological process. It does not require living cells and protoplasm. The driving force is the transpiration pull generated by loss of water through leaves. This is the reason why xylem tracheids and vessels are dead on maturity. Food transport is a physiological process and requires living cells similarly stomatal movement also is a physiological process and requires living cells.

Multiple choice botany water absorption and ascent of sap in plants active transport and passive transport types of plant transport atp

Sucrose moves into sieve tube elements by?

  1. Diffusion

  2. Endosmosis

  3. Active transport

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

The mechanism used for the translocation of sugars from source to sink is called the pressure flow hypothesis. As glucose is prepared at the source, it is converted to sucrose. This is moved into the companion cells and then into the living phloem sieve tube cells by active transport. Again active transport is necessary to move the sucrose out of the phloem sap and into the cells which will use the sugar converting it into energy. 


Hence, the correct answer is option C.

Multiple choice biology respiration in living organisms breathing in plants mode of respiration in plants process of respiration

Roots-respire through.

  1. Stomata

  2. Lenticels

  3. Spiracles

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

  • The roots of a plant take up air from the spaces between the soil particles.
  • Root hairs are in contact with the air in the soil particles. 
  • Oxygen from the air in soil particles diffuse into root hair and reach all the cells of the root where it is utilised in respiration. Hence, roots respire through air spaces.
So, the correct answer is 'air spaces'.

Multiple choice biology respiration in living organisms breathing in plants mode of respiration in plants process of respiration

Which of the following structures helps in the absorption of water from the soil?

  1. Root hair

  2. Root tip

  3. Stomata

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

While plants can absorb water from many sources the best place for this is the root system which is in contact with the soil where most of the water is found. The root system is usually extensive and has root hairs which help increase the surface area for water absorption. Water enters the root hair cells and then moves from cell to cell till it reaches the root cortex it goes on to the xylem vessels to be transported to the leaves.

So, the correct option is 'Root hair'.

Multiple choice biology respiration in living organisms breathing in plants mode of respiration in plants process of respiration

The plants absorbs air for respiration from

  1. Air spaces in the soil

  2. Stomata in leaves

  3. Ovary

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

In plants respiration also takes place through roots. In soil oxygenated air is present in air spaces between soil particles. This oxygen is absorbed into the roots by root hair present on the roots. The hairs of the roots are in direct contact with them. In fact, a root hair is a lateral tubular outgrowth of the outer epidermal cells of a root. The oxygen present in between the soil particles diffuse into the root hairs. From root hairs, oxygen is supplied to all the parts of roots for respiration. During respiration, oxygen is converted into carbon dioxide gas which is diffused in opposite direction i.e. out of the roots by the same root hairs which complete the process of respiration in roots.

So, the correct option is 'Air spaces in the soil'.

Multiple choice biology respiration in living organisms breathing in plants mode of respiration in plants process of respiration

Where do plant roots take up oxygen from?

  1. Atmospheric air

  2. Air spaces between soil particles

  3. Water in soil particles

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

Plant's roots are embedded into the soil. The soil has air spaces which allow the tip of the roots to take up oxygen and then this is transported to the other parts of the plant.

So the correct answer is 'Air spaces between the soil'.

Multiple choice botany root - external morphology zones of the root morphology of root root system in plants

Statement 1: Root cap protects the root meristem from the friction of the soil and its outer cells are continuously replaced by never ones.
Statement 2: The effect of the soil-friction damages the outer cells of root cap which are peeled off and replaced by new cells produced by root meristem. 

  1. Both statement 1 and 2 correct.

  2. Statement 1 is correct but statement 2 is incorrect.

  3. Statement 1 is incorrect but statement 2 is correct.

  4. Both statement 1 and 2 incorrect.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Both the statements are correct. So, the correct answer is (a).