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 photosynthesis cam cycle cam plants photosynthetic cycle

Read the given statements and select the correct option. 
Statement 1 : Crassulacean acid metabolism occurs in succulent plants which grow in xeric conditions. 
Statement 2 : Stomata are generally sunken in succulent plants. 

  1. Both statements are correct

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

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

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

Crassulacean acid metabolism is a mechanism of photosynthesis involving double fixation of $CO _2$ which occurs in succulents belonging to Crassulaceae, Cacti, Euphorbias and some other plants of dry habitats. Here, the stomata remains closed during the daytime and opens only at night, e.g Sedum,Kalanchoe,Opuntia. Sunken stomata are deep seated stomata in which subsidiary cells lie above the guard cells.  So, the correct answer is 'Both statements are correct'.

Multiple choice botany photosynthesis cam cycle cam plants photosynthetic cycle

The plant adaptation not suitable for hot and dry climates is
I. CAM
II. Mycorrhizae
III. ${C} _{4}$ photosynthesis

  1. I only

  2. II only

  3. I and II

  4. I and III

  5. I, II, and III
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Spatial separation of carbon dioxide fixation and RUBISCO activity in mesophyll and bundle sheath cells of $C _4$ plants respectively avoids photorespiration by concentrating $CO _2$ in bundle sheath cells to scale down the oxygenase activity of RUBISCO and increase the RUBISCO efficiency. The increased RUBISCO efficiency allows higher rates of photosynthesis even when stomata are closed for the longer time as well as reduces photorespiration and water loss. CAM plants reduce water loss by opening the stomata at night only. Mycorrhizae are the symbiotic fungi that reside in roots of higher plants and increase soil fertility by nitrogen fixation; it does not impart any adaptive feature to plant to cope with hot and dry conditions. 

Therefore, the correct answer is option B.

Multiple choice botany photosynthesis cam cycle cam plants photosynthetic cycle

In kranz anatomy, the bundle sheath cells have

  1. thin walls, many intercellular spaces and no chloroplasts

  2. thick walls, no intercellular spaces and large number of chloroplasts

  3. thin walls, no intercellular spaces and several chloroplasts

  4. thick walls, many intercellular spaces and few chloroplasts.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
In Kranz anatomy, the bundle sheath cells are characterized by having a large number of agranal chloroplasts, thick walls impervious to gaseous exchange and no intercellular spaces.
Thus, the correct answer is 'thick walls, no intercellular spaces and large number of chloroplasts.'
Multiple choice chemistry nitrogen and sulfur sulfur and its oxides acid deposition natural resources- air, water and land
High concentration of $SO _2$ leads to stiffness of flower buds.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$SO _2$ is particularly poisonous to trees causing chlorosis and dwarfing. High concentration of $SO _2$ leads to stiffness of flower buds which then eventually fall off. Sulphur oxides $(SO _x)$ and sulphuric acid $(H _2SO _4)$ are related with the damage and destruction of vegetation, soil deterioration, construction material and watercourses.

Multiple choice bio-chemistry absorption by roots - the processes involved diffusion transport across membrane means of transport

Which of the following states the importance of diffusion?

  1. Helps in exchange of gases during respiration.

  2. Helps in exchange of gases during photosynthesis.

  3. Responsible for transpiration.

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
May be defined as the process of movement of gases, liquids or solutes from the region of higher concentration to the regions of lower concentration till the molecules are uniformly distributed throughout the available space dissolved sugars and ions of potassium and sodium can pass through cell surface membranes by diffusion. Waste products such as urea also pass out of the cell through its membrane by cell diffusion helps in exchange of gases during respiration and photosynthesis. It is also responsible for transpiration.
So, the correct answer is D.
Multiple choice bio-chemistry absorption by roots - the processes involved diffusion transport across membrane means of transport

Substances which can be moved through diffusion in plants are

  1. Ions

  2. Sugar

  3. Urea

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

Diffusion may be defined as the process of movement of gases. liquids or solutes from the region of higher concentration to the regions of lower concentration till the molecules are uniformly distributed throughout the available space dissolved sugars and ions of potassium and sodium can pass through cell surface membranes by diffusion. Waste products such as urea also pass out of the cell through its membrane by cell diffusion helps in exchange of gases during respiration and photosynthesis. It is also responsible for transpiration.

So, the correct answer is D.

Multiple choice bio-chemistry absorption by roots - the processes involved diffusion transport across membrane means of transport

Water in adjacent xylem moves into the phloem by process of :

  1. Simple diffusion

  2. Active transport

  3. Osmosis

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

Water is passively transported into the roots and then into the xylem. The forces of cohesion and adhesion cause the water molecules to form a column in the xylem. Water moves from the xylem into the mesophyll cells, evaporates from their surfaces and leaves by diffusion through the stomata. The increased solute concentration causes water to move by osmosis from the xylem into the phloem. The positive pressure that is produced pushes water and solutes down the pressure gradient. So, the correct answer is "Osmosis".

Multiple choice bio-chemistry absorption by roots - the processes involved diffusion transport across membrane means of transport

Aquatic plants lose most of their metabolic wastes by .......... process.

  1. Diffusion

  2. Osmosis

  3. Reverse osmosis

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

Aquatic plants lose most of their metabolic wastes by diffusion directly into the water, surrounding them as the concentration of that metabolic wastes is more in the cell as compared to the surroundings. They do not have to store the waste products as terrestrial plants do. Thus, the correct answer is option A.

Multiple choice coordination - the linking system movements in plants coordination in plants tropic and nastic movements in plants

Bending of stem towards light is

  1. Photoperiodism

  2. Heliotropism

  3. Photonasty

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

Heliotropism is a growth movement or bending of stem in the direction of the light. It is also called as solar tracking. Photoperiodism is the phenomenon in which various physiological reactions like flowering response to the relative length of dark or light periods. Photonasty is nastic movement of plant towards sunlight. Hydrotropism is a growth movement of plant part in response to water.

Thus, the correct answer is option B. 

Multiple choice biology life processes: control and coordination movements in plants coordination in plants tropic and nastic movements in plants

Bending of growing shoot towards sunlight is called

  1. Heliotropism

  2. Hydrotropism

  3. Photonasty

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

Heliotropism- The growth of plants or plants parts esp flowers in response to the stimulus or sunlight, so that they turn to face the sun. It enhances the photosynthesis process and increases growth rates.

So, the correct answer is 'Heliotropism'.

Multiple choice evs - i sources of water the lithosphere and the hydrosphere first aid safety and first aid

Which of the following is most important in water cycle?

  1. Transpiration through leaves

  2. Evaporation from the oceans

  3. Percolation of water into the ground

  4. Absorption of capillary water by plants
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Evaporation from the oceans is the most important in water cycle, because it comprises of the major part of global water cycle.

Multiple choice evs - i sources of water the lithosphere and the hydrosphere first aid safety and first aid

Water remaining in the soil after a plant has permanently wilted is

  1. Hygroscopic water

  2. Ground water

  3. Gravitational water

  4. Capillary water
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Hygroscopic water is the water held tightly by the soil and cannot be taken up by plant roots because this water forms very thin films around soil particles and is not available to the plant. Thus the correct answer is option A.
Multiple choice

The process by which plants lose water vapor through their leaves is called:

  1. Photosynthesis

  2. Respiration

  3. Transpiration

  4. Decomposition

  5. Pollination
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Transpiration is the process by which plants lose water vapor through their leaves, which helps to regulate their temperature and transport nutrients.

Multiple choice

What is the process of providing water to fruit trees called?

  1. Irrigation

  2. Fertilization

  3. Pruning

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

Irrigation is the process of providing water to fruit trees.

Multiple choice

The process by which plants absorb water and nutrients from the soil is known as:

  1. Transpiration

  2. Photosynthesis

  3. Respiration

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

Absorption is the process by which plants take in water and nutrients from the soil through their roots.