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 economics environmental economics acid rain air pollution - effects and control air pollution and its effects

How does acid precipitation(acid rain) affect plants?

  1. It releases H$+$ ions, thereby increasing the of rate photophosphorylation in green cells

  2. It precipitates organic acids in palisades cells of leaves, thereby inhibiting respiration

  3. It injuries foliage leading to reduction in photosynthesis, biomass and occasionally death

  4. It precipitates toxic nutrients in soil leading to growth inhibition in trees
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Acid precipitation lowers soil and water pH and directly damages plant foliage, leading to reduced photosynthetic capacity, lower biomass accumulation, and occasionally plant death.

Multiple choice botany ecological adaptations, succession and ecological services plant adaptation adaptation in plants plant habitat importance and classification of angiosperms

Which of the following is not an adaptive feature of plants growing in physiologically dry soil?

  1. Pneumatophore

  2. Vivivary

  3. Sunken stomata

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

Physiologically dry soil means that water is present in soil but due to high levels of salt, it is not available to plants as plants cannot easily absorb the water present in soil. Such plants are called halophiles, e.g., mangrove plants like Sonnertia, Rhizophora, Avicennia etc. Such plants show several unique features such as presence of pneumatophores and vivipary. Sunken stomata is not shown by mangroves but is shown by xerophytes which grow in physically dry soil. Thus, the correct answer is option C.

Multiple choice botany male & female gametophytes: structure and development pollen grain androecium male gametophyte

Which one is resistant to enzyme action?

  1. Pollen exine

  2. Leaf cuticle

  3. Cork

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

The pollen exine of the pollen grains consists most resistant biological material known as Sporopollenin. It is resistant to both microbial and chemical decomposition by which it preserves pollen grains during fossilization.

So the correct option is 'Pollen exine'.

Multiple choice geography hydrologic cycle the atmosphere elements of weather and climate :humidity hydrologic cycle and its components elements of weather and climate : temperature

Plants lose water to the air through _____.

  1. Transpiration

  2. Respiration

  3. Photosynthesis

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

Transpiration is the loss of water from a plant in the form of water vapor. Water is absorbed by roots from the soil and transported as a liquid to the leaves via xylem. In the leaves, small pores allow water to escape as a vapor.

Multiple choice evs whose forests? improved methods of agriculture cropping patterns food for all conservation of forest and wildlife wildlife deforestation and conservation

Xanthium, Parthenium, Cyperus rotundus are the examples of 

  1. Diseases

  2. Pesticides

  3. Weeds

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

Weeds are unwanted plants which grow along with the crop plants in the cultivated field. Some common weeds in India are Amaranthus (Chaulai), Parthenium (Gajar ghas), Cyperus rotundus (Motha), Chenopodium (Bathua), Xanthium (Gokhroo). Weeds compete with the crop plants for nutrients, space, light and water. This results in lowering the food grain quality and reduction in crop yield. Weeds may produce toxic substances which may interfere with crop growth. During harvesting, weeds get mixed up with crops to lower down its quality.

So, the correct answer is 'Weeds'.

Multiple choice biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

All the following involves osmosis except.

  1. Water from soil entering a root hair

  2. Water passing from root hair to adjacent cells

  3. Water passing up a xylem vessel element to xylem vessel element above it

  4. Water entering a mesophyll cell from xylem vessel element
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Osmosis is the movement of water across a semi-permeable membrane. Water moving up a xylem vessel is primarily driven by transpiration pull and cohesion-tension, not osmosis.

Multiple choice biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

When a plant cell is placed in a solution which is hypotonic to the cell sap, which of the following conditions will not apply

  1. The water potential of the cell sap will rise

  2. The suction pressure of the cell sap will fail

  3. The cell will become turgid

  4. The wall pressure of the cell will fail
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

If a cell is placed in hypotonic solution, water start moving into the cell by the process of endosmosis and cell become turgid.

Multiple choice biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

All the following involve osmosis except.

  1. Movement of water from soil to root

  2. Movement of water from root hair to endodermis and pericycle

  3. Movement of water between xylem elements

  4. Movement of water form xylem to mesophyll cell of leaves
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Similar to the previous question, movement of water between xylem elements is bulk flow, not osmosis.

Multiple choice biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

Consider the following events involved in stomatal opening:
1. Turgor pressure of guard cells increases
2. $K^+$ ions move into guard cells
3. pH of guard cells decreases
4. Water moves into guard cells
What is the correct sequence of these events leading to stomatal opening:

  1. 2-4-3-1

  2. 3-2-4-1

  3. 2-3-4-1

  4. 3-1-2-4
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The sequence is: K+ ions move into guard cells (2), which lowers the water potential, causing water to move in (4), which increases the turgor pressure (1). The pH change (3) is associated with the K+ transport.

Multiple choice biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

The movement of a molecule across a typical plant cell about 50mm takes aproximately

  1. 2.5m

  2. 2.5 h

  3. 2.5s

  4. none of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Lines of stomates (shown by the orange colour of the guard cells) lie along the flanks describe the status and movement of water in plants, soil and the atmosphere. This internal hydrostatic pressure (also called turgor pressure) is typically 0.5 away from the cell wall, and solution with small molecular weight solutes. 

So, the correct option is "D" (None of these).

Multiple choice biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

What happens when wilted vegetable are dipped in water _________________.

  1. They regain their size

  2. Remain to be same

  3. Colour will change

  4. Decrease in size because of lose of water.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

  • After dipping into water wilted vegetable regain their size, as water travells through a network of veins through out the plant and cell are hydrated and refirm their size. by a process called osmosis .
  • Leaves turn yellow or red when they falls , in fallpalnt breakdown and reabsorb chlorophyll, letting the colours of other pigments show through , hence colour changes.
  • When vegitables are wilted due to  dehydration, their size decreases due to loss of water.
 So the correct answer is " They regain their size".

Multiple choice biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

Active absorption is affected by:

  1. Osmotic concentration

  2. Associate tissue structures

  3. Transpiration

  4. Sucking capacity of root hair
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Active absorption refers to absorption against the concentration gradient. Absorption of a solute from a region of low concentration to a region of higher concentration by the help of energy, is called active absorption. Hence, active absorption depends on osmotic concentration.

Multiple choice biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

Minerals are absorbed by the plants, through

  1. Pressure flow

  2. Diffusion

  3. Active transport

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

Minerals are absorbed by plants through active transport as minerals are present in the soil mostly in the form of charged particles which fail to move across cell membrane and concentration of minerals in the cell is usually greater than that present in the soil solution. Therefore, most of the minerals are absorbed by active mechanism involving expenditure of energy in the form of ATP.

Hence, C is the correct answer.

Multiple choice biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

The energy is required in absorption of water by

  1. Active absorption

  2. Passive absorption

  3. Both passive and active absorption

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

Absorption of water takes place by both active and passive absorption.
Water, as per some theory, is absorbed against the concentration gradient. This type of absorption is termed active absorption where the movement is against the concentration gradient and requires energy in the form of ATP.

Most of the plants observe passive absorption, meaning, the movement is without utilization of metabolic energy. 
Thus, the correct answer is option (C).