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 evs food components simple test for nutrients test for nutrients protein and its function energy from different food components nutrients and foodstuffs

A green leaf is partially covered and placed in the light for several days. If it is then boiled and tested for starch with iodine, what will be the result?

  1. Starch will be found only in the shaded part of the leaf

  2. Starch will be found in the entire leaf

  3. Starch will be found only in the part of the leaf exposed to light

  4. Starch not be found in the leaf at all
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The leaf on the right shows a positive test for starch in the areas which contained chlorophyll, and a negative test for starch in the areas which lack chlorophyll. This is evidence that chlorophyll is required for photosynthesis. A plant can be 'de-starched' by leaving it in the dark for a few hours. So, the correct option is "C" (Starch will be found only in the part of the leaf exposed to light).

Multiple choice botany plant physiology mechanism of absorption mineral absorption significance of transpiration transport of food, water and minerals mineral transport

Choose the correct answer from the alternatives given.
Minerals enter a plant mainly by:

  1. diffusion

  2. pressure flow

  3. translocation

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

Active transport is a process that is required to move molecules against a concentration gradient. For plants to take up mineral ions, ions are moved into root hairs, where they are in a higher concentration than in the dilute solutions in the soil. So, the correct answer is "Active Transport".

Multiple choice biology adaptation terrestrial adaptations in plants adaptation in terrestrial plants terrestrial adaptation desert ecosystem terrestrial adaptation in animals

Stems are covered by waxy coating in order to prevent

  1. Loss of water

  2. Photosynthesis

  3. Loss of carbon dioxide

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

Stems are covered by waxy coating in order to prevent the loss of water and helps in maintaining the water level in the plant under dry conditions.

Multiple choice biology adaptation terrestrial adaptations in plants adaptation in terrestrial plants terrestrial adaptation desert ecosystem terrestrial adaptation in animals

Stems are modified in cactus in order to perform

  1. Photosynthesis

  2. Digestion

  3. Excretion

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

Stems are modified in cactus in order to perform Photosynthesis. Stems are flattened and green having thick waxy coating over them and helps in performing photosynthesis as leaves are converted into spines.

Multiple choice biology caskets of life observation of cells observing cells cell as structural and functional unit

Peel should not be allowed to dry while observing under microscope beacuse

  1. It causes more stomata to open

  2. It causes closure of stomata

  3. It results in increase in total number of stomata

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

The observation of the onion peel is to see the arrangement of the cells that are separated by the thin layer. In onion, the peel is taken out from the scaly leaves that do not perform photosynthesis. They perform the function of storage. So, they do not show the stomata or the chloroplast. After the removal, the peel is kept in water to avoid drying of the leaves.

Hence, the correct answer is 'None of the above'

Multiple choice biology caskets of life observation of cells observing cells cell as structural and functional unit

Given below are the steps in the preparation of a temporary mount of a stained leaf peel.
(i) Cover the material with the cover slip
(ii) Transfer the stained peel to a clean glass slide and add a drop of glycerine
(iii) Remove the peel from lower surface of leaf
(iv) Drop it in water in Petri dish and add a drop of  safranin stain.
The correct sequence of the experiment steps is

  1. (a) (iii), (iv), (ii), (i)

  2. (b) (i), (ii), (iii), (iv)

  3. (c) (ii), (iii), (iv), (i)

  4. (d) (iii), (iv), (i), (ii)
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

To prepare a leaf peel mount: first remove the peel (iii), place it in water/stain (iv), transfer to a slide with glycerine (ii), and finally apply the cover slip (i).

Multiple choice botany mineral nutrition in plants deficiency diseases and symptoms deficiency symptoms macronutrients and micronutrients

Which one of the following statements can best explain the term critical concentration of an essential element? 

  1. Essential element concentration below which plant growth is retarded

  2. Essential element concentration below which plant growth becomes enhanced

  3. Essential element concentration below which plant remains in the vegetative phase

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Critical Concentration is the term which is used to define the concentration of essential elements below which the growth of plant is Retarded or Reduced. Also, if the concentration of essential elements rise above the critical concentrations.  it leads to Toxicity. So, the correct answer is "Essential elements concentration below which plant growth is retarded."
Multiple choice biology cell structure animal cell plant and animal cell cell structure and micro-organisms

When waters enters the cell, one of the pressure is exerted on the cell wall  

  1. Osmotic pressure

  2. Suction pressure

  3. Turgor pressure

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

When water enters the cell of a plant cytoplasm and exerts an outward pressure and that pressure is called turgor pressure. A cell wall is rigid and flexible therefore exerts an equal and opposite wall pressure against the expanding protoplasm. Thus, turgor pressure becomes equal to the wall pressure when no exchange of water takes place and equilibrium are established.

Multiple choice biology plants in daily life uses of gymnosperms introduction to gymnosperms importance of plants

The leaves of gymnosperms are well-adapted to withstand extremes of temperature, humidity and wind, because of which of the following features?

  1. Needle like leaves

  2. Thick cuticle

  3. Sunken stomata

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

Conifers have a number of xerophytic characters such as needle-like (e.g., Pinus), scale-like {e.g., Thuja) or small and leathery leaves {e.g., Araucarias), thick cuticle, sclerenchymatous hypodermis and sunken stomata to reduce transpiration. They are, thus, well adapted to tide over the winter period when the soil becomes frozen and availability of water is very little.

So the correct option is D.

Multiple choice botany the leaf mechanism of absorption mineral absorption significance of transpiration

Significance of transpiration lies in

  1. Circulation of water

  2. Absorption and distribution of water

  3. Regulating the temperature of the plant body

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

Transpiration generates tension in plants. This tension is the main pulling force which pulls water to great heights in vascular plants. Thus, transpiration leads to the ascent of sap. Without transpiration water and minerals will not rise from roots to aerial parts of plants and trees. Transpiration also causes surface cooling of leaves and hence regulates the temperature of the plant body. At the same time, it is essentially a wasteful process. As much as 99 percent of water absorbed by a plant goes waste into the atmosphere. Thus, transpiration has been called as a necessary evil.

Multiple choice botany the leaf mechanism of absorption mineral absorption significance of transpiration

Exchange of gases occur through 

  1. Stomata

  2. Lenticels

  3. Root surface

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

In plants, gas exchange occurs through small pores in the leaf surface called stomata. Stomata can open to allow the exchange of gasses and close to reduce water loss from the plant. In the covering of the secondary structure of the stem of woody plants gas exchange is made through the lenticels of the periderm (small breaches of the cork). The cork of mature roots is also perforated by non-suberized pores called lenticels. These enable oxygen to reach the intercellular spaces of the interior tissues and carbon dioxide to be released into the atmosphere.

Multiple choice botany the leaf mechanism of absorption mineral absorption significance of transpiration

Which of the following processes lower the temperature of leaves cooling effect?

  1. Respiration

  2. Photosynthesis

  3. Transpiration

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

Transpiration is essentially similar to evaporation of water. It is the loss of water in vapour form through stomata. Water molecules tend to remain in the liquid state rather than moving to vapour state; so during evaporation water molecules absorb a lot of heat energy, this generates a cooling effect.