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 biology constitutes of diet nutrients and foodstuffs simple test for nutrients test for nutrients

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 part of the leaf exposed to light

  2. Starch will be found in the entire leaf

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

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

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 starch will be found only in the part of the leaf exposed to light. This is because starch is the end product of photosynthesis. The process of photosynthesis will take place only in the location of leaves where light is present. 

In the given question, the leaf is partially covered which means, no photosynthesis takes place in these areas. Thus, when iodine is introduced to these parts after boiling, it cannot give blue-black color. Whereas the other parts which were exposed to sunlight will give blue-black color.
So, the correct answer is option A.

Multiple choice chemistry water and air and their importance natural cycles and resources constituents of air component of air - nitrogen

Plants consumes ____________ and gives _____________.

  1. oxygen, carbon dioxide

  2. carbon dioxide, oxygen

  3. sulphur dioxide, oxygen

  4. oxygen, sulphur dioxide
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Plants consumes carbon dioxide and gives oxygen.

As in the process of photosynthesis plants consumes carbon dioxide and during photosynthesis plants release oxygen.

Multiple choice chemistry water and air and their importance natural cycles and resources constituents of air component of air - nitrogen

All the plants require nitrogen for:

  1. reproduction

  2. photosynthesis

  3. transpiration

  4. growth
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
All the plants require nitrogen for growth. Nitrogen is found in healthy soils and give plants the energy to grow and produce fruit or vegetables. Nitrogen is part of the chlorophyll molecule, which gives plant their green colour and is involved in  creating food for the plant through photosynthesis.
So, the correct answer is 'growth'
Multiple choice biology plant growth seed dormancy fruit plants: structure and function

A method of breaking dormancy and allowing ample absorption of water is

  1. Stratification

  2. Scarification

  3. Vernalisation

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

A. Stratification: Seeds are moistened and exposed to oxygen for variable period at low or high temperature.

B. Scarification: Hard, impermeable seed coat is weakened or ruptured by filing, chip­ping, abosrbing hot water.

C. Vernalisation- The cooling of seed during germination in order to accelerate flowering when it is planted.

D. Devernalisation- The heating of seed during germination in order to deaccelrating flowering when it is planted.
So, the correct answer is 'Scarification'.

Multiple choice biology mineral nutrition in plants hydroponics nutrients and nutrition hydroculture

When we boil tulsi leaves in water, water acquires a characteristic smell of leaves because

  1. Smell of leaves diffuse in water

  2. Leaves melt in water

  3. Stored wastes in the leaves dissolve in water

  4. Leaves pollute water
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Water acquires a characteristic smell because the smell of leaves diffuse in water, tulsi leaves never melt in water or pollute water.

So, the correct option is 'Smell of leaves diffuse in water'.

Multiple choice apical dominance auxins and gibberellins growth and development plant growth and development biology

A potted plant placed near the window bends outwardly due to 

  1. Greater oxygen availability to the tip.

  2. More auxin content on the shaded side.

  3. Greater light availability to tip.

  4. Availability of necessary warmth to the tip.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Greater growth on the shaded side of the stem is due to more accumulation of auxin on the shaded  side than on the illuminates. Auxin causes bending of plant towards light. Phototropism is induced by auxin hormone.

Multiple choice apical dominance auxins and gibberellins growth and development plant growth and development biology

In tea plantations and hedge making, gardeners trim the plants regularly so that they remain bushy. Scientific explanation behind this is

  1. Removal of apical dominance

  2. Growth of lateral buds

  3. Suppression of lateral buds

  4. Both (a) and (b)
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Auxin is a hormone present in plants at the tip of the stem. Its function is to maintain apical dominance (where main stem of the plant is dominant over other side branches) and to inhibit growth of lateral buds. That's why gardeners trim the plants regularly so that the plant grows laterally and remains bushy after removal of auxin.

Thus, the correct answer is 'Both (a) and (b).'

Multiple choice biology transport in plant transport of water and minerals conduction of water and minerals absorption of water and minerals in plants

The structures present in the roots to absorb water and minerals are 

  1. Epidermal appendages

  2. Epidermal extensions

  3. Hypodermis

  4. Endodermis
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • Root hairs are the lateral epidermal extensions or tubular outgrowths in the roots (zone of maturation) of plants.
  • The root hairs penetrate into the soil and prevent harmful microbes from entering the plant through the xylem vessels.
  • They increase the surface area for absorption of water and nutrients from the soil.
  • So, the correct answer is 'Epidermal extensions'.
Multiple choice biology transport in plant transport of water and minerals conduction of water and minerals absorption of water and minerals in plants

Select the correct sequence of passive absorption path of water in a plant

  1. Soil $\rightarrow $ Root hair $\rightarrow $ Epidermis $\rightarrow $ Secondary cortex $\rightarrow $ Endodermis $\rightarrow $ Pericycle $\rightarrow $ Metaxylem
  2. Soil $\rightarrow $ Root hair $\rightarrow $ Cortex $\rightarrow $ Passage cells $\rightarrow $ Pericycle $\rightarrow $ Root protoxylem $\rightarrow $ Root Metaxylem
  3. Soil $\rightarrow $ Epidermis $\rightarrow $ Cortex $\rightarrow $ Endodermis $\rightarrow $ Pericycle $\rightarrow $ Root metaxylem $\rightarrow $ Root protoxylem $\rightarrow $ Root hair
  4. Soil $\rightarrow $ Epidermis $\rightarrow $ Cortex $\rightarrow $ Pericycle $\rightarrow $ Endodermis $\rightarrow $ Root protoxylem
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Option (A)
Soil $\rightarrow$ Root hair $\rightarrow$ Epidermis $\rightarrow$ Secondary cortex $\rightarrow$ Endodermis $\rightarrow$ Pericycle $\rightarrow$ Metaxylem.
The absorption of water by plants is essential for various metabolic activities. Soil water enters into the cortical cells through root hairs to reach the xylem of roots to maitain the supply of water.
Multiple choice biology transport in plant transport of water and minerals conduction of water and minerals absorption of water and minerals in plants

At low temperature water absorption decreases due to
(I) An increase in the viscosity of water and protoplasm. 
(II) A decrease in the permeability of cell membranes.
(III) A decrease in the metabolic activities of root cells. 
(IV) A check in the growth and elongation of roots.

  1. I and II are correct

  2. I and III are correct

  3. I, II and III are correct

  4. All are correct
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

At low temperature, there will be physical changes in water and also water absorption, both due to active and passive means will decrease. There will be an increase in viscosity of water and decrease in respiration in roots. The decreased respiration will lead to reduced supply of ATP. Hence, active absorption will decrease. Also, growth of roots will suffer due to decrease in rate of metabolism. The cell membrane will become less permeable and there will be lesser movement of solutes across them. As temperature rises, the lipids become more fluidic and permit movement of more solutes across the membrane.

Multiple choice biology transport in plant transport of water and minerals conduction of water and minerals absorption of water and minerals in plants

Root cap plays no role in the absorption of water in a plant, because

  1. Its cells are loosely arranged.

  2. It has no root hairs.

  3. It has no connection with xylem tissue.

  4. Its cells are dead.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Root hairs are unicellular extensions of root epidermis or epiblema. They increase the surface area for absorption and are involved with absorption of water. Root cap typically lacks root hairs and hence not involved in absorption process.

Multiple choice biology transport in plant transport of water and minerals conduction of water and minerals absorption of water and minerals in plants

Maximum absorption of water by a root occur in the region of

  1. Cell division

  2. Cell elongation

  3. Cell maturation

  4. Cell division and root cap together
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In a typical dicot root; root hairs are present in the zone of cell maturation. Root hairs are unicellular extensions of root epidermis, called as epiblema, which absorb water due to increased surface area for absorption. Zone of cell division, zone of elongation and root cap generally lack root hairs.