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 identifying the plants absorption of water from the soil root system the root system

Velamen found in epiphytic roots is meant for

  1. Absorption of water from host

  2. Absorption of water from air

  3. Perennation

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

Velamen is a spongy, multiple epidermis that covers the roots of some epiphytic or semi-epiphytic plants, such as orchid and Clivia species. The velamen of an orchid is the white or gray covering of aerial roots. When dry and usually more green when wet as a result of the appearance of underlying photosynthetic structures. It is many cell layers thick and capable of absorbing atmospheric moisture and nutrients. Often, the roots of orchids are associated with symbiotic fungi or bacteria, the latter may fix nutrients from the air. So, velamen is meant for absorption of water from air and not for absorption of water from host, perennation or protection.

Thus, the correct answer is option B.

Multiple choice evs identifying the plants absorption of water from the soil root system the root system

The roots are important parts of the plant because

  1. The roots provide anchorage

  2. The roots help in making food

  3. The roots absorb water

  4. Both A and C
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Functions of root:-

  • It helps in the absorption of water and mineral.
  • Holds the soil hence provide anchorage.
  • Modify to store food.
  • In hydrophytes helps to take oxygen called pneumatophores.
  • Provide support to the plant body.
So the correct option is "Both A and C".

Multiple choice evs identifying the plants absorption of water from the soil root system the root system

A plant with epidermis specialised to absorb mositure from air is?

  1. Avicennia

  2. Vanda

  3. Rhizophora

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

A plant with epidermis specialized to absorb moisture from the air is Vanda because vanda is an epiphyte with modified epidermis called velamen. As it stays on the host plant branches, its roots hang in the air absorbing moisture from the atmosphere.

So, the correct option is 'Vanda'.

Multiple choice evs identifying the plants absorption of water from the soil root system the root system

Which of the following pairs is/are correct?
(A) Main root - Storage
(B) Lateral root - Absorption
(C) Root hair - Conduction

  1. All are correct

  2. A and B

  3. Only A

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

The region of cell differentiation or maturation is differentiated into root hairs. Most of the water absorption occurs through this region.

The roots are modified to form storage roots such as conical, fusiform, napiform, tuberous
Lateral roots extend horizontally from the primary root and this contributes to water uptake and nutrient uptake.

So, the correct option is 'A and B'


Multiple choice biology human system gas exchange and smoking gas exchange gas exchange in humans

Plants and animals help in maintaining the balance of

  1. Trees and animals

  2. Oxygen and carbon dioxide

  3. Green plants and plant eaters

  4. Water and minerals
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

  • All plants and animals on earth engage in a process called respiration.
  • Respiration combines oxygen and the food created during photosynthesis to produce usable energy. 
  • One of the byproducts of respiration is CO2,  if plants stop to take up CO2 and stop releasing O2, then plants will stop to convert sunlight into carbohydrates, and die.
  • The death of autotrophs would lead to a chain reaction to the death of all higher-order organisms, Hence, Plants and animals help in maintaining the balance of Oxygen and carbon dioxide. 
So, the correct answer is 'Oxygen and carbon dioxide'.

Multiple choice biology movement and locomotion in living organisms movements in plants coordination in plants tropic and nastic movements in plants

Example of positive geotropism is 

  1. Closing of flowers

  2. Upwards growth of stem

  3. Downward growth of root

  4. Lateral growth of root
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Positive geotropism is the movement towards earth. In the case of roots, they grow towards the earth and are thus, called as positively geotropic. Whereas shoots are negatively geotropic.

Multiple choice biology movement and locomotion in living organisms movements in plants coordination in plants tropic and nastic movements in plants

Irritability/Reactivity/Sensitivity of a plant is

  1. Response to stimulus in soil

  2. Response to a change in environment

  3. Movement caused by an external force

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

Irritability, reactivity and sensitivity are excitatory response shown by plants to respond to changes in their environment. The most common response shown by plants is movement in response to environment change. For example, closing of leaves of Mimosa pudica on touching or closing of traps on a Venus fly trap.

Thus, the correct answer is option B. 

Multiple choice biology movement and locomotion in living organisms movements in plants coordination in plants tropic and nastic movements in plants

The movement of plant organs in response to force of gravity is called

  1. Phototropism

  2. Thigmotropism

  3. Geotropism

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

The movement of plant part in response to contact with a solid touch is called as thigmotropism. The movement of plant part in response to light is called as phototropism. The movement of plant part in response to force of gravity is called as geotropism. The movement of plant part in response to external chemical stimulus is called as chemotropism.

Thus, the correct answer is option C.

Multiple choice biology movement and locomotion in living organisms movements in plants coordination in plants tropic and nastic movements in plants

The stem bends upwardly and root downwardly under the influence of gravity because

  1. Of nature of stem and root

  2. Stem is photonastic and root geonastic

  3. Stem is negatively geotropic and root positively geotropic

  4. Stem is negatively hydrotropic and root positively hydrotropic
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The movement of plant part in response to force of gravity is called as geotropism. The movement of plant part towards the gravity is called as positive geotropism. Roots show positive geotropic movement. The movement of plant part away from the gravity is called as negative geotropism. Stems show negative geotropic movement. 

Thus, the correct answer is option C.

Multiple choice biology movement and locomotion in living organisms movements in plants coordination in plants tropic and nastic movements in plants

Phototropism of stem and geotropism of root are due to

  1. Epinasty and hyponasty

  2. Effect of light

  3. Differential hormonal effect

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

Phototropism of shoot and geotropism of root are due to several hormonal action. The hormones responsible include auxin plant hormone. Auxin is responsible for the growth of shoot positively phototrophic. Auxin also induces apical dominance in shoots.

Multiple choice biology movement and locomotion in living organisms movements in plants coordination in plants tropic and nastic movements in plants

Growth of plant in response to external factors is called 

  1. Tropic movement

  2. Movement

  3. Secondary growth

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

A tropism is a biological phenomenon, indicating growth or turning movement of a biological organism, usually a plant, in response to an environmental stimulus. Tropisms are typically associated with plants (although not necessarily restricted to them). Where an organism is capable of directed physical movement (motility), movement or activity in response to a specific stimulus is more likely to be regarded by behaviorists as a taxis (directional response) or a kinesis (non-directional response).
Therefore, the correct answer is option A.

Multiple choice biology movement and locomotion in living organisms movements in plants coordination in plants tropic and nastic movements in plants

The movement of a plant in response to the concentration of water is known as hydrotropism.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The movement of plant in response to water is known as hydrotropism. The movement or direction of growth depends upon the concentration or gradient of water. Auxin plays an important role in bending of roots towards water. It causes on side of roots to grow faster and the other side is grows slowly. This leads to bending of roots towards water.
So, the given statement is true.
Multiple choice biology movement and locomotion in living organisms movements in plants coordination in plants tropic and nastic movements in plants

The movement of plant organs in response to the force of gravity is called as

  1. Hydrotropism

  2. Geotropism

  3. Heliotropism

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

Gravitropism (also known as geotropism) is a turning or growth movement by a plant or fungus in response to gravity. It is a general feature of all higher and many lower plants as well as other organisms.Therefore, the correct answer is option B.