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 ecological adaptations, succession and ecological services extreme adaptations adapting to a habit adaptive features aquatic plant adaptations pollination through water

In xerophytes, the osmotic concentration of cell sap is

  1. Less than normal

  2. Normal

  3. More than normal

  4. No osmotic pressure at all
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The osmotic concentration of cell sap is higher in xerophytes to allow them to absorb water in an otherwise water deficient environment. The higher osmotic concentration would mean a lower water potential. A lower water potential will be advantageous to xerophytes as water always flows from a higher water potential to lower water potential.

Multiple choice botany ecological adaptations, succession and ecological services extreme adaptations adapting to a habit adaptive features aquatic plant adaptations pollination through water

Plants give out water through the pores present under their leaves. The plants living in deserts need to reduce the loss of water because water is very scarce in deserts. Which of the following is an adaptation developed by the desert plants to manage the above situation?

  1. They have lots of branches and leaves.

  2. They do not shed leaves in the summer.

  3. They develop roots which come above the ground.

  4. Their leaves are modified into spines.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Most species of desert plants have lost true leaves, retaining only spines, which are highly modified leaves. As well as defending against herbivores, spines help prevent water loss by reducing air flow close to the cactus and providing some shade. In the absence of leaves, enlarged stems carry out photosynthesis.

So, the correct answer is 'Their leaves are modified into spines'.

Multiple choice botany ecological adaptations, succession and ecological services extreme adaptations adapting to a habit adaptive features aquatic plant adaptations pollination through water

Phreatophytes are xerophytes with roots

  1. Spread along the soil surface

  2. Well spread in the soil

  3. Very deep reaching ground water fringe

  4. Very deep but well above ground water
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A phreatophyte is a deep-rooted plant that obtains a significant portion of the water that it needs from the phreatic zone (zone of saturation) or the capillary fringe above the phreatic zone. Phreatophytes are plants that are supplied with surface water and often have their roots constantly in touch with moisture. These plants have very deep roots that are able to reach the water table. So the correct answer is ' Very deep reaching ground water fringe'. 

Multiple choice botany ecological adaptations, succession and ecological services extreme adaptations adapting to a habit adaptive features aquatic plant adaptations pollination through water

Drought endurers are

  1. Succulent xerophytes

  2. Perennial xerophytes

  3. Annual xerophytes

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

Drought endurers are plants that can survive drought periods by maintaining their physiological functions, typically through deep root systems or water storage, and are usually perennial. Annuals are typically drought escapers.

Multiple choice botany ecological adaptations, succession and ecological services extreme adaptations adapting to a habit adaptive features aquatic plant adaptations pollination through water

In xerophytic leaf, the stomata are situated 

  1. On both surface

  2. On upper surface

  3. On lower surface

  4. Absend from both surfaces
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The xerophytic plants are the plants present in the desert and other dry environments. The rate of transpiration is high in xerophytic plants due to high temperatures. In order to minimize the rate of transpiration, they have sunken stomata.

Thus, the correct answer is option (C),

Multiple choice botany ecological adaptations, succession and ecological services extreme adaptations adapting to a habit adaptive features aquatic plant adaptations pollination through water

Sunken stomata occur in

  1. Xerophytes

  2. Hydrophytes

  3. Mesophytes

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

Sunken stomata are a specific adaptation in xerophytes to create a micro-environment of higher humidity around the pore, thereby reducing the rate of transpiration.

Multiple choice botany ecological adaptations, succession and ecological services extreme adaptations adapting to a habit adaptive features aquatic plant adaptations pollination through water

An adaptation of plants to water scarcity and high temperature is

  1. Succulent stem stores water

  2. Poorly developed root

  3. They shed their leaves

  4. In unfavourable season, plants survive in dormant state as seeds
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • Water storage in stem and tubers is an adaptation of plants to thrive in harsh environments with high temperatures and scarce water. Such plants called xerophytes usually develop succulent stems that can store water.
  • They have a very extensive root system to absorb the maximum amount of water from the soil.
  • Other adaptations include thick waxy cuticle, reduced leaf size, densely packed leaves, reduced number of stomata in pitted and grooved positions.
Multiple choice botany ecological adaptations, succession and ecological services extreme adaptations adapting to a habit adaptive features aquatic plant adaptations pollination through water

Opuntia has spine like leaves which help in 

  1. Reducing the rate of transpiration

  2. Increasing the rate of transpiration

  3. Increasing the rate of photosynthesis

  4. Reducing the rate of photosynthesis
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Opuntia has spine which are highly modified leaves. Spines help prevent water loss by reducing the rate of transpiration.
So, the correct option is 'Reducing the rate of transpiration'
Multiple choice botany ecological adaptations, succession and ecological services extreme adaptations adapting to a habit adaptive features aquatic plant adaptations pollination through water

'Pebble plant' have _____________.

  1. Leaves modified to spines

  2. Leaves are absent

  3. Leaves are swollen

  4. Leaves modified to reduce transpiration
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Lithops (stone-faced as the plants appear stone-like)  is a genus of succulent plants in the ice plant family, Aizoaceae. They avoid being eaten by blending in with surrounding rocks and are often known as pebble plants or living stones. These are small succulent plants that survive in their harsh environment by having much of the plant body below ground. Each individual plant consists of two succulent leaves fused together in the shape of an inverted cone (although some species will produce multi-headed plants). The fissure at the top of the plant is the division between the two leaves and is spine-like. 

So, the correct answer is 'leaves modified to spines'.

Multiple choice botany ecological adaptations, succession and ecological services extreme adaptations adapting to a habit adaptive features aquatic plant adaptations pollination through water

The most common organic solute stored by xerophytes for maintaining osmotic and water potential is

  1. Glucose

  2. Sucrose

  3. Raffinose

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

Proline is a common compatible solute (osmolyte) accumulated by plants, especially xerophytes and halophytes, to maintain osmotic balance and protect cellular structures under drought stress.

Multiple choice biology adapting to a habit extreme adaptations adaptive features adaptations of organisms

The leaves of desert plants are not torn away by high wind velocity because of

  1. Spines

  2. Bending towards opposite side

  3. Sclerenchymatous tissue that provides extra mechanical support

  4. Tearing of corners while the middle remains saved
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Desert plants often develop sclerenchymatous tissues, which are rigid, dead cells that provide significant mechanical strength and structural support. This reinforcement helps the leaves withstand high wind velocities without tearing.

Multiple choice biology adapting to a habit extreme adaptations adaptive features adaptations of organisms

Sun plants have

  1. More mechanical tissues

  2. Extensive root system

  3. Abundant flowering

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

Sun plants (heliophytes) are adapted to high-light environments and typically possess more mechanical tissue for structural integrity, extensive root systems to support high transpiration rates, and often show more vigorous growth and flowering compared to shade plants.

Multiple choice biology adapting to a habit extreme adaptations adaptive features adaptations of organisms

' Pebble plant ' have 

  1. Leave modified to spines

  2. Leaves are absent

  3. Leaves are swollen

  4. Leaves modified to reduce transpiration
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Lithops plants or Pebble plant consist of one or more pairs of bulbous, almost fused leaves opposite to each other and hardly any stem. The slit between the leaves contains the meristem and produces flowers and new leaves. The leaves of Lithops are mostly buried below the surface of the soil, with a partially or completely translucent top surface known as a leaf window which allows light to enter the interior of the leaves for photosynthesis. 

So the above selected option is correct