Tag: extreme adaptations

Questions Related to extreme adaptations

Petioles are inflated in floating hydrophytes 

evs life in water aquatic plant adaptations pollination through water aquatic adaptation extreme adaptations

  1. Wolffia

  2. Eichhornia

  3. Salvinia

  4. Ceratophyllum

Show answer
Correct Option: B
Explanation:

The petiole is the stalk that attaches the leaf blade to the stem. Water hyacinth leaves in natural populations vary from being long and thin‐petioled to being short with inflated petioles. water hyacinth is a floating hydrophyte that has an inflated petiole which helps in keeping it on top of the water level thus allowing it not to sink. So the correct answer is ' Eichhornia or water hyacinth. '

A rooted floating leaved hydrophyte is

evs life in water aquatic plant adaptations pollination through water aquatic adaptation extreme adaptations

  1. Nymphaea

  2. Hydrilla

  3. Ceratophyllum

  4. Eichhornia

Show answer
Correct Option: A
Explanation:
Rooted Hydrophytes with Floating Leaves:
The roots of these type of hydrophytes are fixed in mud, but leaves have long
petioles which keep them floating on the water surface. Except leaves, the restof the plant body remains in water. Some examples are Nelumbo nucifera,
Nymphaea stellate (water lily), Trapa, Marsilea. 
So the correct answer is 'Nymphaea'. 

Plants growing in dry habitat are 

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

  1. Lithophytes

  2. Mesophytes

  3. Hydrophytes

  4. Xerophytes

Show answer
Correct Option: D

Which combination of the statements is incorrect for the adaptation in cactus?

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

  1. The cactus plants store water in their stems which carries out photosynthesis and is covered by the cuticle.

  2. Spines are the modified leaves of the cactus plant. Which reduce the loss of water through transpiration.

  3. The cactus plants have very short roots which cannot properly absorb water from the soil.

  4. The cactus plants lose a huge amount of water through transpiration so they cannot survive in deserts for a long time.

Show answer
Correct Option: C,D
Explanation:

The succulent stem of the cactus plants usually store water and carry out photosynthesis also. The cactus stem contains a tough and waxy outer layer, called cuticle. The cactus plants possess modified leaves shaped like thin spines or thorns that decrease water loss through transpiration. 

The cactus plants contain long roots that efficiently absorb water from the ground. Due to the low transpiration rate, the cactus plants can remain alive in deserts for a longer period of time. 
So, the options C, The cactus plants have very short roots which cannot properly absorb water from the soil and D, The cactus plants lose a huge amount of water through transpiration so they cannot survive in deserts for a long time are incorrect for the adaptation in cactus. 
 

Stomata open at night and close during day in

botany ecological adaptations, succession and ecological services extreme adaptations adapting to a habit adaptive features

  1. Xerophytes

  2. Gametophytes

  3. Mesophytes

  4. Hydrophytes

Show answer
Correct Option: A
Explanation:

Stomata in xerophytes open in night and remain close during day to prevent loss of water through transpiration.

"Patther phul" is _______________.

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

  1. Lichen

  2. Xerophytic plant

  3. Living stones

  4. Hydrophytic plant

Show answer
Correct Option: B
Explanation:

"Patther phul" or stone flower or rock moss is a xerophytic plant or xerophytic shrub occurring wild on rocky ground( not much water present) As it is a plant which needs very little water it is called a xerophyte and occurs in the region of Gujarat 

So, the correct answer is 'Xerophytic plant'.

Choose the desert plant from the following:

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

  1. Lotus

  2. Banyan tree

  3. Opuntia

  4. Neem tree

Show answer
Correct Option: C
Explanation:

One of the most commonly found plants in deserts is opuntia. it is a type of cactus. It is also called prickly pear. It is used to treat burns, diabetes, ulcers, inflammation, etc.

So, option c is the correct answer.

Xerophytes have very small leaves or spines to.

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

  1. Reduce weight

  2. Reduce loss of water

  3. Reduce volume

  4. Be beautiful

Show answer
Correct Option: B
Explanation:

Xerophytes have very small leaves or spines to reduce loss of water.

A xerophyte is a species of plant that has adapted to survive in an environment with little liquid water, such as a desert or an ice- or snow-covered region.

Morphologically and physiologically the xerophytes are adapted to conserve water and also to store large quantities of water in the dry periods. Some species are adapted to survive long periods of dehydration in their tissues. During the periods of dehydration the metabolic activity of them may be shut down.

Morphological Adaptations in xerophytic plants

Almost all the xerophytic plants have similar shapes, structure and forms and they look very similar though these plants are not genetically related. This process of evolution is known as convergent evolution.

Reduction of Surface Area
  • Xerophytic plants usually have less surface area than other plants, this reduces the area that is exposed to the air and helps in reducing water loss by evaporation process.
  • These plants have smaller leaves and few branches than other plants.
Reduction in Air Flow
  • Some xerophytes plants have tiny hairs on their surface; this provides a wind break and reduces air flow, which reduces the rate of evaporation.
  • In such environments the region under the leaves/spines is the place of transpiration and this place is more saturated than the normal water vapor.
  • If there is less movement of air, there is reduced potential gradient of the water vapor hence reducing transpiration.
  • Spines trap moisture and also slow the movement of air over the tissues.
Reflectivity
  • The color of these plants or of the waxes or hairs on its surface may help to reflect sunlight and reduce evaporation.
  • Physiological Adaptations of Xeropyhtes
  • Some xerophytic plants store water in structures like roots, trunks, stems and leaves. Water is stored in swollen parts of the plant known as succulence. A swollen trunk part or the root part at the ground level of a plant is called caudex.
  • Stomata are tiny pores on the surface of xerophytic plants; they stay open only at night to reduce evaporation.
  • These plants may secrete resins and waxes on their surface which reduce evaporation.
  • Some plants drop their leaves in the times of dryness or they modify the leaves produced so that they are smaller and less surface area of the plants is exposed.
  • Xerophytic plants may go dormant and stop growing during dry periods; they may also change the kind of photosynthesis or they may change the storage allotment of the products of photosynthesis by growing new leaves to the roots.
  • Seeds also may be modified to require excessive amount of water before the process of germination, so to ensure that there is sufficient supply of water for the survival of the seedling.
  • So, the correct answer is 'Reduce loss of water'

In xerophytes, the osmotic concentration of cell sap is

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

  1. Less than normal

  2. Normal

  3. More than normal

  4. No osmotic pressure at all

Show answer
Correct Option: C
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.

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?

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

  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.

Show answer
Correct Option: D
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'.