Tag: plant adaptation and modification

Questions Related to plant adaptation and modification

In some __, the leaf base may become swollen and is called as __.

  1. monocots, sheathing leaf base

  2. legumes, pulvinus

  3. legumes, sheathing leaf base

  4. monocots, pulvinus


Correct Option: B
Explanation:

Some plants are characterized by well-developed pulvini, small swelling at the base of the leaves, on the shoots. These leaves are individually attached, flattened and helically arranged. Pulvinus facilitates growth independent movement and is common in members of Fabaceae family.

So, the correct answer is " legumes, pulvinus ".

Leaves are modified for storage of food in

  1. Tridax

  2. Pea

  3. Onion

  4. Beans


Correct Option: C
Explanation:

A) Tridex is the flowering plant that belongs to family Asteraceae.

B) Onion is the modified leaves that become fleshy due to storage of water, mucilage and food materials.
C) Pea and beans are the legume plants that fix atmospheric nitrogen.
So, the correct option is 'Onion'.

The edible portion in a fresh onion comprises-

  1. modified leaves

  2. buds and leaf bases

  3. swollen stem

  4. disc-like stem


Correct Option: A
Explanation:

The onion is an underground stem. It is a stem modification thta gets modified to store food. There is a disc-like a stem which makes up e edible part of the onion. It is called a bulb.

So, the correct option is 'disc-like stem'

The tendril of sweet pea plant is modified 

  1. Auxiliary bud

  2. Stipule

  3. Terminal leaflet of compound leaf

  4. Aerial routs


Correct Option: C
Explanation:

The tendril of sweet pea is a modification of the terminal leaflet of the leaf into a slender wiry and coiled structure that helps in support of the plant.

So the correct option is 'Terminal leaflet of compound leaf'

Which of following is incorrect for trichomes?

  1. Trichomes are leaf modifications which minimize water loss

  2. Usually multicellular

  3. They may even be secretory

  4. Help in water absorption


Correct Option: A
Explanation:

  • Trichomes are the epidermal outgrowths on the vegetative and reproductive parts of the plant. 
  • These are hair-like structures which may be unicellular or multicellular.
  • Some trichomes are secretory in nature and are known as glandular trichomes. For example, tannins, resins, gum etc., are some products secreted by trichomes.
  • Trichomes help in the absorption of water and minerals.
It is not a leaf modification, hence, option A is incorrect. So, the correct answer is 'Trichomes are leaf modifications which minimize water loss'.

Find incorrect match.

  1. Fleshy leaves - onion

  2. Underground stem - Turmeric

  3. Racemose - Solanum

  4. Phylloclade - Euphorbia


Correct Option: C
Explanation:

  • The onion plant has bluish-green leaves and its bulb at the base of the plant begins to swell when a certain day-length is reached. The bulbs are composed of shortened, compressed, underground stems surrounded by fleshy modified scale leaves that envelop a central bud at the tip of the stem.
  • Underground stems are modified plant structures that derive from stem tissue but exist under the soil surface. Turmeric is the rhizome or underground stem.
  • In racemose inflorescence,  the growing region at the tip of the flower stalk continues to produce new flower buds during growth. As a result, the youngest flowers are at the top and the oldest flowers are at the base of the stalk. Mustard shows racemose inflorescence. Cyme inflorescence is present in Solanum. A Cyme is a group of flowers in which the end of each growing point produces a flower, so new growth comes from side shoots and the oldest flowers are at the top.
  • Phylloclade is a flattened branch or stem-joint resembling and functioning as a leaf. Phylloclade is a stem modification for deserts like area in which the stem becomes broad and fattened (in Opuntia) or cylindrical (in euphorbia)
So, the correct answer is 'Racemose - Solanum'.

The waxy material deposited in the casparian strip of the endodermis is

  1. Pectin

  2. Suberin

  3. Cellulose

  4. Lignin


Correct Option: B
Explanation:

  • Suberin is a cell wall constituent that forms gas and watertight layers. It is part of the Casparian strip of the root endodermis, where it acts as a diffusion barrier between the apoplast of the root cortex and the central cylinder.
  • Suberin is present in many C4 plants as an impermeable layer between the bundle sheath and mesophyll cells.
So, the correct option is 'Suberin'.

_________ traps the insect.

  1. Sunflower

  2. Tuberose

  3. Mimosa

  4. Venus fly trap


Correct Option: D
Explanation:

The venus fly trap which looks and smells like a flower to insects. When they land on it, they touch a trigger hair which slams the trap shut and they are then digested by the plant.

Insectivorous plants commonly grow in areas where soil is deficient in

  1. Carbon

  2. Nitrogen

  3. Potassium

  4. Phosphorus


Correct Option: B
Explanation:

The insectivorous plants are the carnivorous plants which feed on the insects. These plants have adapted to grow in the extreme conditions of the soil such as acidic pH. Generally, these plants are known to grow in the soil which is deficient in the mineral nutrients due to the presence of acid. The plant can grow in the soil which have low levels of nitrogen. 

Thus, the correct answer is option B. 

An example of a parasitic plant that is also strictly epiphytic is

  1. cuscuta(dodder)

  2. Viscum(mistletoe)

  3. Rafflesia

  4. Orobanche


Correct Option: B
Explanation:

  • Cuscuta is a large and widely distributed genus of twining leafless parasitic herbs.
  • Viscum is a common example of partial stem parasites, which grow as parasitic epiphytes on host plants. But it can carry out photosynthesis and manufacture their own food.
  • Rafflesia is a parasitic plant that lacks chlorophyll and contains a single very large flower.
  • Orobanche is the genus of more than 200 species of the parasitic nature plants.

So, option B is correct.