Tag: botany

Questions Related to botany

A structure absent in monocot is

botany internal structure of root, stem and leaf internal structure of monocot stem internal structure of monocots internal structure of stem(dicot and monocot)

  1. Sieve tubes

  2. Stomata

  3. Cambium

  4. Vessels

Show answer
Correct Option: C
Explanation:

In monocot stem, epidermis, hypodermis, ground tissue, and vascular bundles are present. General cortex, endodermis, pericycle, medulla, medullary are absent. In the phloem, phloem parenchyma is also absent. Xylem and phloem are present on same radii, and also present side by side. So they are also called Collateral and Conjoint vascular bundles. In the vascular bundles, cambium is absent between xylem and phloem, So these are closed vascular bundles. In the xylem, protoxylem is towards the centre, and metaxylem is towards the periphery. So, it is an endarch xylem. 

So, the correct option is 'Pith or cambium'.

Which one is false about monocot stem?
I. Vascular bundles is scattered, cojoint, close, surrounded by sclerenchymatous bundle sheath and cavity.
II. Hypodermis is scelerenchymatous.
III. Peripheral vascular bundles is smaller than centrally placed ones.
IV. Ground tissue is differentiated into cortex, pericycle, pith, etc.
V. Homogeneous parenchymatous ground.

botany internal structure of root, stem and leaf internal structure of monocot stem internal structure of monocots internal structure of stem(dicot and monocot)

  1. I, III, IV

  2. III, IV

  3. IV

  4. V

Show answer
Correct Option: C
Explanation:

The monocot stem shows the following characteristics: 

I. Vascular bundles are scattered in the ground tissue, conjoint, collateral and they are surrounded by the sclerenchymatous layer of bundle sheath. They have a lysigenous cavity formed by the breakdown of inner protoxylem vessels and parenchyma.
II. The hypodermis is made up of sclerenchymatous cells.
III. The peripheral vascular bundles are smaller in size and are more than the central vascular bundles.
IV. Ground tissue is not differentiated into cortex, pericycle, pith etc.
V. Ground tissue is homogeneous and is made of parenchymatous cells.
Hence, the correct answer is 'Ground tissue is differentiated into cortex, pericycle, pith etc.'

Vascular bundles are scattered in

botany internal structure of root, stem and leaf internal structure of monocot stem internal structure of monocots internal structure of stem(dicot and monocot)

  1. Bryophytes

  2. Dicot root

  3. Dicot stem

  4. Monocot stem

Show answer
Correct Option: D
Explanation:

In monocot stems, the vascular bundles are dispersed. In dicot stems, the vascular bundles are arranged in ring.

Monocot characteristics are

botany internal structure of root, stem and leaf internal structure of monocot stem internal structure of monocots internal structure of stem(dicot and monocot)

  1. Fibrous root system, parallel-veined leaves, trimerous flowers and two cotyledons

  2. Fibrous root system, parallel-veined leaves, trimerous flowers and one cotyledon

  3. Fibrous root system, reticulate veined leaves, trimerous flowers and one cotyledon

  4. Tap root system, parallel venation, trimerous flowers and one cotyledon

Show answer
Correct Option: B
Explanation:

Monocot plants, as the name suggests have only one cotyledon. these plants have characteristic features like fibrous root system because the radicle is short-lived, thus replaced by adventitious roots. They also have parallel-veined leaves and trimerous flowers.

So the correct answer is 'Fibrous root system, parallel-veined leaves, trimerous flowers, and one cotyledon'.

Oil cavities of Citrus are

botany internal structure of root, stem and leaf internal structure of monocot stem internal structure of monocots internal structure of stem(dicot and monocot)

  1. Lysigenous

  2. Schizogeneous

  3. Schizolysigneous

  4. Intercellular spaces.

Show answer
Correct Option: A
Explanation:

Lysigenous intercellular spaces: These cavities of intercellular spaces store up water, gases and essential oils in them. The examples are commonly found in water plants and many monocotyledonous plants. The secretory cavities in Eucalyptus, Citrus and Gossypium are good examples.

So, the correct answer is 'Lysigenous.'

Belt's corpuscles occur on

botany ecological adaptations, succession and ecological services plant adaptation adaptation in plants plant habitat importance and classification of angiosperms

  1. Casuarina roots

  2. Casuarina leaves

  3. Leaves of Acacia sphaerocephala

  4. Roots of Acacia sphaerocephala

Show answer
Correct Option: C
Explanation:

Belt's corpuscles are certain corpuscles containing food secreted by the plants at the tips of their leaflets for ants to maintain myrmecophily. They are seen in leaves of acacia sphaerocephala as it is a myrmecophile.

So, the correct answer is 'Leaves of Acacia sphaerocephala'.

Which of the following is wrong about xerophytes?

botany ecological adaptations, succession and ecological services plant adaptation adaptation in plants plant habitat importance and classification of angiosperms

  1. Sunken stomata

  2. Small spiny leaves

  3. Thick cuticle

  4. Large number of stomata

Show answer
Correct Option: D
Explanation:

 Xerophytes show structural adaptations to discourage water loss through transpiration and increase water absorption. Such, adaptations include small spiny leaves, thick waxy cuticle on leaf surface, sunken stomata and well developed vascular tissue. Leaves show reduction in number of stomata to cut off transpiration losses of water. Also some succulents show 'Crassulacean Acid Metabolism (CAM)'. Their stomata open only during night.

Thus, the correct answer is option D.

The plants of this group are adapted to live partly in water and partly above substratum and free from water. Name the group.

botany ecological adaptations, succession and ecological services plant adaptation adaptation in plants plant habitat importance and classification of angiosperms

  1. Xerophytes

  2. Thalophytes

  3. Halophytes

  4. Hydrophytes

Show answer
Correct Option: C
Explanation:

Halophytes are plants adapted to grow in saline conditions. They grow in mangroves, coastal dunes and marshes. The environmental conditions are high salinity and high level of water. The lower parts of trees are permanently submerged in water and grow pneumatophores for gaseous exchange and respiration. The upper parts of these plants are not submerged and freely exposed to atmosphere.

Which of the following is not an adaptive feature of plants growing in physiologically dry soil?

botany ecological adaptations, succession and ecological services plant adaptation adaptation in plants plant habitat importance and classification of angiosperms

  1. Pneumatophore

  2. Vivivary

  3. Sunken stomata

  4. All of the above

Show answer
Correct Option: C
Explanation:

Physiologically dry soil means that water is present in soil but due to high levels of salt, it is not available to plants as plants cannot easily absorb the water present in soil. Such plants are called halophiles, e.g., mangrove plants like Sonnertia, Rhizophora, Avicennia etc. Such plants show several unique features such as presence of pneumatophores and vivipary. Sunken stomata is not shown by mangroves but is shown by xerophytes which grow in physically dry soil. Thus, the correct answer is option C.

Mature anther contains

botany male & female gametophytes: structure and development pollen grain androecium male gametophyte

  1. One wall layer, two microsporangia

  2. Two wall layers, one microsporangium

  3. Four wall layers and four microsporangia

  4. Two wall layers, four microsporangia

Show answer
Correct Option: C
Explanation:

Structure of anther contains four wall layers:-

i)Epidermis, endothecium and middle layer that function as a protective layer.
ii)Inner most layer tapetum provide nutrition to the pollen.
iii)It contains four microsporangia two in each lobe which give rise to microspore mother cell.
So the correct option is 'Four wall layers and four microsporangia'.