Tag: internal structure of dicot leaf

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Multiple choice botany internal structure of root, stem and leaf internal structure of monocot leaf internal structure of leaf (dicot and monocot) anatomy of leaf internal structure of dicot leaf

Match the columns.

A) Syntheticauxin  i) Zeatin 
B) Natural cytokinin from coconut milk  ii) IBA
C) naturalauxin  iii) Kinetin 
D) purine from herring sperm DNA iv) NAA
  1. $A-iv,B-i,C-ii,D-iii$
  2. $A-ii,B-i,C-iv,D-iii$
  3. $A-iv,B-iii,C-ii,D-i$
  4. $A-ii,B-iii,C-iv,D-i$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
 A synthetic auxin (NAA) suppresses secondary wall cellulose synthesis and enhances elongation in cultured cotton. Zeatin is a cytokinin derived from adenine, which occurs in the form of a cis- and a trans-isomer and conjugate. Five naturally occurring (endogenous)auxins in plants include indole-3-acetic acid, 4-chloroindole-3-acetic acid, phenylacetic acid, indole-3-butyric acid, and indole-3-propionic acid. The mechanism of production of kinetin in DNA is thought to be via the production of furfural — an oxidative damage product of deoxyribose sugar in DNA — and its quenching by the adenine base's converting it into N6-furfuryladenine, kinetin. So the correct option is
 ' A−iv,B−i,C−ii,D−iii'.
Multiple choice botany internal structure of root, stem and leaf internal structure of monocot leaf internal structure of leaf (dicot and monocot) anatomy of leaf internal structure of dicot leaf

Mark out the incorrect statements.


A) Bulliform cells are found on adaxial epidermis of grasses.
B) All vascular bundles have different size in leaf showing parallel venation.
C) Endodermis, pericycle, vascular bundle and pith constitute the stele.
D) Bastfibresare absent in primary phloem.

  1. B only

  2. D only

  3. A & B only

  4. B & C only
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Generally, the patterns of the leaf veins, or vascular bundles are pinnate and the veins are free; that is, they all diverge and never coalesce, either along their sides or at the ends. So, the incorrect statement is all vascular bundles have different size in leaf showing parallel venation.

Multiple choice botany internal structure of root, stem and leaf internal structure of monocot leaf internal structure of leaf (dicot and monocot) anatomy of leaf internal structure of dicot leaf

Dorsiventral leaf is identified by the presence of

  1. Stomata on both the epidermis

  2. Stomata mainly present on the lower epidermis

  3. No stomata on the epidermis

  4. Sunken stomata on the upper epidermis
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In dorsiventral leaf, epidermis is in two layers, one on each surface of the leaf. Both the layers are composed of compactly arranged, barrel-shaped cells. Intercellular spaces are absent. A cuticle surrounds both the layers. Multicellular hairs called as trichomes are present on both the layers. Stomata occur only in the lower epidermis. This condition is described as hypostomatic. 

Mesophyll is the ground tissue that occurs between the two epidermal layers. It is exclusively composed of chlorenchyma cells. The mesophyll is characteristically differentiated into two regions, namely an upper palisade parenchyma and a lower spongy parenchyma. Thus, option B is correct.

Multiple choice botany internal structure of root, stem and leaf internal structure of monocot leaf internal structure of leaf (dicot and monocot) anatomy of leaf internal structure of dicot leaf

Bulliform or motor cells occur in

  1. Upper epidermis of dicot leaves

  2. Upper epidermis of monocot leaves

  3. Lower epidermis of monocot leaves

  4. Lower epidermis of dicot leaves
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Bulliform cells or motor cells are large, bubble shaped epidermal cells that occur in groups on the upper surface of the leaves of many grasses. Loss of turgor pressure in these cells causes leaves to roll up during water stress. During drought, the loss of moisture through vacuoles induces bulliform cells to cause the leaves of many grass species to close as the two edges of the grass blade fold up toward each other. Once, adequate water is available, these cells enlarge and the leaves open again. Bulliform cells are absent in dicot leaves. 
Thus, the correct answer is option B.

Multiple choice botany internal structure of root, stem and leaf internal structure of monocot leaf internal structure of leaf (dicot and monocot) anatomy of leaf internal structure of dicot leaf

In isobilateral leaves

  1. Lower surface is brighter green

  2. Upper surface is lighter green

  3. Both the surfaces are equally green

  4. Upper surface is dark green while the lower surface is lighter green
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Leaves, in which both sides appear in equally green color are called isobilateral leaves. It is due to the presence of spongy parenchyma.

So, the correct option is ‘both the surface are equally green’.

Multiple choice botany internal structure of root, stem and leaf internal structure of monocot leaf internal structure of leaf (dicot and monocot) anatomy of leaf internal structure of dicot leaf

Many grass leaves are capable of folding and unfolding due to

  1. Parallel veins

  2. Isobilateral nature

  3. Thin lamina

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

Many grass leaves, folds during drought conditions and unfolds during moisturized conditions. It is due to the presence of large, thin-walled cells present on the adaxial side of the upper epidermis, called Bulliform cells.

So, the correct option is ‘Bulliform cells’.

Multiple choice botany internal structure of root, stem and leaf internal structure of monocot leaf internal structure of leaf (dicot and monocot) anatomy of leaf internal structure of dicot leaf

Ligule occurs on the leaf of

  1. Barley

  2. Oat

  3. Rice

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

The ligule is a part of the leaf that is found at the junction of the leaf blade and sheath of the leaf. It may take several forms. But commonly, it is a translucent membrane or a fringe of hairs. It is seen in plants belonging to the family Poaceae. Hence, ligule occurs on the leaf of Barley, Oat and Rice.

So, the correct answer is 'All of the above'.

Multiple choice botany internal structure of root, stem and leaf internal structure of monocot leaf internal structure of leaf (dicot and monocot) anatomy of leaf internal structure of dicot leaf

Leaves of many grasses are capable of folding and unfolding because they

  1. Are very thin

  2. Are isobilateral

  3. Have specialised bulliform cells

  4. Have parallel vascular bundles
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Grasses have monocot leaves. Leaves of grasses have specialized bulliform cells on the upper epidermis. These bulliform cells are capable of folding and unfolding of leaves to help in the process of transpiration. 

Thus, the correct answer is option C.

Multiple choice botany internal structure of root, stem and leaf internal structure of monocot leaf internal structure of leaf (dicot and monocot) anatomy of leaf internal structure of dicot leaf

Monocot leaves possess

  1. Intercalarly meristem

  2. Lateral meristem

  3. Apical meristem

  4. Mass meristem
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • The shoots can be categorized as long shoots and short shoots (on the basis of the distance between two nodes).
  • Internode is the length of the stem between two nodes.
  • The variable length of internodes in culm of sugarcane is mainly due to the presence of intercalary meristem (residual apical meristem).
  • An intercalary meristem is the meristems present at the base of the internodes of stem or leaf.
  • It helps in the elongation and growth of the plants at the nodes and internodes (stems and leaves).
  • In monocots such as in grasses it enables longitudinal growth of the leaves and in hollow stem or culm of bamboo and sugarcane, it helps in increasing the length of the stems.
  • So, the correct answer is 'Intercalary meristem'.