Tag: internal structure of root(dicot and monocot)

Questions Related to internal structure of root(dicot and monocot)

The number of xylem bundles in monocot roots are:

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

  1. 1

  2. 2

  3. 4

  4. 8

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Correct Option: A

Monocotyledonous root differs from dicot root in which of the following internal features (a to d)?


a. Presence of parenchymatous pericycle
b. Absence of fewer xylem bundles
c. Presence of large and well-developed pith
d. Presence of parenchymatous cortex without intercellular spaces

Find out the correct option.

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

  1. a, c, & d

  2. b & d

  3. b & c

  4. a & d

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Correct Option: A

Read the  following statements and choose the correct option. 
a) Pith is large and well developed in roots of monocot plants.
b) Bundle sheath is  presents in dicot stem.
c) Water containing cavities are present within vascular bundles of monocot stem.

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

  1. Only (b) is incorrect

  2. Only (a) is incorrect

  3. Only (a) and (b) are correct

  4. All (a), (b) and (c) are correct

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Correct Option: A
Explanation:

 In dicot stem, bundle sheath is absent, while in monocot stem the bundle sheath is present as it surrounds the scattered vascular bundles. So the correct option is 'Only (b) is incorrect'.

A typical monocotyledonous root is characterized by 

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

  1. Usually more than six xylem bundles

  2. Large and well developed pith

  3. No secondary growth

  4. All of the above

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Correct Option: D
Explanation:
A typical monocotyledonous root can be characterized by :-
1) The xylem shows a polyarch condition where it forms numerous groups or bundles (usually 12 to 21).
2) The cambium is absent in all the stages and there is no secondary thickening in such roots.
3) The pith is large and well developed.
So, the correct answer is 'All of the above'.

Bundle sheath cells are similar to mesophyll cells in 
a. Having grana.
b. Having large number of chloroplasts
c. Being involved in $CO _2$ fixation
d. Being impervious to gaseous exchange
e. Their primary $CO _2$ fixation product.

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

  1. Only c& e

  2. Only c

  3. Only a,b& e

  4. Only a & d

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Correct Option: A

The character of monocot is

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

  1. Net-veined leaves

  2. Annual rings

  3. Seed with two masses of stored food

  4. Conducting strands scattered in ground tissue

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Correct Option: D
Explanation:

Net-veined leaves, annual rings and seed with two masses of stored food are characteristic features of dicots. 

In a monocotyledenos, the vascular bundles are not arranged in a circle but are usually scattered throughout the ground tissue. There is no clearly defined pith as there is in many dicotyledonous species. The vascular bundles of monocotylenous plants do not contain a layer of meristematic tissue (cambium) as the dicots do. Thus, no new cells can be formed inside the vascular bundles of monocots and their vascular bundles are termed as closed, whereas those of dicot plants are open. 

In monocots, root cap is formed by

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

  1. Dermatogen

  2. Calyptrogen

  3. Wound cambium

  4. Vascular cambium

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Correct Option: B
Explanation:

Dermatogen is the histogen or meristematic regions of root and stem which is produced by apical meristem and give rise to uniseriate epidermis by anticlinal divisions; option A is incorrect. Monocotyledons have one additional histogen along with dermatogens, periblem and plerome Calyptrogen being the fourth one that makes root cap. The vascular cambium, also called as wood cambium, has thin walled highly vacuolated cells of two types, the fusiform initials and the ray initials. The fusiform initials are the elongated cells that give rise to secondary xylem and secondary phloem. Ray initials are horizontally organized and produce vascular rays (medullary rays or ray parenchyma). 

Thus, the correct answer is option B.

Monocot root differs from dicot root in having

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

  1. Open vascular bundle

  2. Scattered vascular bundle

  3. Large pith

  4. No pit

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Correct Option: C
Explanation:

Pith is the innermost region of the root representing the central axis. It is composed of few loosely arranged parenchyma cells. Large pith is present in monocot roots. In dicot roots, pith is absent. Open vascular bundles are present in dicots. Scattered vascular bundles are present in moncot stem. Radial vascular bundles are present in both monocot and dicot roots.

Thus, the correct answer is option C.

Polyarch and exarch vascular bundles are the characteristic of

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

  1. Dicot stem

  2. Dicot root

  3. Monocot stem

  4. Monocot root

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Correct Option: D
Explanation:

Monocot root vascular bundles are radial in arrangement. There are eight bundles each of xylem and phloem. Hence, the condition is described as polyarch. Xylem is described as exarch in them. 

Monocot stem vascular bundles are conjoint, collateral and closed. Xylem is endarch in them. Presence of only two protoxylem and two metaxylem vessels in each bundle. 
Dicot root vascular bundles are described as radial and tetrarch. There are four bundles each of xylem and phloem occurring alternately. Xylem is described as exarch. 
Dicot stem vascular bundles are eight in number, arranged in form of a broken ring. The vascular bundles are conjoint, collateral and open. Xylem is on the inner surface and phloem on the outer surface. Xylem is described as endarch. Thus, option D is correct.

Which of the following is correct sequence of layers in typical monocot root from outside to inside?

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

  1. Pericycle, cortex, endodermis, epiblema

  2. Epiblema, endodermis, cortex, pericycle

  3. Epiblema, cortex, endodermis, pericycle

  4. Epiblema, pericycle, cortex, endodermis

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Correct Option: C
Explanation:

The sequence of layers in typical monocot root from outer surface to inside is epiblema, cortex, endodermis, stele, pericycle, conjunctive tissue, pith and vascular bundles. Thus, option C is correct.