Tag: internal structure of root, stem and leaf

Questions Related to internal structure of root, stem and leaf

A common character of monocot and dicot roots 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. Exarch protoxylem

  2. Endarch xylem

  3. Number of xylem strands

  4. Occurrence of secondary growth

Show answer
Correct Option: A
Explanation:

The anatomy of dicot root and monocot root more or less similar in majority of characters. They are epidermis, general cortex, endodermis, type of vascular bundles, nature of xylem.

The common characters appear between the anatomy of dicot root and monocot root are 
Presence of single-layered epidermis
Presence of parenchymatous general cortex
Presence of single-layered endodermis with Casparian bands.
Presence of radial vascular bundles
Presence of exarch xylem.
So, the correct option is 'Exarch protoxylem'.

Pick u the wrong differences between dicot and monocot root.

Character Dicot Root Monocot Root
(a) Activity of pericycle Lateral root production Secondary growth and cambium
(b) Vascular bundle Diarch to tetrarch Polyarch
(c) Cambium Lateral, developed Absent
(d) Pith Well developed Poorly developed
botany internal structure of root, stem and leaf internal structure of monocot root internal structure of root(dicot and monocot) anatomy of root

  1. b, d

  2. a, c

  3. a, d

  4. a, b

Show answer
Correct Option: C
Explanation:

a) Wrong – because in dicot root pericycle is meant for production of lateral roots and cambium whereas in monocot root it is pericycle is meant for lateral production only.

b) True – In dicot root stele is diarch to tetrarch, whereas in monocot root, stele is polyarchy.

c) True – In dicot root, cambium is developed laterally, whereas in monocot root, cambium is absent.

d) False – because, in dicot root is pith is poorly developed, whereas in monocot root pith is well developed.

So, the correct option is ‘a,d’.

Which plant part possesses polyarch condition of vascular bundles with a well developed pith?
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 root

  2. Monocot root

  3. Dicot stem

  4. Monocot stem

Show answer
Correct Option: B
Explanation:

A monocot root possesses polyarch (more than 4) condition of vascular bundle, here the vascular bundles are radial, closed with exarch condition of the xylem, embedded in the ground tissue that has a well developed central region or the pith or medulla.

So, the correct answer is 'Monocot root'

Polyarch vascular bundles generally occur in
botany internal structure of root, stem and leaf internal structure of monocot root internal structure of root(dicot and monocot) anatomy of root

  1. Monocot stem

  2. Dicot stem

  3. Dicot root

  4. Monocot root

Show answer
Correct Option: D
Explanation:

Polyarch vascular bundle (more than 4)  is observed in monocot root. The vascular bundle is radial and closed, with exarch condition of the xylem. 

So, the correct answer is 'Monocot root'

A typical monocotyledonous root is characterised 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 these

Show answer
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'.

Read the following statements :
(i). In monocot root, a large number of vascular bundles are arranged in the form of a ______ around the central ____
(ii). Due to the presence of _, the endodermal cells do not allow wall to wall movement of substances between cortex and pericycle, in a primary dicot root.
(iii). The epidermis of stem of sunflower bears several unbranched _____ hair.
(iv). The central portion of a dicot stem is usually occupied by ______ comprising of thin-walled parenchymatous cells
Select the option that correctly fills the blanks in any two of them.

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

  1. (i) ring, pith; (ii) hypodermis

  2. (ii) Casparian strips; (iii) unicellular

  3. (i) ring, cortex; (iv) vascular bundles

  4. (iii) multicellular; (iv) pith

Show answer
Correct Option: D
Well developed pith is found in
botany internal structure of root, stem and leaf internal structure of monocot root internal structure of root(dicot and monocot) anatomy of root

  1. Monocot root and monocot stem

  2. Monocot stem and dicot root

  3. Monocot root and dicot stem

  4. Dicot root and dicot stem

Show answer
Correct Option: C
Explanation:

Well developed pith or parenchymatous central region is present in monocot root (maize) and dicot stem (Sunflower). Its a structure of loosely arrannged cells that embeds vascular tissue, it may store food.

So, the correct answer is 'Monocot root and dicot stem'

Polyarch condition is found in

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

  1. Monocot root

  2. Dicot root

  3. Monocot stem

  4. Dicot stem

Show answer
Correct Option: A
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 monocot root. 

Monocot stem vascular bundles are conjoint, collateral and closed with endarch xylem. 
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. 

Passage cells are more distinct in endodermis 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. Monocot stem

  3. Dicot root

  4. Monocot root

Show answer
Correct Option: D
Explanation:

Passage cells are endodermal cells of older roots, which have retained thin walls and Casparian strips rather than becoming suberized and waterproof like the other cells around them, to continue to allow some symplastic flow to the inside. 

Passage cells function to allow transfer of solutes, such as calcium and magnesium into the stele, in order to eventually reach the transpiration system.
Passage cells are more distinct in endodermis of monocot root and absent in dicot root, monocot stem and dicot stem. Thus, option D is correct.

Polyarch and exarch condition of found in

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

  1. Monocot stem

  2. Monocot root

  3. Dicot stem

  4. Dicot root

Show answer
Correct Option: B
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. 

Monocot stem vascular bundles are numerous in number and the xylem is endarch. 
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. 
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.