Tag: internal structure of monocot stem

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

The character of monocot is

  1. Net-veined leaves

  2. Annual rings

  3. Seed with two masses of stored food

  4. Conducting strands scattered in ground tissue
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In a monocotyledenous stem 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. 

As in the dicots the xylem of the bundles is pre-orientated toward the middles of the stem. 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 closed whereas those of dicot plants are open. So, no annual rings in monocots as, there is no secondary growth. 
Net veined leaves and seed with two masses of stored food are characteristics of dicots. Thus, option D is correct.

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

An example of monocots showing secondary growth in stem is

  1. Lilium

  2. Cocos

  3. Asparagus

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

Secondary growth is increase in the circumference / girth of the plant organs due to the formation of secondary tissues in stelar and extra stelar regions. Normally secondary growth takes place in roots and stem of dicotyledons and gymnosperms. Due to lack of cambium in monocotyledons, secondary growth is absent. But exceptionally, secondary growth takes place in some monocotyledons, such as palm, Yucca, Dracaena etc. 

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

Conjoint, collateral and closed vascular bundles are found in

  1. Monocot stem

  2. Monocot root

  3. Dicot stem

  4. Dicot root
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In monocot stem vascular bundles are found irregularly scattered in the ground tissue. Towards the periphery, the bundles are smaller in size, while towards the centre, they are larger in size. The smaller bundles are younger, while the larger ones are older. Hence, the arrangement is described as centrifugal. 

Each vascular bundle has a covering called as 'bundle sheath' formed by a single layer of sclerenchyma cells. 
The vascular bundle encloses both xylem and phloem. Xylem is found towards the inner surface and phloem towards the outer surface. Cambium is absent. Hence, the vascular bundles are described as conjoint, collateral and closed. 

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

Cambium found in vascular bundles of dicot stem is _______________.

  1. Intercalary meristem

  2. Fascicular cambium

  3. secondary meristem

  4. All of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Fascicular cambium is present in vascular bundles of dicot stem.  It is present between xylem and phloem of vascular bundle. 
So, the correct answer is 'Fasicular cambium'
Multiple choice botany internal structure of root, stem and leaf internal structure of monocot stem internal structure of monocots internal structure of stem(dicot and monocot)

Atactostele is found in

  1. Dicot stem

  2. Monocot stem

  3. Dicot root

  4. Monocot root
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Atactostele is a type of eustele, found in monocots, in which the vascular tissue in the stem exists as scattered bundles. Most seed plant stems possess a vascular arrangement, which has been interpreted as a derived siphonostele and is called as eustele. There is also a variant on the eustele found in monocots, like maize and rye. The variation has numerous scattered bundles in the stem and is called as an atactostele.

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

The stele present in Equisetum is

  1. Haplostele

  2. Actinostlele

  3. Plectostele

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

  1. Haplostele consist of smooth ore of xylem which is surrounded by a phloem ring.ex-Seleginella
  2. Actinostele consist of star shape xylem core with many radiating arms.ex-Lycopodium
  3. Plectostele consist of xylem core broken into a number of parallel plates.ex-Lycopodium clavatum
  4. Siphonostele is a protostele with central pith and considered to be the most advance stele.ex-Equisetum.
So the correct option is "Siphonostele".

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

Which of the following tissue is absent in vascular bundles of monocot stem?

  1. Xylem

  2. Phloem

  3. Cambium

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

In monocots, xylem and phloem are organized in vascular bundles scattered throughout the stem. As the plant grows, monocot stems generate new vascular bundles for the new tissue. Monocot stems in general possess a simpler arrangement than that found in dicots; the main elements of the stem are merely the vascular bundles and the pith that surrounds them.
Multiple choice botany internal structure of root, stem and leaf internal structure of monocot stem internal structure of monocots internal structure of stem(dicot and monocot)

Which of the following would you consider to prove that a plant is a monocot?

  1. Leaves with reticulate venation

  2. Taproot system

  3. Vascular bundles are closed

  4. Presence of cambium
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In the monocots, the vascular bundles are of the collateral and closed type. The closed vascular bundles lack the cambium and cannot show secondary growth. In the stem, vascular bundles are found scattered in the ground tissue. They are more in number at the periphery as compared to the centre. In the monocot roots, the vascular bundles are closed type an found in the stele.

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

Conjoint and closed vascular bundles with no phloem parenchyma may be observed in

  1. Monocot stem

  2. Monocot root

  3. Dicot stem

  4. Dicot root
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In monocot stem, all the vascular bundles, the xylem and phloem are in the same line; cambium is absent; phloem is external to xylem; protoxylem faces the centre. Hence, the vascular bundles are described as conjoint, collateral, endarch and closed.  

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

Hypodermis in monocotyledonous stem is?

  1. Parenchymatous

  2. Chlorenchymatous

  3. Collenchymatous

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

The region present below the epidermis in monocot stem is hypodermis. It is composed with sclerenchyma. Sclerenchyma is dead mechanical tissue. It provides mechanical strength to the stem.

So, the correct option is 'Sclerenchyma’.