Tag: anatomy of stem

Questions Related to anatomy of stem

In dicot stem, lateral branch comes out from 

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

  1. Pericycle

  2. Cortex

  3. Pith

  4. Epidermis

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Correct Option: B
Explanation:

In dicot stem, the lateral branches are exogenous in origin and they come out from the cortex of the stem. However, in dicot root, the lateral roots are endogenous in origin because they come out from the pericycle of the stem.

A. Pericycle gives rise to the lateral roots.
B. Cortex gives rise to the lateral branches in stem.
C. Pith is a storage organ.
D. Epidermis gives rise to scales and trichomes.
Hence, the correct answer is 'Cortex'

In young dicot stem, cambium is

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

  1. Single layered

  2. Double layered

  3. Multilayered

  4. Absent

Show answer
Correct Option: A
Explanation:

In a young dicot stem, the cambium is single layered. It is made by the intrafascicular cambium present within the vascular bundles and the dedifferentiation of the parenchyma cells of the medullary rays between the vascular bundles, called interfascicular cambium. Their combination gives a circular cambium that produces xylem elements on the inner side and the phloem elements on the outer side.

Hence, the correct answer is 'Single layered'

In dicot stem, cork cambium develops in 

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

  1. Epidermal region

  2. Cortical region

  3. Stelar region

  4. Vascular region

Show answer
Correct Option: A
Explanation:

Cork cambium is secondary or lateral meristematic tissue that grows beneath the epidermis and replaces it in dicot roots and stems and is responsible for the secondary growth of the tree.

So the correct option is 'Epidermal layer'

The nature of pericycle above the phloem in dicot stem is 

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

  1. Parenchymatous

  2. Sclerenchymatous

  3. Collecnchymatous

  4. Chlorenchymatous

Show answer
Correct Option: B
Explanation:

The pericycle is a thin layer located between the endodermis and phloem in plant roots. In dicot stems, it is located around the ring of vascular bundles in the stele. The nature of pericycle is sclrenchymatous. 

Thus, the correct answer is 'Sclerenchymatous.'

Ploem fibre (Bast fibre) are generally absent in 

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

  1. Dicot

  2. Primary Phloem

  3. Secondary Phleom

  4. Both (2) and (3)

Show answer
Correct Option: B
Explanation:

Bast fibers are made up of sclerenchymatous cells and are absent in primary phloem but present in secondary phloem of dicots and are elongated , unbranched and have pointed needle like apices and are devoid pf protoplasm at maturity and dead.

So the correct option is 'Primary Phloem'.

Which of the following statement is incorrect?

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

  1. In a dicot stem, the pericycle is usually multilayered

  2. Wood is the common name used for secondary xylem

  3. Peripheral cytoplasm, a large vacuole and a prominent nucleus: all are absent in a mature sleve tube elements

  4. Lenticels are the aerating pores present in bark of plants and are associated with gaseous exchange

Show answer
Correct Option: A
Explanation:
  • Pericycle is a cylinder of parenchymal and sclerenchyma cells which lie just below the endodermis of the plants. 
  • In dicot stem, the pericycle is heterogenous made of parenchyma and sclerenchyma alternatively in irregular patches but they are not multilayered.
  • So, the correct answer is 'In a dicot stem, the pericycle is usually multilayered'.

Choose incorrect statement from the given below

I. In dicot stem, the innemost layer of cortex is endodermis.
II. Endodermis with casparian strips is found in dicot stem.
III. In dicot stem, the cells of endodermis are rich in starch grain.

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

  1. I & II

  2. II &III

  3. I & III

  4. Only II

Show answer
Correct Option: D

Which is NOT TRUE for anatomy of the Dicot stem?

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

  1. Hypodermis is collenchymatous

  2. Vascular bundles are arranged in a ring

  3. Vascular bundles are conjoint and closed

  4. Phloem parenchyma is present

Show answer
Correct Option: A

Casparian strips occur in

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

  1. Radial walls of endodermis

  2. Radial walls of phellem cells

  3. Radial walls of epidermal cells

  4. None of the above

Show answer
Correct Option: A
Explanation:

Casparian strips occur in radial walls of endodermis. The Casparian strip is a band of cell wall material deposited on the radial and transverse walls of the endodermis, and is chemically different from the rest of the cell wall - the cell wall being made of lignin and without suberin - whereas, the Casparian strip is made of suberin and sometimes lignin. It blocks the passive flow of materials such as water and solutes into the stele of a plant.
Thus, the correct answer is option A.

Distinguishing feature of closed vascular bundle is

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

  1. Presence of cambium

  2. Absence of cambium

  3. Ring of vascular bundles

  4. No vascular bundles

Show answer
Correct Option: B
Explanation:

Open vascular bundle contains an interfascicular cambium in between phloem and xylem. Phloem and xylem are not in direct contact with each other. 

In closed vascular bundle interfascicular cambium is absent. There is direct contact between phloem and xylem.