Question:
Secondary xylem and phloem in dicot stem are produced by
Secondary xylem and phloem in dicot stem are produced by
Updated On: Apr 13, 2026
- Axillary meristems
- Apical meristems
- Phellogen
- Vascular cambium
Show Solution
Verified By Collegedunia
The Correct Option is D
Solution and Explanation
??Vascular cambium is partially secondary
??Form secondary xylem towards its inside and secondary phloem towards outsides.
??$4 - 10$ times more secondary xylem is produced than secondary phloem.
Was this answer helpful?
0
0
Top NEET Biology Questions
- Name the class of enzyme that usually catalyzes the following reaction: \[ S - G + S^{\prime} \rightarrow S + S^{\prime} - G \] Where \( G \) represents a group other than hydrogen, \( S \) is a substrate, and \( S^{\prime} \) is another substrate.
- Given below are two statements: Statement I: In the RNA world, RNA is considered the first genetic material evolved to carry out essential life processes. RNA acts as a genetic material and also as a catalyst for some important biochemical reactions in living systems. Being reactive, RNA is unstable.
Statement II: DNA evolved from RNA and is a more stable genetic material. Its double helical strands being complementary, resist changes by evolving repair mechanisms. In the light of the above statements, choose the most appropriate answer from the options given below:- NEET (UG) - 2025
- Biology
- Structure of DNA and RNA
- Match List - I with List II
List I List II A. The Evil Quartet III. Causes of biodiversity losses B. Ex situ conservation I. Cryopreservation C. Lantana camara II. Alien species invasion D. Dodo IV. Extinction - Which of the following enzyme(s) are NOT essential for gene cloning?
A. Restriction enzymes
B. DNA ligase
C. DNA mutase
D. DNA recombinase
E. DNA polymerase- NEET (UG) - 2025
- Biology
- Molecular Biology
- With the help of the given pedigree, find out the probability for the birth of a child having no disease and being a carrier (has the disease mutation in one allele of the gene) in the F3 generation.
- NEET (UG) - 2025
- Biology
- Genetics
View More Questions
Top NEET Secondary Growth Questions
Identify the correct statements:
A. Lenticels are the lens-shaped openings permitting the exchange of gases.B. Bark formed early in the season is called hard bark.C. Bark is a technical term that refers to all tissues exterior to vascular cambium.D. Bark refers to periderm and secondary phloem.E. Phellogen is single-layered in thickness.Choose the correct answer from the options given below:
- NEET (UG) - 2023
- Biology
- Secondary Growth
Match List - I with List - II.
List - 1 List - 1 a Lenticels i Phellogen b Cork cambium ii Suberin deposition c Secondary cortex iii Exchange of gases d Cork iv Phelioderm Choose the correct answer from the options given below.
- NEET (UG) - 2021
- Biology
- Secondary Growth
- Plants having little or no secondary growth are
- NEET (UG) - 2018
- Biology
- Secondary Growth
- The vascular cambium normally gives rise to :
- NEET (UG) - 2017
- Biology
- Secondary Growth
Top NEET Questions
Identify the correct orders against the property mentioned:
A. H$_2$O $>$ NH$_3$ $>$ CHCl$_3$ - dipole moment
B. XeF$_4$ $>$ XeO$_3$ $>$ XeF$_2$ - number of lone pairs on central atom
C. O–H $>$ C–H $>$ N–O - bond length
D. N$_2$>O$_2$>H$_2$ - bond enthalpy
Choose the correct answer from the options given below:- NEET (UG) - 2025
- Chemical bonding and molecular structure
- A microscope has an objective of focal length \(f_o = 2\) cm and an eyepiece of focal length \(f_e = 4\) cm. The tube length of the microscope is \(L = 40\) cm. If the distance of distinct vision of eye is \(D = 25\) cm, the magnification in the microscope is:
- NEET (UG) - 2025
- Optical Instruments
- Name the class of enzyme that usually catalyzes the following reaction: \[ S - G + S^{\prime} \rightarrow S + S^{\prime} - G \] Where \( G \) represents a group other than hydrogen, \( S \) is a substrate, and \( S^{\prime} \) is another substrate.
- Given below are two statements: Statement I: In the RNA world, RNA is considered the first genetic material evolved to carry out essential life processes. RNA acts as a genetic material and also as a catalyst for some important biochemical reactions in living systems. Being reactive, RNA is unstable.
Statement II: DNA evolved from RNA and is a more stable genetic material. Its double helical strands being complementary, resist changes by evolving repair mechanisms. In the light of the above statements, choose the most appropriate answer from the options given below:- NEET (UG) - 2025
- Structure of DNA and RNA
- Given below are two statements:
Statement I: A hypothetical diatomic molecule with bond order zero is quite stable.
Statement II: As bond order increases, the bond length increases.
In the light of the above statements, choose the most appropriate answer from the options given below:- NEET (UG) - 2025
- Chemical bonding and molecular structure
View More Questions
Concepts Used:
Secondary Growth
Secondary growth is an increase in girth of thickness of the axis due to activity of lateral meristem. The tissues involved in secondary growth are two lateral meristems are vascular cambium and cork cambium.
Secondary Growth in Stem:
Formation of Cambium Ring-
- The cambium present between the xylem and phloem in vascular bundles is called Fascicular or Interfascicular cambium.
- In secondary growth, few medullary ray cells that are located between vascular bundles also become meristematic, and it is known as Interfascicular cambium.
Formation of the secondary tissues-
- The cambium ring cuts off cells on both sides. It produces secondary phloem outwardly and secondary xylem inwardly.
- The amount of secondary xylem cut off is more than the secondary phloem.
Secondary Growth in Root:
Vascular Cambium-
- The cambium is absent initially but develops later at the time of secondary growth.
- The pericycle cells lying outside the protoxylem and the conjunctive parenchyma cells on the lateral side of the phloem bundle become meristematic to form many cambial strips.
Cork Cambium-
- The cork cambium develops because of the tangential division of cells of the pericycle.
- The activity of cork cambium is like that found in the dicot stem, so it produces cork cells or phellem towards the outside and phelloderm or secondary cortex towards the inside.
Abnormal secondary growth:
- Due to absence of the cambium in monocots, monocots don’t show secondary growth and the vascular system is totally composed of primary tissues.
- The vascular bundles are irregularly scattered in the ground tissues, such that the cortex and other ground tissues can’t be differentiated.
- Dracaena, Yucca, Agave are examples of monocots that exhibit a peculiar type of secondary growth in thickness.