What happens in plants during vascularisation:
- Differentiation of procambium, formation of primary phloem followed by formation of primary xylem
- Differentiation of procambium followed by the formation of primary phloem and xylem simultaneously
- Formation of procambium,primary phloem and xylem simultaneously
- Differentiation of procambium followed by the formation of secondary xylem
The Correct Option is B
Solution and Explanation
Vascularization refers to the process of vascular bundle formation from procambium in plants. Initially, thin-walled, elongated procambium strands are generated during early growth and differentiation. These strands subsequently undergo immediate differentiation, giving rise to both primary xylem and primary phloem simultaneously. Following procambium development, primary vascular tissues are formed. It's important to note that secondary xylem arises from the vascular cambium during secondary growth, rather than originating directly from procambium.
So, the correct option is (B): Differentiation of procambium followed by the formation of primary phloem and xylem simultaneously
Top Questions on Anatomy of Flowering Plants
- Assertion (A): Dicot leaf is dark green in colour on the upper surface and light green in colour on the lower surface.
Reason (R): Palisade tissue is at the abaxial side and spongy tissue is at the adaxial side in this leaf.
Identify the correct option from the following:- AP EAPCET - 2025
- Botany
- Anatomy of Flowering Plants
- Assertion (A): The functions of sieve tubes are controlled by the nucleus of companion cells. The companion cells help in maintaining the pressure gradient in sieve tubes.
Reason (R): Gymnosperms phloem has albuminous cells and sieve cells.
Identify the correct option from the following:- AP EAPCET - 2025
- Botany
- Anatomy of Flowering Plants
- Identify the tissues in correct sequence based on the given characters
A) Cell walls are thickened with cellulose, hemicellulose and pectin.
B) Cellulose walls Polygonal and perform photosynthesis.
C) Thickened and lignified cell walls with pits. Options :- AP EAPCET - 2025
- Botany
- Anatomy of Flowering Plants
- Choose the correct statements:
I. Phellogen made up of narrow thin-walled rectangular cells
II. Soft bark is formed early in the season
III. More xylem vessels with narrow lumen are called late wood
IV. In isobilateral leaf, mesophyll is differentiated- AP EAPCET - 2025
- Botany
- Anatomy of Flowering Plants
- Assertion (A): Trichomes help in preventing water loss due to transpiration.
Reason (R): The specialized cells near the guard cells together constitute stomatal apparatus.- AP EAPCET - 2025
- Botany
- Anatomy of Flowering Plants
Questions Asked in NEET exam
A sphere of radius R is cut from a larger solid sphere of radius 2R as shown in the figure. The ratio of the moment of inertia of the smaller sphere to that of the rest part of the sphere about the Y-axis is :
- NEET (UG) - 2025
- Moment Of Inertia
The current passing through the battery in the given circuit, is:
- NEET (UG) - 2025
- Current electricity
A bob of heavy mass \(m\) is suspended by a light string of length \(l\). The bob is given a horizontal velocity \(v_0\) as shown in figure. If the string gets slack at some point P making an angle \( \theta \) from the horizontal, the ratio of the speed \(v\) of the bob at point P to its initial speed \(v_0\) is :
- NEET (UG) - 2025
- Pendulums
- Two cities X and Y are connected by a regular bus service with a bus leaving in either direction every T min. A girl is driving scooty with a speed of 60 km/h in the direction X to Y. She notices that a bus goes past her every 30 minutes in the direction of her motion, and every 10 minutes in the opposite direction. Choose the correct option for the period T of the bus service and the speed (assumed constant) of the buses.
- NEET (UG) - 2025
- Relative Velocity
- The intensity of transmitted light when a polaroid sheet, placed between two crossed polaroids at \(22.5^\circ\) from the polarization axis of one of the polaroids (\(I_0\) is the intensity of polarised light after passing through the first polaroid):
- NEET (UG) - 2025
- Polarization
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.