The Leaf: Morphology, Venation, Types & Phyllotaxy – NEET Biology Notes
Welcome to Chaubey Biology Hub, your premier destination for high-quality, NCERT-aligned medical entrance preparation. We take pride in delivering content that doesn't just mirror textbooks but decodes them. This guide on Root and Stem Morphology is meticulously crafted to meet the rigorous standards of the NTA NEET-UG syllabus, focusing exclusively on the core concepts that matter most."
Before exploring the anatomical details of the Morphology of Flowering Plants: The Leaf: Morphology, Venation, Types & Phyllotaxy – NEET Biology Notes ensure you have reviewed our previous post on Morphology of Flowering Plants: Root & Stem NCERT Notes + Practice MCQs for NEET to understand the evolutionary context of flowering plants (Angiosperms) in the NEET journey."
Table of content
- Introduction to the Leaf
- Parts of a Typical Leaf
- Modifications of Leaves
- Types of Leaves (Simple & Compound)
- Venation: The Arrangement of Veins
- Phyllotaxy: Arrangement of Leaves on Stem
- NEET Practice MCQs
Introduction to the Leaf
- Leaf is an important part in plant. It perform the photosynthesis as well as bear stomata for gaseous exchange.
- The leaf is green and flat structure present on stem.
- Biologically it is originated from the node of stem and bear buds in its axil. This axillary bud in future is transformed into a new branch.
- Leaf is developed from the activity of shoot apical meristem and arranged in acropetal order. Leaves are important vegetative organ for Photosynthesis.
Did You Know?
While the Leaf is known as the "Kitchen of the Plant" in higher plants, do you know which organisms first started Oxygenic Photosynthesis according to the Five Kingdom System?
To find the answer and master concepts like Monera, Protista, and Viruses, check out our comprehensive guide here:
Parts of Typical leaf :
- There are prominently three part of a typical leaf - Leaf base, petiole and leaf lamina ( leaf blade )
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| Leaf and its Parts |
- In Monocot plants like Maize and sugar cane , the leaf base is grow and make a cover for stem which cover stem completely or partially
- In Legume plant like Pea, Gram leaf base get swollen and form a structure called pulvinus.
- The petiole help hold the leaf blade.
- Petiole allow the leaf blade to flutter in wind . By this activity of petiole, leaf get cooling and. Fresh air may enter into leaf surface.
💡NEET Tip
📝 The leaf is attached with the stem by the Leaf base also bear paired small leaf life appendages called stipules
- Leaf blade also called leaf lamina. It is most expanded part of leaf and bear stomata.
- Leaf blade also bear vein and veinlet. The thick and centrally located vein is termed midrib. Vein provide rigidity for the leaf blade.
💡NEET Tip
📝 Vein act as channel for transport of water mineral and food material.
Types of Leaf :
- A leaf may be simple or compound. When incision or cut portion of leaf blade do not touch the mid rib than leaf is simple.
- When incision or cut portion of leaf blade touch the mid rib and leaf blade is divided into large number of leaflets than leaf is compound.
- Compound leaf may be pinnately or palmately.
- When leaflets are present on common rachis which may represent mid rib called pinnately compound leaf. For example - Neem.
NEET often asks comparative questions, like the difference between the pinnate leaves of Cycas and the leaves of higher Dicots. If you are confused about these botanical differences, refer to our detailed classification notes here:
- When leaflets are originated from a common point at tip of petiole called palmately compound leaf. For Example : Silk cotton
- A bud is present in axil of petiole of both simple or compound leaves. This bud is absent in leaflet of compound leaves.
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| Types of Leaf |
Modification of leaf :
- When leaf perform other function like support, storage of food, protection, etc than the photosynthesis called modification of leaf.
- In Garden pea, leaf is modified into tendril for the climbing with the external support.
- In Cactus and Opuntia leafs are modified into spines for the defense against browsing animal.
- In Australian Acacia , leaves are short lived and its petiole become green to synthesized food.
💡Know it Also .
📝 In insectivorous plants like Napenthes or pitcher plant , Venus fly trap or Dionea the leaves are modified into a pitcher like structure to catch the and digest the insect.
📝 These plant digest insect to fulfil their nitrogen requirement.
- In Onion or Garlic, leaves are modified into swollen structure because it store food.
- The arrangement of veins in the leaf blade or lamina is called venation.
- Initially this arrangement is directly related to taxonomic significance.
- Later on this system has been related with the water relations and has great importance with ecological research.
- Venation is of two types namely Reticulate venation and Parallel venation
Reticulate Venation
- It is common in all dicot leaves. In this type of venation there is a prominent vein called the midrib in the center .
- This midrib gives rise to multiple small veins which finally form a network like mesh structure in the lamina. For Example - Mango
Parallel Venation
- It is found in monocot leaves. In this type of venation, all the veins run parallel to each other. Parallel venation is further divided into two types.
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| Venation of Leaf |
Pinnately Parallel venation
- When, there is a prominent midrib in the center and multiple veins are arisen which run perpendicular or parallel to each other.
- This is called Pinnately Parallel venation.eg. Banana.
Palmately parallel venation
- Saveral veins are arisen from the tip of the petiole and they all run parallel to each other and are merged at the apex.
- In grass they converge at the apex and hence it is called convergent.
- In Borassus, all the main veins spread out towards the periphery. Hence it is called divergent.
Phyllotaxy: Arrangement of Leaves on Stem
- The arrangement of leaves on the stem or the branches is known as phyllotaxy.
- The phyllotaxy prevent the gathering of leaves and also avoid overcrowding of leaves so that all the leaves receive the sunlight in great duration for photosynthesis. The four main types of phyllotaxy are
Alternate phyllotaxy -
- In this type the leaves are arranged alternatively on the stem. Examples Polyalthia, China rose, Mustard, Sunflower
Opposite Phyllotaxy:
- In this type of arrangement, two leaves are present at each node and both leaves are located opposite to each other.
- In Guava, The pairs of leaves are present at the successive nodes and are found in the same direction.
- On the other hand, two opposite leaves at the node are located exactly above those at the lower node .
- It is termed as Opposite superposed Whereas In Calotropis, one pair of leaves are placed at right angles to the next upper or lower pair of leaves called the Opposite decussate.
Ternate Phyllotaxy -
- In this type of phyllotaxy, there are three leaves attached at each node. Example - Nerium
Whorled Phyllotaxy -
- When more than three leaves are present in a whorl at each node called whorled phyllotaxy. Examples - . Alstonia.
🎯 NEET MULTIPLE CHOICE QUESTIONS
🔥 100% CHALLENGE
"Questions yahi se aayega... taiyari jeet ki
1. Consider the following statements and select the number of correct statements.
1. Leaf is originated from the node of stem.
2. Axil of leaf bear axillary bud which is transformed into a new branch.
3.Leaf is developed from the activity of shoot apical meristem .
4. Leaves are arranged on branch in acropetal order.
5. Leaves are important vegetative organ for Photosynthesis.
A. Two B. Four
C. Three D. Five
Answer : D Explanation
1. Leaf is originated from the node of stem.
2. Axil of leaf bear axillary bud which is transformed into a new branch.
3.Leaf is developed from the activity of shoot apical meristem .
4. Leaves are arranged on branch in acropetal order.
5. Leaves are important vegetative organ for Photosynthesis.
A. Two B. Four
C. Three D. Five
Answer : D Explanation
2. Which one of the following is not a basic part of leaf.
A. Stipule. B. Leaf base
C. Petiole D. Leaf lamina
Answer : A Explanation
3. Which one of the following pair is not correctly matched.
A. Small leaf life appendages bear by the leaf base : Stipule
B. Leaf is attached with the stem : Petiole
C. Leaf base covered stem partially or completely: Monocot plants
D. Swollen leaf base in legune plants : Pulvinus
Answer : B Explanation
4. Leaf is attached with the stem by the
A. Leaf blade B. Leaf lamina
C. Leaf base D. Petiole
Answer: C Explanation
6. Which one of the following statement is not correct.
A. The petiole hold the leaf blade.
B. Leaf blade is most expanded part of leaf and bear stomata.
C. The petiole is also called leaf lamina.
D. Petiole allow the leaf blade to flutter in wind to make leaf cooling and provide fresh air to leaf surface.
Answer: C Explanation
7. Which one of the following structure is not present in leaf blade or leaf lamina.
A. Stipule B. Vein
C. Veinlets D. Stomata
Answer: C Explanation
8. Consider the following statement and select the correct code
1. Vein provide rigidity for the leaf blade.
2. Vein act as channel for transport of water mineral and food material.
3. The prominent mid vein of leaf is called as called Midrib.
A. 1 and 2 B. 2 and 3
C. 1 , 2 and 3. D. 1 and 3
Answer: C Explanation
9. Which one of the following statement is correct.
A. Simple leaves can be Palmately and Pinnately.
B. In simple leaves, incision does not touch the mid rib.
C. Compound leaves are not divided into leaflets.
D. In Compound leaves, incision does not touch the mid rib.
Answer: B Explanation
10. Which of the following statement is incorrect about the compound leaves.
A. In Compound leaves, Incision touch the midrib and leaves are divided into to various leaflets.
B. In Compound leaves, Incision touches the midrib which represent the rachis.
C. Leaflets are present on common rachis which may represent mid rib called pinnately compound leaf.
D. Leaflets are originated from a common point at tip of petiole called palmately compound leaf.
11. Pinnately compound leaves is present in
A. Silk cotton B. Neem
C. Clover D. Cassava
Answer: B Explanation
12. Palmately compound leaves is present in
A. Silk cotton B. Neem
C. Rose D. All of above
Answer: A Explanation
Statement I : A bud is present in axil of petiole of both simple or compound leaves..
Statement Il : This bud is absent in leaflet of compound leaves.
A. Statement l is true and statement ll is false.
B. Statement l is false and statement ll is true.
C. Both statement I and II is true.
D. Both statement I and II is false.
Answer: C Explanation
14. Venation is arrangement of
A. Leaflets on stem
B. Vein and Veinlets on leaf blade
C. Leaves on originating order.
D. Vein and Veinlets on leaf petiole.
Answer: B
15. Consider the following statement and select the correct code
1. Veinlets form a network on leaf lamina, called as Reticulate venation.
2. Reticulate venation is found in Monocotyledon leaf.
3. Veins are run parallel to each other on leaf lamina , called as Parallel venation.
4.Parallel venation is found in Dicotyledon leaf.
A. 1 and 3 B. 2 and 4
C. 1 and 2 D. 3 and 4
Answer: A
16. The arrangement of leaves on stem or branches is called as
A. Venation B. Phyllotaxy
C.Placentation D. Aestivation
Answer: B
17. Which one of the following is not a type of phyllotaxy.
A. Reticulate B. Alternate
C. Opposite. D. Whorled
Answer: A
18. In alternate phyllotaxy, leaves are arranged on stem in alternate manner as in
A. Mustard
B. China rose
C. Sun flower
D. All of the above
Answer: D
19. Consider the following statement and select the correct code
1. In opposite phyllotaxy, two leaves are present at each node and both leaves are originated at opposite to each other.
2. More than two leaves are present in a whorl at each node in Whorled phyllotaxy.
A. Only 1
B. Only 2
C. Both 1 and 2
D. Neither 1 nor 2
Answer: C
20. Whorled phyllotaxy is present in
A. Alstonia B. Calotropis
C. Guava D. Neem
Answer: A
21. In which of the following pair of plant, opposite phyllotaxy is present.
A. Mustard and calotropis
B. Mustard and Guava
C. China rose and Guava
D. Guava and Calotropis
Answer: A Explanation
22. In the given Diagram, identify the letter X and Y.
X Y
A. Leaf base Axillary bud
B. Axillary bud Leaf base
C. Leaf blade Leaf base
D. Axillary bud. Leaf blade
Answer: A
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