Test: The Leaf (NCERT) - NEET MCQ

This is the correct option as this statement is false. Veins provide rigidity to the leaf blade and act as channels for transporting water, minerals and food materials.
Topic in NCERT: THE LEAF
Line in NCERT: "The leaf develops at the node and bears a bud in its axil." "They are the most important vegetative organs for photosynthesis." "Veins provide rigidity to the leaf blade and act as channels of transport for water, minerals and food materials." while In some leguminous plants the leafbase may become swollen, which is called the pulvinus.

• The arrangement of leaves in the plant is called phyllotaxy.
• In alternate phyllotaxy, a single leaf is present at each node.
• This kind of phyllotaxy is seen in China rose.
• In whorled phyllotaxy, multiple leaves are present at each node.

Topic in NCERT: Phyllotaxy
Line in NCERT: "In alternate type of phyllotaxy, a single leaf arises at each node in alternate manner, as in china rose, mustard and sun flower plants.In opposite type, a pair of leaves arise at each node and lie opposite to each other as in Calotropis and guava plants. If more than two leaves arise at a node and form a whorl, it is called whorled, as in Alstonia."

In many legumes leaf base is swollen, it is known as pulvinus. It is responsible for sleep and shock movements of certain leaves, e.g., Mimosa pudica.

Topic in NCERT: The section name from which the line is given is "THE LEAF".

Line in NCERT: "In some leguminous plants the leaf base may become swollen, which is called the pulvinus."

In opposite phyllotaxy two leaves are borne on the opposite side of a single node. Opposite phyllotaxy is of two types: (i) Opposite and superposed e.g., Syzygium, (ii) Opposite and decussate, e.g., Calotropis, Zinnia.

Topic in NCERT: Phyllotaxy

Line in NCERT: "In opposite type, a pair of leaves arise at each node and lie opposite to each other as in Calotropis and guava plants."

• In reticulate venation, veins are arranged haphazardly.
• However in parallel venation, veins are arranged in a parallel manner.
• Both the kinds can be further classified into palmate and pinnate.
• In pinnate venation, only one strong mid-rib is present and in palmate venation more than one strong rib is present.
• Rice is an example of convergent palmate parallel venation.

Topic in NCERT: Venation

Line in NCERT: "When the veins run parallel to each other within a lamina, the venation is termed as parallel."

In alternate (or spiral) phyllotaxy, only one leaf is borne on a node and the leaves of the adjacent nodes roughly lie towards the opposite sides (e.g., Hibiscus). In opposite phyllotaxy, two leaves are borne on the opposite sides of a single node, e.g., guava in whorled or verticillate phyllotaxy, three (e.g., Nerium) or more than three (e.g., Alstonia) leaves develop from a single node.

Topic in NCERT: Phyllotaxy

Line in NCERT: "Phyllotaxy is the pattern of arrangement of leaves on the stem or branch. This is usually of three types alternate, opposite and whorled."

Alternate

• In this case, a single leaf arises at each node.
• The leaves are arranged in an alternate manner.
• It is observed in china rose, mustard, and sunflower.

Opposite

• In this case, a pair of leaves are arranged on either side of the node.
• The leaves lie opposite each other.
• It is observed in Calotropis. 

Whorled

• ​If more than one leaf arises from a node and forms a whorl, the kind of phyllotaxy is called whorled phyllotaxy,
• It is observed in Alstonia.

So, the correct answer is option 2, Alstonia.
Topic in NCERT: Phyllotaxy
Line in NCERT: "If more than two leaves arise at a node and form a whorl, it is called whorled, as in Alstonia."

2 types of leaves are present-simple and compound.

• the leaf which is undivided into smaller units is called simple leaf
• In compound leaves,the leaf is divided into smaller leaflets.
• In palmately compound leaves, the leaflets originate from a single point at the base end of the petiole.

Topic in NCERT: Types of Leaves

Line in NCERT: "In palmately compound leaves, the leaflets are attached at a common point, i.e., at the tip of petiole, as in silk cotton."