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.

• 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.

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.

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.

Seed coat consists of the testa, the outermost hard brownish covering. It protects the delicate inner parts of the seed from injury and attack of bacteria, fungi and insects. Tegmen is a thin inner layer lying next to the testa. Hilum is a distinct whitish oval scar on the concave side of the seed. It represents the spot where the ovule (now the seed) was attached to the ovary wall through placenta.

• Spines in cactus are due to modifications of leaves.
• Cactuses are mainly found in arid regions.
• So, in order to reduce transpiration of water leaves modify themselves into spines.

Hibiscus comprises five petals that remain free but create an overlapping arrangement at the margin of the appendages. This is a type of twisted aestivation. Aestivation is the arrangement of the corolla (petals) and calyx (sepals) in relation to each other in a flower bud. 

• 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.

If the margins of sepals or petals overlap one another but not in any particular direction as in Cassia and gulmohur, the aestivation is called imbricate.

• A mustard flower is an example of an actinomorphic flower.
• A flower is said to be actinomorphic if it possesses radial symmetry and zygomorphic if it possesses bilateral symmetry.

• In racemose inflorescence, the youngest flower remains at the top of floral axis and indefinite number of flowers are formed.
• In cymose inflorescence, the floral main axis is limited however the axilary branches continue to grow throughout the life.

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.

• Basal enclosed part of carpel is called ovary.
• Ovules are attached to cushion like structure called Placenta.
• Stigma is the part of the carpel that receives pollen grain.
• Arrangement of ovules within the ovary is called Placentation.

• 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.

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.