Question

Hypodermis of monocotyledonous stem is?
A. Parenchymatous
B. Chlorenchymatous
C. Collenchymatous
D. Sclerenchymatous

Answer 1

Hint: Tissue consist of long, narrow cells with thick and lignified cell walls. It is having little or no protoplast that makes the tissue hard and rigid. It is responsible for providing mechanical support to the young stem.

Complete Answer:
- Anatomically a plant stem is having various parts like epidermis, xylem, phloem, pith, cortex etc.
- One of the parts is known as Hypodermis which is the outermost layer in the cortex of plants that is lying immediately below the epidermis.
- It is present in the stem of both monocots and dicots. It can be either collenchymatous or sclerenchymatous.
- In monocot stem, Hypodermis is sclerenchymatous in nature and is responsible for providing mechanical support to the young stem. Hypodermis is also known as the exodermis.

The correct option is D i.e. Sclerenchymatous.

Additional information: In the monocot stem have some salient features. These are:
- Vascular bundles are scattered in nature and each bundle is surrounded by sclerenchymatous bundle sheath.
- Endodermis, pericycle, pith and cortex are not differentiated.
- The vascular bundles are collateral and closed.
- The phloem parenchyma is absent.
- Epidermal hairs are absent.

Note: Sclerenchyma is having lignin and high cellulose content about 60-80% due to which it appears as hard and rigid. Due to their hard and rigid appearance, it is considered as dead.
- Sclerenchyma is also present in the fruit walls of nuts, pulp of fruits like sapota,guava and pear.
- The Hypodermis of dicot stem have collenchymatous tissue. The tissue is having thickened corners due to the deposition of cellulose, hemicellulose and pectin.