Introduction of Monocot and Dicot Plant Anatomy
In the world of Botany or Flora, seeds are the fundamental part of reproduction in plants. But the Gymnosperms have no fruits or flowers. So, their seeds are open-eyed. On the other hand, Angiosperms have well-matured ovules. Angiosperms are considered one of the most diversified sub-group of the Plant Kingdom as it comprises about 2,00,000 species. In the plants of this subgroup, seeds are formed inside the fruits, and also a seed coat is present in the seeds. On the basis of the numbers of cotyledon, plants of the sub-group angiosperm are divided into two categories: monocot plants and Dicot plants. Angiosperms are plants that produce flowers and consist of seeds in the fruits.
The Definition of Monocot and Dicot Root
Monocot Plant refers to those plants which have only one cotyledon in the seed. It is also called a monocotyledon plant. Example garlic and onion.
Dicot Plant refers to those plants which have cotyledon in their seed. It is also called dicotyledon plants. Example Radish and Mustard
Monocot Leaf
Monocot Plant leaves have a parallel venation system.
Bulliform cells are found in the monocot leaves which are developed from the veins and adaxial epidermal cells.
In the mesophyll, no differentiation is found between the palisade and spongy parenchyma.
The curling of leaves for the least loss of water is due to the bulliform cells which are large, void cells.
Dicot Leaf
Dicot Plants leaves have a reticulate venation system.
The epidermis, mesophyll, and vascular system are found in the lamina.
In leaves, photosynthesis is performed by the chlorophyll which is present in the mesophyll.
Bundle sheath surrounds the vascular bundles which form midrib and veins.
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Monocots Roots
They consist of an adventitious root system.
In monocot, the number of xylems found is six or more.
Pith found in monocots is large and conspicuous.
Dicots Roots
In Dicot, the number of phloem or xylem found is two or four.
The central pith in the dicot plant is inconspicuous.
Cortex has an inner layer which is called endodermis. This layer is packed tightly by the barrel shaped-cells.
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Difference Between Monocot Leaf and Dicot Leaf
Difference between Monocot Root and Dicot Root
Similarities Between Monocot and Dicot Root
Both have Xylem.
Cortex is present in both.
Both roots absorb water and minerals.
Vascular bundle presents in both the root.
Anatomy of Dicotyledonous Roots
In these plants, root leaves, flowers, fruits and seeds are fully developed.
The epidermal cells project out and appear as their root hair.
The epidermis consists of a multi-layered cortex that is freely made of the parenchyma cells.
Cortex has an inner layer which is called endodermis. This layer is packed tightly by the barrel shaped-cells.
A layer of parenchymatous cells is used to differentiate xylem and phloem which is called conjunctive tissue.
Anatomy of Monocot Stem
These stems are usually hollow and do not have secondary growth.
Vascular bundles are numerous. They are scattered, attached, closed, and are surrounded by the tissue.
Phloem parenchyma is absent in Monocot Stem.
Anatomy of Dicot Stem
The dicotyledonous stem is usually solid. The transverse section of a young dicotyledonous stem consists of the following parts:
The epidermis is a protective layer that is covered with a thin layer of cuticle.
Cortex is multi-layered cells that are situated between the epidermis and pericycle.
The outer layer, hypodermis, the cortical layers, and the inner layer endodermis, together build up the three subzones of the cortex
Anatomy of Monocot and Dicot Plants
The difference between monocot and dicot plants: Plants are of two types and those are monocot plants and dicot plants. Each has a different arrangement of internal tissue and organisation in its stems and roots.
Difference Between Monocot and Dicot Plants on the Basis of Roots:
The outermost layer of roots in both monocot and dicot plants is the epidermis, which forms the root hair. The middle layer is the cortex and consists of several layers of thin-walled parenchyma cells. The innermost layer is endodermis. The vascular tissue xylem in monocot root is more than six that is Polyarch, while in dicot root the xylem bundles are Tetrarch.
In the cross-section of monocot root, the metaxylem vessels appear circular, while in dicot root the vessels appear polygonal. The cells that lie between xylem and phloem bundles are known as conjunctive tissues. These cells are sclerenchymatous in monocot root while parenchymatous in dicot root. The Pith is large and fully developed at the centre in monocot roads while in Dicot roots it is small or inconspicuous.
Difference Between Monocot and Dicot Plants on the Basis of Stem:
The outermost layer of the stem of both monocot and dicot plants is the epidermis. The middle layer which is present in both the monocot and Dicot stem is the cortex. The hypodermal regions of the cortex in the Dicot stem consist of collenchyma cells while in monocot stems sclerenchyma cells are present. The vascular bundles are arranged in the form of rings in the Dicot stem whereas in monocot stem vascular bundles are in scattered form. The pith is large in dicot stems while it is absent in monocot stems. The vascular bundles of dicot stems, because of the presence of the cambium, are the Open type. While in monocot stem the bundles are the closed type. The ground tissue of a dicot stem is differentiated into Stellar and extra stellar tissues whereas in a monocot stem the ground tissue is not differentiated.
Anatomy of Dicotyledonous Plants
Roots - The roots of these plants have a tap root system. These plants have two layers of roots. The outermost layer is the epidermis which usually forms the root hairs sometimes and the inner layer is called the endodermis. The epidermis layer consists of cells that are loosely packed whereas the endodermis has tightly packed cells.
Stems - The stems of these plants are usually solid in nature and it has cambium present in it. The number of xylem and phloem which are present in these plants varies from two to four and these are being distinguished by the layer of parenchymatous cells which are known as conjunctive tissue. The pericycle is also present in it. The Vascular bundles which are present in the stem are fewer and are arranged in the circle. Phloem parenchyma and phloem fibers are also present in these plants.
Leaves - The leaves which are present in these plants have a stall and have reticulate or net venation. The mesophyll which contains the chloroplasts is made up of spongy and parenchymatous cells and is present in these plants.
Flower and Seeds - The flowers which are present in these plants are usually pentamerous which means the floral parts which are present are in numbers of five. The seeds germination in the flowers of these plants are either hypogeal or epigeal. In pollen grains that are present in it have three furrows or pores and they have three furrows or pores.
Anatomy of Monocotyledonous Plants
Roots - The roots of these plants have an adventitious root system and the pith of it is large and conspicuous. The number of xylems that are present in these plants is 6 or more. Due to the absence of cambium, secondary growth is absent in these plants.
Stems - The stem of these plants are usually hollow and cambium is not present in these plants, hence there is no secondary growth in stems. The vascular bundles which are in the stem are scattered and numerous. Phloem parenchyma, pericycle, and pith are absent in these plants. Vascular bundles which are present in these plants are being surrounded by a sclerenchymatous bundle sheath
Leaves - The leaves of monocotyledonous plants are sessile which means these are directly attached to their base without its stalk. The leaves of these plants have venation that is parallel. The Mesophyll present in it is not differentiated into spongy and palisade cells.
- Flower Seeds - The seed germination in these plants is hypogeal and has a single cotyledon. The flowers are incomplete in these plants and the floral parts are present in the number of threes. The pollen grains of these flowers have a single pore or furrow.
FAQs on Monocot and Dicot Plant Anatomy
1. What is the difference between Monocot and Dicots Root on the basis of their key features?
Pericycle in monocot roots produces only the lateral roots while the pericycle gives lateral roots, cork cambium, and the part of the vascular cambium in dicot roots.
The pith of the monocot root contains a large number of starch grains. But in the dicot root, Pith is completely shattered.
In the Monocot Root, Xylem and phloem are numerous in number. Whereas in Dicot Root, Xylem and phloem are limited in numbers.
In monocot roots, passage cells are absent in the endodermis. On the other hand, these cells are present in the endodermis of dicot roots.
2. What is a Dicotyledonous seed? State the key structure of a Dicotyledonous seed.
Dicotyledon is a classification of flowering plants where the seed empowers two embryonic leaves or cotyledons.
Dicotyledons have a bloated appearance due to their food reserve, which is used to bring up the developing seedling. The embryo axis has two ends, the plumule, and radicle. It is surrounded by a protective cover called the seed coat. The seed coat is built up by an outer layer called testa and an inner layer called the tegmen. A structure called hilum is found which adjoins the seed to the fruit.
