Angiosperm: Angiosperms are a type of vascular plant that bears both flowers and fruits. These types of plants also contain ovules enclosed in an ovary. The ovule, once fertilized, develops into seeds, which then mature into fruits. Angiosperms are the most advanced and beneficial group of plants. They can grow in various habitats as trees, herbs, shrubs, and bushes.

Characteristics of Angiosperms

• Angiosperms are heterosporous, i.e., produce two kinds of spores, microspore (pollen grains) and megaspores.

• A single functional megaspore is permanently retained within the nucellus.

• The pollen grains transfer from the anther to stigma and reproduction takes place by pollination. They are responsible for the transfer of genetic information from one flower to the other. The pollen grains are much smaller than the gametophytes or reproductive cells present in the non-flowering plants.

• The sporophytes are diploid.

• The root system is very complex and consists of cortex, xylem, phloem, and epidermis.

• The flowers undergo double and triple fusion which leads to the formation of a diploid zygote and triploid endosperm.

• Angiosperms can survive in a variety of habitats, including marine habitats.

• The process of fertilization is quicker in angiosperms. The seeds are also produced quickly due to the smaller female reproductive parts.

• All angiosperms are comprised of stamens which are the reproductive structures of the flowers. They produce the pollen grains that carry the hereditary information.

• All plants have flowers at some stage in their life. The flowers are the reproductive organs for the plant, providing them with a means of exchanging genetic information.

• The sporophyte is differentiated into stems, roots, and leaves.

• The carpels enclose developing seeds that may turn into a fruit.

• The production of the endosperm is one of the greatest advantages of angiosperms. The endosperm is formed after fertilization and is a source of food for the developing seed and seedling.

• The vascular system has true vessels in the xylem and companion cells in the phloem.

• The stamens (microsporophyll) and the carpels (megasporophyll) are organized into a structure called the flower.

• Each microsporophyll has four microsporangia.

• The ovules are enclosed in the ovary at the base of the megasporophyll.

The most common and diverse species of angiosperms are Orchidaceae that belong to the orchid family followed by the daisy, pea, and grass families.

Classification of Angiosperms

Based on the types of cotyledon present, angiosperms are divided into two classes. They are monocotyledons and dicotyledons. The dicotyledonous angiosperms have two cotyledons in their seeds and the monocotyledonous angiosperms have one cotyledon.

Monocotyledonous Plants

• The seeds have a single cotyledon.

• The leaves are simples and the veins are parallel.

• This group contains adventitious roots.

• Each floral whorl has three members.

• It has closed vascular bundles and large in number.

• For eg., banana, sugarcane etc.

Dicotyledonous Plants

• The seeds of these plants have two cotyledons.

• They contain tap roots, instead of adventitious roots.

• The leaves depict a reticulate venation.

• The flowers are tetramerous or pentamerous and the vascular bundles are organized in rings.

• For eg., grapes, tomatoes, etc.

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By Team Learning Mantras