Define Thallophyta.

Hint: The living organism is classified into two kingdoms – 1. Kingdom Plantae and 2. Kingdom Animalia. The plant kingdom consists of bacteria, fungi, algae, photosynthetic plants, and non – photosynthetic plants, and the Animal kingdom consists of unicellular protozoa and multicellular metazoans. Among them, thallophyta comes under the subkingdom of kingdom Plantae.

Complete step by step answer:
Thallophyta is defined as a group of non-motile and lower plants. It includes fungi, molds, algae, lichens, etc. In modern taxonomy, the thallophyta is considered as a division under the sub-kingdom cryptogame.
Some important characteristics of Thallophyta are listed below:
-Thallophyta is a non-motile plant.
-The first ten phyla are referred to as Thallophyta.
-They are usually present in wet regions like the sea, ponds, and some other water residues because they lack true roots.
-They do not produce seeds.
-The mode of food synthesis in a thallophyta is both autotrophic and heterotrophic.
-They also lack vascular tissue for the supply of water and minerals.
-Most thallophyta organisms are green. So, they have chlorophyll pigmented.
-Division Thallophyta has two subdivisions: Algae and fungi.
-Algae: Algae is the aquatic large group of polyphyletic organisms, they conduct photosynthesis.
-Fungi: fungus is the photosynthetic eukaryotic organism.

Note:
Thallophyta is only a division under the sub-kingdom. It is a large group of primitive organisms.
Thallophytes do not have xylem and phloem tissues for the transport of food and water.
The subdivisions of thallophyta are also named as Myxothallophyta and Euthallohyta wherein the former subdivision includes myxomycetes while the later subdivision includes bacteria, fungi, lichens, and algae.