Question

Thallus is foliose in
A. Lichens
B. Algae
C. Mosses
D. All bryophytes

Answer 1

Hint: Thallus is defined as the body part of the organism which is not involved in the reproduction, that means it is a vegetative part of the body. The structure thallus is found in class fungi where filaments of fungus form the structure thallus.

Complete step by step answer: Now we will study about each option so that we will come to know about the occurrence of thallus is where:
Lichens: The body of lichens consist of hyphae, houses of cortex and medulla which forms the main body part of lichen called thallus. It is characterized by the presence of the upper and lower cortex with a flattened leafy part called thalli.
Algae: They are the unicellular or multicellular photosynthetic organisms, lacking well defined structure that means the body of algae do not have roots, shoots or leaves. Algae are found in the area where there is presence of moisture and the mode of reproduction can be asexual and sexual as well. There is a characteristic of algae which is shared by fungi also that is absence of vascular tissue.
Mosses: They are the non-vascular plants which form spores as a mode of reproduction and their bodies do not have well defined structures, they lack woody parts, flowers and roots. Majority of mosses are found in moist and shaded places and some of them are found in environments with dry conditions.
All bryophytes: They are the group of non-vascular land plants consisting of three divisions: the mosses, hornworts and liverworts. They are limited in size characteristically and prefer mostly moist habitats and can even prevail in drier environments.
Thus the correct option is A, since it contains the vegetative body part known as thallus.

Note: lichen is categorized into three types because of their characters:
-Foliose: which is leaf like
-Fruticose: tube structures which are free standing
-Crustose: which is crust like