Question

In primary succession on rocks, the pioneer species are usually
A) Algae
B) Fungi
C) Lichens
D) Bryophytes

Answer 1

Hint:First let us have an idea about Ecological succession. Over a period of time in an ecological community, the process of changes in the species structure is called as Ecological succession. There are 2 types of succession.
->Primary succession
->Secondary succession

Complete Answer:
Primary succession is an ecological succession in which colonization in the living things occurs on the newly formed rocks for the first time. Example- volcanic eruptions, landslides, oil spills etc.
In secondary succession, due to disturbances in the living things in the area, recolonization occurs. Example- changes in the wildlife, replacement of certain fields by forests etc.
>Algae: They are the large group of aquatic organisms that performs photosynthesis. They live in water and are grown with the help of water solvent nutrients (hydroponically).
>Fungi: They are the eukaryotic organisms both single celled and multi celled. They are mostly found on soil rather than growing in water.
>Lichens: Unlike the other plants, lichens can be grown on rocks easily and hence they are called the pioneer species in primary succession.
>Bryophytes: They are the small non vascular plants that produce spores. They are usually found on soil or on dead and decomposed plants, some on rocks and few are aquatic. They need a stable place for attachment.

Hence the correct answer is option (c)Lichens.

Note:Lichens are easily grown on rocks, even bryophytes can be grown on bare rocks provided they have a moisture or humid atmosphere.