Question

Which of the following is parasitic algae?
a. Cephaleuros
b. Harveyella
c. Both A and B
d. None of the above

Answer 1

Hint: Algae contain near about 18,000 genera with 29,000 species. All of them have a thallus organization and they lack a differentiation of the body into true roots stems and leaves.

Complete answer:
> Chlorophyll pigment is found in all members of algae. However in many, green color is masked by other pigments. They are classified into three types on the basis of different types of pigments found in them:
- Green algae- They have chlorophyll a and chlorophyll b pigment.
- Red algae- They have phycoerythrin and phycocyanin pigments along with chlorophyll and carotenoid.
- Brown algae- They have chlorophyll a and chlorophyll c along with the brown fucoxanthin pigment.

> Some red algae like Harveyella is found heterotrophically as parasites on other autotrophic, photosynthesizing red algae.
> Cephaleuros is a green alga i.e. parasitic in nature and causes red rust of tea. It is a genus comprising approximately 14 species. Their average size is around 10 mm. They form dichotomous branches and this algae is parasitic on some economically important plants like coffee, tea, mango, guava, etc. Some members of this genera also grow with fungus to form a lichen that does not damage the plants.

So both Cephaleuros and Harveyella are examples of parasitic algae.
Hence, the correct answer is option (C).

Note: Algae show great variation in their habitats like they are found in moist places, on tree trunks, in still and running waters, on flower pots and a number of them are marine. Few algae are marine i.e. found in sea water. Most of the brown and red algae are marines. Some siphonaceous algae are also found in the sea.