Question

Classification of algae - recent trends in classifications

Answer 1

Answer:

Presence of pigments which imparts traditional color on algae is the main basis for the classification of algae.

Chlorophyceae

• Chlorophyll a and chlorophyll b

• Green

Phaeophyceae

• chlorophyll a, chlorophyll c, fuxoxanthin

• Brown

Rhodophyceae

chlorophyll a and chlorophyll d, phycoerythrin

Red

Now, algae are classified on different criteria such as:

Flagellation

Storage products

Cellular organization

Constitution of cell walls

Answer 2

Explanation:

These divisions are based on the following factors:

(a) Major photosynthetic pigments present

(b) Form of stored food

(c) Cell wall composition

(d) Number of flagella and position of insertion Class I – Chlorophyceae

Common name – Green algae

Major pigments – Chlorophylls a and b Stored food – Starch

Cell wall composition – Cellulose

Flagella number and position – 28; equal and apical Class II – Phaeophyceae

Common name– Brown algae

Major pigments – Chlorophylls a and c, and fucoxanthin Stored food – Mannitol and laminarin

Cell wall composition – Cellulose and algin

Flagella number and position – 2; unequal and lateral Class III – Rhodophyceae

Common name – Red algae

Major pigments – Chlorophylls a and b, and phycoerythrin Stored food – Floridean starch

Cell wall – Cellulose, pectin, and polysulphate esters Flagella number – Absent