Question

_______ and ________ are unicellular algae, rich in proteins that are used as food supplements even by space travellers.
A. Chlorella, Spirulina
B. Gelidium, Gracilaria
C. Porphyra, Spirogyra
D. Laminaria, Spirogyra

Answer 1

Hint:-Green algae are used as food supplements which are unicellular organisms. Chlorella and spirulina are microalgae and rich in protein and have sufficient amounts of other nutrients such as vitamins, fatty acids and pigments.

Complete step-by-step solution:-
Chlorella spp. are spherical members of Chlorophyta phylum used as food supplements in recent times. Chlorella is a green algae containing 51%-58% protein. Spirulina is a filamentous blue green also enriched in vitamin B and has a sufficient amount of protein. Chlorella was derived from Greek word chloros and from Latin word ella which means green and small. Spirulina defines its spiral shape and is commonly called cyanobacteria which is a blue green algae.
Gelidium and Gracilaria both are used in the production of AGAR gel. Lamineria is treated as a raw food and eaten as lavender in the south wales. Porphyra and spirogyra are eaten as sushi which is a Japanese dish formed by rapping algae in rice and fishes. They are not rich in protein. Due to less protein content these algae are not used by space travelers. As chlorella and spirulina are rich in protein they are used as food supplements by space travelers. So the correct option is A.

Note:-
  Chlorella vulgaris produces oxygen and also produces a nutritional biomass which can be eaten by astronauts in space. This nutritional biomass is edible and reduces the transport of food in space which is an advantage of green algae. The scientists in space use them as portable oxygen generators and food sources.