Question

Which of these may live as a space – parasite in Anthoceros?
A. Ulothrix
B. Spirogyra
C. Nostoc
D. None of the above

Answer 1

Hint: Anthoceros is a genus, it is related to the family Anthocerotaceae. This is found all over the world. Anthoceron means flower horn or horn-shaped sporophytes. The sporophytes of Anthoceros are larger and complex, which differentiated into a foot, a constriction like an intermediate zone, and a capsule.

Complete answer:
> Option A:
Ulothrix is non-branching filamentous green algae, which is generally found in fresh and marine water. This alga does not represent any kind of relationship with other organisms.

> Option C:
Nostoc is cyanobacteria (blue-green algae), which occurs in various environments, this alga forms colonies composed of filaments of moniliform cells in the gelatinous sheet, Nostoc shows a symbiotic relationship with many plants and herbs. Eg: Cycad and Anthoceros.

> Option B:
Spirogyra is filamentous charophyte green algae, named for the helical or spiral arrangement of chloroplasts, it is also known as water silk and blanket. And this alga does not show any relationship with other organisms.

Blue-green algae like Nostoc and Anabaena are found as endophytes in liverworts like Anthoceros plants. These algae are also known as space parasites because of their habits where they stay inside the plants.

Hence, the correct answer is option (C).

Note: Endophytes are those organisms that live between living plant cells. The relationship that they establish with plants sometimes may be symbiotic or parasitic too. Mostly, Fungi and bacteria come into these categories.