Question

Usnic acid is an antibiotic obtained from which of the following:

• A. Bacteria
• B. Algae
• C. Fungi
• D. Lichen

Answer 1

The correct option is D

Lichen

The correct option is D.

Explanation of the correct option:

1. The lichens are the symbiotic institutions of fungi and algae.
2. These are located developing over barks of trees, stone surfaces, rotting materials, etc. they live connected to the substratum.
3. Usnic acid is a yellow crystalline acidic compound having molecular method C₁₈H₁₆O₇.
4. German scientist W.Knop isolated it.
5. The usnic acid is synthesized via way of means of numerous lichen species specifically Usnea, Cladonia, Alectoria, etc.
6. It is thought that usnic acid in lichens is used to guard them against the dangerous outcomes of sunlight.
7. It is a secondary metabolite of lichens. the sour flavor of usnic acid protects the lichens from grazing animals.

Explanation of the incorrect options:

Option A:

1. Bacteria are pathogenic organisms.
2. However, some of them, like Lactobacillus sp. are good for gut health.
3. They are not the source of usnic acid.

Option B:

1. Algae are photosynthetic, microscopic plants.
2. They form the photosynthetic unit of lichens.
3. However, they are not responsible for usnic acid synthesis.

Option C:

1. Fungi are heterotrophic, eukaryotic organisms that form another component of the lichens that provide shelter to the algae.
2. Usually, many fungi species are recognized that have antibiotic properties.
3. For example, penicillin is acquired from a fungus that kills many bacterial species. However, they are not responsible for usnic acid synthesis.

Final answer: Usnic acid is an antibiotic obtained from lichens.