Question

Lichens are association between: ____.

• A. Bacteria + algae
• B. Algae + fungi
• C. Virus + bacteria
• D. Fungi + moss

Hint:

Remember the labor division: Algae cooks the food (Phycobiont = Chef) and Fungi builds the house (Mycobiont = Architect/Landlord).

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
A symbiotic relationship is an obligate mutual interaction where two distinct biological species live in close physical contact for shared survival benefit.

Step 2: Detailed Explanation:
Lichens are composite organisms showing a permanent symbiotic association between:
• Algal Component (Phycobiont): This component is autotrophic. It synthesizes food through photosynthesis for both partners. (It can also be a cyanobacterium).
• Fungal Component (Mycobiont): This component is heterotrophic. It forms the structural body shelter, absorbs mineral nutrients, and anchors water from the substrate for the partner. The integration is so intimate that they look like a single individual plant in nature.

Step 3: Final Answer:
Lichens are an association between algae and fungi.

Answer 2

The question asks which two organisms combine to form a lichen, so each option is checked against what each partner in a lichen actually contributes.

1. Bacteria + algae: While some lichens do involve cyanobacteria instead of green algae, the defining, universally present partner alongside the photosynthetic component is a fungus, not a generic bacterium, so this pairing misses the structural half of the relationship.
2. Algae + fungi: The alga (or in some cases a cyanobacterium) photosynthesises and supplies food for both partners, while the fungus forms the body of the lichen, anchoring it to a surface, retaining water, and absorbing minerals. Together, this is exactly what makes up a lichen.
3. Virus + bacteria: Neither of these two organisms photosynthesises or forms the layered, root-like body seen in a lichen, so this pairing does not match lichen biology at all.
4. Fungi + moss: A moss is a fully formed, independent plant with its own leafy gametophyte, not a photosynthetic partner living inside a shared fungal body the way an alga does in a lichen.

A lichen's two essential partners are always a photosynthetic organism, most commonly an alga, and a fungus that provides the physical structure.

Therefore, the correct answer is Algae + fungi.