Tag: lichen

Lichens are the symbiotic associations i.e; mutually useful associations between algae and fungi. The algal component is known as phycobiont and the fungal component is known as mycobiont. Algae prepare food for fungi and fungi provide shelter and absorb mineral nutrients and water for its partner.  option C is the answer

• A lichen is a composite organism that emerges from algae living among the filaments (hyphae) of the fungi in a mutually beneficial symbiotic relationship.
• Fungi are Achlorophyllous organisms because they do not perform photosynthesis due to the absence of chlorophyll.
• Hence Lichens are composites consisting of algae and achlorophyllous organisms(fungi).
• So, the correct answer is 'Achlorophyllous organisms'.

• Mycorrhiza is the product formed by the symbiotic association between fungus and roots of higher plants, in which fungi protects the plant from pathogens and increases the surface area by which plants can absorb soil nutrients and water whereas plants provide the shelter and carbohydrates to fungi in which both get benefited.

Lichen can grow on barren rock and are the first living organisms or "pioneers" to colonize places, where no other living things can survive.

Foliose lichen is the most complex lichen. It is a lichen with leafy body parts or thallus and which generally have a cortex on each side of the leafy lichen body part thallus. Crustose lichens are lichens that grow like a crust of paint on their substrate, and especially sqamulose crustose lichens, may not be attached to the substrate at the edges, giving a leafy appearance similar to foliose lichens, but there is no lower cortex on the leafy part. Fruticose lichens are lichens that have a form similar to a tiny leafless, branching shrub that may have the branches flattened, so as to appear leafy, but foliose lichens have a single cortex wrapping around the branches, whereas foliose lichens generally have an upper and a lower cortex. Gelatinous lichens may appear leafy, but lack a cortex or internal structure, having the photobiotic component diffuse throughout the no fruiting part of the lichen body, whereas in foliose lichens the algae are in a layer. In foliose lichens, the layer of tissue containing the photosynthetic component has the algae more diffuse in the fungus than in foliose lichens, where the algal layer is generally very distinct.

In lichens, a relationship occurs in which the fungus lives as a dominant organism and algae like a slave, the relationship is known as helotism. It is a form of symbiosis in which one species is forced to perform tasks for another, for their mutual benefit. Thus, the correct answer is option B.