Biological Classification Test - 32

• 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'.

The Opalina is a small group of protists, assigned to the family Opalinidae. Their name is derived from the opalescent appearance of these microscopic organisms when illuminated with full sunlight. Most Opalina live as endocommensals (dwelling within the body of its host) in the large intestine and cloaca of frogs and toads. Thus, the correct answer is option B.

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. 

Lichens of the genus Sticta have a characteristic feature of having holes or pit that are found on the lower surface of the cortex and called as cyphellae. They look like a cup or irregular depressions on the lower surface. They are formed by loosely arranged hyphae and opens into the medulla which helps in aeration. Thus, the correct answer is option A.

• Diplanetism is a phenomenon having two mobile stages with a pause between them
• Saprolegnia release a zoospore that forms a cyst right away. This will germinate at some later time to release its secondary zoospore. 
• Hence Diplanetism is exhibited by Saprolegnia.
• So, the correct answer is 'Saprolegnia'.

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

Lichen is a symbiotic association of fungi and algae. It consists fungal partner, or mycobiont, and one or more photosynthetic partners or photobionts, which can be either green algae or cyanobacteria. Algal photobionts are called as phycobionts.

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.

Cladonia rangiferina, also known as reindeer moss, belonging to the Cladoniaceae family is a light-coloured, fruticose lichen. It grows in both hot and cold climates in well-drained, open environments. It is found primarily in areas of alpine tundra, it is extremely cold-hardy. Other common names include reindeer moss and caribou moss, but these names may be misleading since it is not a moss. Thus, the correct answer is option D.

Nummulite specimens from the eocene limestones of the Egyptian pyramids often exceed 5 cm in diameter. Nummulites were abundant during the Paleogene and Neogene periods (65.5 million to 2.6 million years ago). Nummulites were particularly prominent during the Eocene Epoch (55.8 million to 33.9 million years ago), and limestone of this age that occurs in the Sahara is called nummulite limestone in reference to the great abundance of its contained fossil nummulites.