Biological Classification Test - 35

Certaria is a kind of lichen which lives in close association with green algae. It is a very good source of laxative which makes bowel movement easy and loosen the stools. Most of these species are found at high latitudes, occurring on sand and shrub lands.

Rhizopus is a genus of common saprophytic fungi of plants and specialized parasites on animals. They reproduce by forming asexual and sexual spores. In asexual reproduction, Sporangiospores are produced inside a spherical structure, the sporangium. When sporangium gets burst and spill out spore, they germinate into the young one in favourable condition.
Thus, the correct answer is option A.

A lichen is a composite organism that arises from algae or cyanobacteria (or both) living among filaments of a fungus in a symbiotic relationship. The combined life form has properties that are very different from the properties of its component organisms. The fungus benefits from the symbiotic relation because algae or cyanobacteria produce food by photosynthesis. The algae or cyanobacteria benefit by being protected from the environment by the filaments of the fungus, which also gather moisture and nutrients from the environment, and (usually) provide an anchor to it. Thus, the correct answer is option C.

Fungi have been classified mainly on the basis of their sexual reproduction and reproductive structures. Based on this classification, the fungi are divided into Phycomycetes, Ascomycetes, Basidiomycetes and Deuteromycetes.

According to most widely accepted view, the atmosphere of primitive earth was reducing. Cyanobacteria were the first organism to carry out oxygenic photosynthesis, thus releasing oxygen into the atmosphere. Oxygen is a byproduct of oxygenic photosynthesis during which oxygen is produced by splitting of water.

Foliose lichen is a lichen thallus growth form that has a 2-dimensional, flat, leaf-like lobes and lifts up from the surface. Parmelia is a medium to large foliose lichen with ends of the leaf-like lobes often squarish-tipped.

Characters of living nature of viruses are: Viruses have genetic material (DNA or RNA). They can mutate. They can grow, once inside the host cell. They can be transmitted from one host to another. They are capable of multiplication within a host. They react to heat, radiation and chemicals. They show irritability. They bring about enzymatic changes in vitro. They are able to infect and cause the disease to living beings. The DNA and proteins of viruses are similar in composition and structure to those of higher organisms. Thus, the correct answer is option D.

The contractile vacuole is actually a regulatory organelle which is present in protozoans and helps in regulating water balance by osmoregulation. It was earlier known as the pulsating vacuole. It helps in excreting excess water from the protozoans body outside in the surrounding environment.

The correct answer is C.

Viruses are non-cellular organisms that are characterised by having an inert crystalline structure outside the living cell. Once they infect a cell they take over the machinery of the host cell to replicate themselves, killing the host. Viruses are obligate parasites. A virus is a small infectious agent that replicates only inside the living cells of other organisms. Viruses can infect all types of life forms, from animals and plants to microorganisms including bacteria and archaea. Thus, option A is correct. Mycoplasma, bacteria and Lichens are cellular organisms and not characterised by having an inert crystalline structure outside the living cell. Thus, the correct answer is option A.