Biological Classification Test - 10

The genus Ustilago includes the group of fungi producing lack, sooty powder mass of spores on the host pl(mt peris imparting them a burnt appearance, hence, the name, the black dusty masses of spores produced by these fungi resemble soot or smut, so these are also known as smut fungi.

Sexual recombination in bacteria takes place by transduction, transformation and conjugation. Transduction is a process in which a bacteriophage (virus) takes part in genetic recombination in bacteria. Translation is synthesis of protein from m-RNA. In conjugation whole or a part of bacterial chromosome transfered into the recepient cell through a conjugation tube that joins the two cells. The process in which a part of foeign DNA may integrate in the chromosome of recepient cell by a process of recombination is called transformation.

In bacteria, respiration occurs in cytoplasmic membrane because bacteria is a prokaryotic cell (true nucleus and membrane bounded organalle are absent).

Mushroom comes under family Agaricaceae of sub division basidiomycotina. The somatic mycelium of mushroom, also known as rhizomorphs. It is present under the soil and serves the function of vegetative reproduction. The aerial part of mushroom constitutes its fruiting body, the basidiocarp, and is made up of fleshy stalk with umbrella like head at the top. The basidiocarp forms the edible part of mushroom.

Euglena is called as 'connecting link' between plant and animal, because it has characteristics of both plant and animals. Like plants, they have chloroplasts with the help of which they perform photosynthesis. Like animals, they lack cell walls and in absence of sunlight, they possess a structure called as flagellum, which is used to obtain food, therefore performing heterortrophic nutrition. 

Members of the fungal class Myxomycetes are called slime moulds. Their life cycle begins as a diploid amoeboid cell which divides by mitosis but without undergoing cytokinesis, resulting in the formation of a coenocyte consisting of many nuclei and behaves like a feeding plasmodium. Under scarce and dry conditions, the coenocyte breaks into several plasmodia, each of which develops into a fruiting body. The fruiting body forms haploid spores, each of which develops into a flagellated gamete.

Flagella of prokaryotic and eukaryotic cells differ in micro-tubular organization and type of movement. In eukaryotes the arrangement is (9+2) and specialized while in prokaryotes arrangement is (9+0) and is simple.

AIDS (acquired immunodeficiency syndrome) is caused by the HIV virus.

HIV (Human immunodeficiency virus)belongs to the special class of viruses called retrovirus.with in this class HIV is placed in a subgroup called lentivirus.

HIV consists of a viral envelope.with in the viral envelope 2 identical copies of single-stranded RNA are a present and reverse transcriptase enzyme. Hence HIV has a protein coat and a genetic material which is ss RNA.

Mycoplasma is the smallest organism that does not possess a cell wall. It is a prokaryote organism, composed of single cell and are non-motile. The cell contains the cell membrane, proteins, DNA and ribosomes. The absence of a cell wall renders the organism insensitive to most of the antibiotics.

Bacteria are unicellular prokaryotes and have a well defined rigid cell wall that provides them resistance to drugs/antibiotics/desiccation. The cell walls of bacteria are composed of a macromolecule peptidoglycan, which is a repeating framework of long glycan chains having alternate N-acetyl glucosamine and N-acetyl muramic acid; these glycan chains are cross-linked by short peptide fragments to provide a strong but flexible support framework. Likewise, plants are characterized by presence of cellulosic cell wall outside their cell membrane, which makes option B correct.