Question

Write explanatory notes on (i) bacterial reproduction (ii) mycoplasma (iii) archaebacteria.

Answer 1

Hint: Bacteria reproduce by sexual, asexual and vegetative methods. Mycoplasma are the type of bacteria that lack the cell wall around their cell membrane, which is otherwise present in other bacteria. Archaebacteria is a single celled prokaryotic organism.

Complete answer:
(i) Bacterial reproduction: Bacterial reproduction occurs by sexual, asexual and vegetative mode of reproduction. Budding, binary fission and fragmentation occurs in vegetative methods of reproduction as bud is developed in budding from one end of the cell. Asexual reproduction includes endospore formation, zoo spore and conidia formation. Sexual reproduction includes transformation, conjugation and transduction which help in genetic recombination.
(ii) Mycoplasma are the type of bacteria which lack the cell wall but cell membrane is present. Due to absence of cell wall they are resistant to many antibiotics which includes penicillin that attack on cell wall synthesis. These bacteria can be saprotrophic or parasitic. Mycoplasma are the smallest bacteria cells known and can survive without the oxygen and are of various shapes.
(iii) Archaebacteria are the single celled prokaryotic organisms which are of different groups like methanogens, halophiles and thermophiles. Archaebacteria have special unique properties which separate them from other two domains of life which are bacteria and eukaryotes. Archaebacteria are generally the same in size and shape.

Note: Archaebacteria are not included in bacteria, they were included in bacteria domain previously from where they get this name but after analyzing their special properties they were excluded from the bacteria group and kept separate from bacteria and eukaryotes.