Question

Amitosis is shown by
A. Bacteria
B. Hydra
C. Euglena
D. None of the above

Answer 1

Hint: Amitosis is division of the nucleus without condensation of the chromosomes and dissolving of the nuclear membrane. This occurs with simultaneous cytoplasmic divisions giving rise to two daughters having different genetic composition in terms of ploidy (number of the same chromosome). Nucleus is present only in eukaryotes.

Complete answer:
Bacteria are prokaryotic organisms meaning they do not have a membrane bound nucleus. The genetic material in prokaryotes are naked placed directly in the cytoplasm. Bacteria divide by a method called binary fission. Binary fission involves replication of the single bacterial chromosome succeeded by separation of the replicated DNA into two daughter cells and cytokinesis
Hydras are freshwater cnidarians and belong to the genus Hydrozoan. They are multicellular animals which reproduce either sexually (stressful condition, to increase genetic diversity) or by budding from an existing hydra (resource abundance).
Euglenas are aquatic unicellular protists. Most Euglena species possess chlorophyll and carry out photosynthesis. Euglenas are eukaryotes and divide by a process called amitosis. Features of amitosis are unequal division of genetic materials between the daughter cells. Amitotic division occurs without the formation of spindles.
The process of amitosis was first described by Walther Flemming and other groups (Child et al).
Amitosis is also called fragmentation. Amitosis is different from binary fission in that the resulting daughter cells do not inherit identical copies of genetic material. Moreover, amitosis occurs in cells containing a membrane bound nucleus.

Hence the correct answer is OPTION(C)

Note: Though Euglena divide by amitosis, amitosis is not restricted to single-celled eukaryotes. Recent research suggests that amitosis is seen in mammalian organs such as liver.