Question

Which of the following animals is a parasite?

• A. Entamoeba histolytica
• B. Musca domestica
• C. Amoeba proteus
• D. Hydra oligactis

Answer 1

Answer: (A)

Entamoeba histolytica

• Entamoeba histolytica is an anaerobic parasitic protozoan, part of the genus Entamoeba. Predominantly infecting humans and other primates, E. histolytica is estimated to infect about 50 million people worldwide. Previously, it was thought that 10% of the world population was infected, but these figures predate the recognition that at least 90% of these infections were due to a second species, E. dispar. Mammals such as dogs and cats can become infected transiently, but are not thought to contribute significantly to transmission.
• The housefly, Musca domestica, is a fly of the suborder Cyclorrhapha. It is the most common of all domestic flies, accounting for about 91% of all flies in human habitations.
• Amoeba proteus, is an Amoeba closely related to the giant amoebae and a species commonly bought at science supply stores.
• Hydra oligactis, also known as the brown Hydra, is a species of hydra found widely dispersed in the northern temperate zone. It is a common organism found in still waters from early Spring to late Autumn.