Question

Explain the capture of food by amoeba.

Answer 1

Hint: Amoeba are unicellular organisms that do not have a fixed shape as they have the ability to alter their shape by means of pseudopods. They are found in most types of eukaryotic organisms such as algae, fungi, protozoa and animals.

Complete answer:
Amoeba are known to not possess any cell wall as a result of which they are capable of free movement. The structures by which amoeba move are known as pseudopods which are bulges of the cytoplasm caused by the pushing of the plasma membrane by the actin microfilaments.

Amoebas can either be testate which are enclosed by a hard shell or naked which do not have any covering. Amoeba can regulate osmotic pressure by means of contractile vacuole that expel excess water from the cell in the absence of which water enters into the cell and bursts. Amoebas are known to capture food by means of phagocytosis whereby the pseudopods encircle and engulf the prey.

Some amoeba carry out pinocytosis by which they imbibe dissolved nutrients through the help of vesicles. Amoebas can be either be predatory and consume other organisms or detritivores where they consume dead organic matter. Amoeba do not possess a fixed mouth and thus there is no fixed place or region where phagocytosis or pinocytosis occurs.

Note: Amoebas are responsible for causing diseases in humans such as amoebiasis caused by Entamoeba histolytica, Naegleria fowleri also known as the brain eating amoeba which are fatal for humans, Acanthamoeba known to cause amoebic keratitis as well as encephalitis in humans, etc.