Amoeba

Nov 08, 2022, 16:45 IST

An amoeba is a unicellular organism that can change its shape. They are usually found in bodies of water such as lakes, ponds, and slow-flowing rivers. Sometimes these single-celled organisms can get into the human body and cause various illnesses. One of the first reports referring to amoeba dates can be traced back to the 18th century. A German naturalist named August Johann Rösel von Rosenhof discovered the specimen in 1755 and made detailed illustrations of it.

Structure of Amoeba

Typically, most amoebae are characterized by the following characteristics:

• Movement occurs through pseudopodia, where the cytoplasm pushes the plasma membrane outwards or inwards, forming blunt finger-like projections.
• In one particular case, there may be several pseudopodia. Therefore its shape changes rapidly.
• The structure of amoeba primarily includes three parts – cytoplasm, plasma membrane, and nucleus.
• Cytoplasm can be divided into two layers – outer ectoplasm and inner endoplasm.
• The plasma membrane is a thin, double-layered membrane composed of protein and lipid molecules.
• Amoeba also contains the other cell organelles such as mitochondria, contractile vacuole, Golgi apparatus, and fat globules.
• An amoeba consumes food either through the process of pinocytosis or phagocytosis.
• The process of reproduction is through asexual means such as binary fission.
• The lifespan of a typical amoeba is two days, but because it undergoes binary fission, the resulting daughter cells are the same as its parent cell, so technically, amoeba can be described as immortal.
• When living conditions are not ideal, the amoeba can essentially turn into a protective ball called a microbial cyst. When living conditions improve, it can revert back to the trophozoite stage, where it can start feeding again.

Classification of Amoeba

Traditionally, amoebae are grouped under the kingdom Protista because they are not classified as a plant, animal, or fungus. However, amoebae fall under eukaryotes because they have a true nucleus. Although not technically a true amoeba, Naegleria fowleri, more commonly known as brain-eating amoeba, is an amoeboid organism that can burrow its way into the human body through the nose. It mainly feeds on neurons, destroying brain tissue. Not surprisingly, the mortality rate of this infection is high at 97%.

Frequently Asked Question (FAQs)

Q1. What is the size of an amoeba?

Ans. The amoeba size tends to vary greatly, from 2.3 micrometers to up to 2 00,000 micrometers. The marine amoeboid Massisteria voersi size is just 2.3 to 3 micrometers in diameter.

Q2. Where does amoeba grow?

Ans. They live in ponds, soil, lakes, rivers, and forests. If you scoop up a handful of dirt in the woods, it will contain hundreds of thousands of amoebas.

Q3. Do amoebas have hearts?

Ans. No, an amoeba can not grow a heart. Amoeba is single-celled organisms. Hearts only exist in complex, multi-celled organisms that belong to the taxonomic kingdom Animalia. Hearts are made up of muse tissue.

Q4. Where do most amoeba live?

Ans. They can be found in warm fresh water, such as rivers and lakes. Geothermal water, such as hot springs. Warm water discharge from the industrial or the power plants.

Q5. How many cells does an amoeba have?

Ans. One cell