Amoeba - Structure & Classification

Amoebas are small, single-celled creatures, which change shape and handle environments. Their internal structure is made up of parts such as the nucleus, cytoplasm, and plasma membrane. Relating to amoebas would be an integral part of entrance exams like NEET and JEE due to some possible questions that may refer to the brain-eating amoeba, how they gain food, and how they reproduce in the form of binary fission. This topic usually appears in chapters on cell biology or microbiology, particularly within the Kingdom Protista of Biology. Learning about amoebas is important for entrance exams like NEET and JEE, where topics such as the What is an amoeba, brain-eating amoeba (Naegleria fowleri), nutrition in amoeba, and binary fission in amoeba are frequently covered. A simple amoeba diagram can help illustrate these concepts.

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What Is Amoeba?

Scientists often ask, what is amoeba, to highlight its role as a basic form of life that plays a crucial part in various ecosystems. Amoeba is defined as a unicellular organism that can only be seen by a microscope and not by the naked eye. It is usually eukaryotic, meaning that it is a true organism that possesses true organelles and a nuclear envelope. It moves with the help of false feet called pseudopodia, and it is defined as the cytoplasm pushing off the cell membrane. The amoeba's main characteristic is its ability to change shape.

The brain-eating amoeba, Naegleria fowleri, is known for its ability to cause a rare and often fatal infection in humans called primary amoebic meningoencephalitis (PAM).

Structure Of Amoebas

• Movement in the amoeba occurs through false feet called pseudopodia, so it changes its shape.
• The structure of amoebas is differentiated into three parts: cytoplasm, plasma membrane, and nucleus.
• The cytoplasm of the amoeba is differentiated into two layers that are named as outer ectoplasm and inner endoplasm.
• The plasma membrane of an amoeba is usually very thin, and it is a double-layered membrane that is made up of protein and lipid molecules.
• When we talk about other cellular organelles, it contains contractile vacuoles, mitochondria, the Golgi apparatus, and some of the fat globules.
• The contractile vacuole is used to maintain the osmotic equilibrium by separating out most of the water from the cell.

The size of an amoeba

Amoeba usually differs in both size and shape. When the earliest animals were identified, they were approximately 400 to 600 micrometres in size. Many sizes of amoeba are extremely small, 2-3 nanometers in size and as well as exceptionally large such as 20 cm amoeba. The body is generally transparent, and it looks normally like gelatin.

Classification Of Amoeba

All the discussion of the amoeba and which domain and phylum it belongs to is defined here:

• Domain: Eukaryota (true cells)
• Kingdom: Amoebozoa
• Phylum: Tubulinea
• Order: Tubulinida
• Family: Amoebidae
• Genus: Amoeba
• Species: many different species, such as Proteus and Animacule.

Nowadays, studies have been focusing on classifying the amoeba based on the subunit present in its ribosomal RNA. Sarcodina is the most preferable and most accepted taxonomic group that belongs to the classification of the amoeba cell. It is classified based on its observable characteristics.

Reproduction In Amoebas :

Binary fission

• As one observes the microorganisms, one may wonder what an amoeba is and find out later on that it reproduces asexually through a method called binary fission.
• Binary fission in amoeba is a type of asexual reproduction where a parent cell splits into two identical daughter cells. In binary fission in amoeba, the organism first duplicates its genetic content prior to elongation of the cell and splitting down its middle.
• In amoeba, a binary fission is relatively fast. In ideal conditions, a full cycle usually takes under half an hour.
• It is of great importance to understand the process of binary fission of amoebas for a better appreciation of how such microorganisms multiply and maintain populations under varied types of environments.
• In binary fission in amoeba after karyokinesis has divided the nucleus, cytokinesis separates the cytoplasm into two cells that eventually can develop into an independent living organism.

Spore formation:

When there are unfavourable conditions, the amoeba divides with the help of spore formation. It starts to break its nuclear membrane, and some of the chromatin blocks get released into the cytoplasm. Each chromatin block now gets inside a nuclear membrane and becomes a small daughter nucleus.

How Does Amoeba Obtain Its Food?

• The question of how an amoeba obtains its food is taken care of through a simple explanation: It just forms a food vacuole when it catches the food using its pseudopodia.
• When interpreting how an amoeba acquires its food, such steps as ingestion, digestion, absorption, assimilation, and egestion need to take place within the organism.
• The process through which an amoeba gets its food is through the creation of a food vacuole after the cell engulfs the available nutrient that the organism finds in its surroundings.
• To come up with an answer for how an amoeba gets its food, first of all, it should be mentioned that the whole process of that mechanism occurs without specific organs as well but rather takes place due to the highly flexible nature of body structure of an amoeba.

Mode of nutrition:

Generally, there are five stages in the mode of nutrition

How To Be Safe From Brain Eating Amoeba?

• Warm freshwater lakes, for instance, can expose one to amoebas that feed on the brain. Amoebas may gain entry into one's body through the nostrils, and this would mean passage into a serious health condition.
• Public health personnel warn that the amoeba thrives under unkept swimming pools and hot tubs. Then, safety measures at water during the summer months are key.
• It was researching this particular amoeba that opened the window to the survival capabilities of the brain eating amoeba under intense heat, providing a good explanation for the reason it is found frequently in warm waters.
• While the name "brain-eating amoeba" certainly sounds ominous, it is worth noting that infections are incredibly rare and tend to occur under special conditions.

Tips, Tricks, and Strategies to Prepare for Amoeba

Additional Mnemonics for Effective Study

• Essential Amino Acids: "Any Help In Learning These Little Molecules Proves Truly Valuable"
• Arginine, Histidine, Isoleucine, Leucine, Threonine, Lysine, Methionine, Phenylalanine, Tryptophan, Valine.
• Taxonomic Rank: "Do Kindly Put Cover On Fresh Green Spinach"
• Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.
• Phases of Mitosis: "I Prefer Milk And Tea"
• Interphase, Prophase, Metaphase.
• Types of WBC (White Blood Cells): "Never Let Momma Eat Beans"
• Neutrophils (60%), Lymphocytes (30%), Monocytes (6%), Eosinophils (3%), Basophils (1%).

Weightage of Amoeba in Different Entrance Exams

Types of Questions Asked on Amoeba in Different Exams

What is amoeba is a question that leads to discussions about its classification under the Kingdom Protista and its significance in microbiology.

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