Animal Kingdom Test 12

Amoeba orients in directive illumination and is negative in strong light and probably positive in very weak light, since strong light causes inhibition in the formation of pseudopods .

Pseudopodia is a temporary cytoplasm-filled projection of a eukaryotic cell membrane or a unicellular protist.
Pseudopods may be used for motility, or for ingesting nutrients or other particulate matter. It senses the prey that can then be engulfed; the engulfing pseudopodia are called phagocytosis pseudopodia. Hence, pseudopodia in amoeba help in locomotion, engulfment and ingestion.
Hence the correct option is B.

Pseudopodia are temporary finger like projections with blunt rounded tips which are constantly being given out or withdrawn by the body. Many pseudopodia are formed simultaneously. Amoeba exhibits movement by the pseudopodia. It also helps in food capture.

Contractile vacuoles are the specialized structures which store extra fluid materials and help in throwing them out of the cell. They also act in osmoregulation(maintaining water balance). They are generally seen in fresh water protistans, algae and amoeba.

Amoeba takes in its food through this process. Initially, it pushes out its pseudopodia so that it can encircle the food. After this, it engulfs the food, thus forming a bag-like structure called food vacuole. The process is known as “phagocytosis”.

We know that amoeba is a unicellular organism which lives in fresh water.So in amoeba respiration takes place through its cell membrane also called plasma membrane. Amoeba gets oxygen gas dissolved in surrounding water through its plasma membrane by the process of diffusion.

Amoeba is a fresh water unicellular organism. In amoeba the excretory waste is ammonia. The excretory waste present in the cytoplasm is collected by contractile vacuole then this excretory waste i.e NH3 is excreted through plasma membrane by diffusion.
So, the correct answer is 'Plasmalemma'.

Amoeba is an important protozoa found in fresh water. It feeds on microscopic plants and animals present in water. The mode of nutrition in amoeba is Holozoic. And the process of obtaining food by amoeba is called phagocytosis. 

For, binary fission, Amoeba requires one parent cell. In the process of binary fission, a fully grown cell divides into two equal halves forming two daughter cells.

It is the most common method of asexual reproduction that occurs in prokaryotes and some single-celled eukaryotes, i.e.,  Amoeba.

Budding is a type of asexual reproduction  which do not involve fusion of gametes. A new organism develops from an outgrowth or bud due to cell division at one particular site. The bud remains attached to the parent plant and separates after it gets mature. It leaves a scar at the point of separation. The newly developed organism is a clone to its parent cell. 
Sporulation is the process of production of spores which germinates under favorable condition. During favourable condition the encysted amoeba divides by multiple fission and produces pseudopodiospores. This phenomenon is known as sporulation. In order to survive, the unfavorable condition amoeba develops a tough wall around it known as cyst. When the favorable condition approaches the cyst wall bursts out, and the spores are released in the surrounding medium to grow up into many amoebae.
Fragmentation is a mode of asexual reproduction which involves breaking the parent body into several fragments and each fragment develops into a new individual.
Regeneration is the process of development of lost or damaged part.
So, the correct answer is option C.

“During adverse environmental periods many amoebas survive by encystment: the amoeba becomes circular, loses most of its water, and secretes a cyst membrane that serves as a protective covering. When the environment is again suitable, the envelope ruptures, and the amoeba emerges.”

Mast in 1926

Amoeba proteus contains a central elongated fluid portion (plasmasol), a rigid layer surrounding this (plasmagel), a thin elastic surface layer (plasmalemma), and a hyaline layer between the plasmagel and the plasmalemma which is fluid at the tip of active pseudopods and in certain other regions.

The plasmasol is an emulsion. It consists of a fluid in which various vacuoles and granuoles are suspended. The plasmagel is probably alveolar in structure. It contains the same kinds of substances as the plasmasol, but some of the fluid appears to be gelated so as to form alveoli. The plasmalemma probably consists of interwoven protein fibers and a lipoid which fills the interstices.

The plasmasol is probably hypertonic; the plasmagel and the plasmalemma are probably semipermeable. This and other factors result in an excess inflow of water, stretching the plasmagel and the plasmalemma. When a pseudopod is formed, the inner portion of the plasmagel liquefies locally. This produces a local decrease in elastic strength resulting in the formation of a protuberance, a pseudopod. As this is formed there is contraction at the posterior end, resulting in forward flow of the plasmasol and extension of the pseudopod.

If the pseudopod is attached, the plasmalemma, being attached to the substratum and to the adjoining plasmagel, slides over the plasmagel above and remains stationary below, rolling movement results. If it is free, the plasmalemma is stretched out with movement in it equal on all sides. If the free pseudopods become attached to the substratum at the tip after they are thus formed, walking movement results.

During locomotion of either type, the plasmasol continuously gelates at the tip of the extending pseudopods forming plasmagel, and the plasmagel continuously solates at the posterior end forming plasmasol.

Response is due largely to changes in the elastic strength of the plasmagel in the adhesiveness of the plasmalemma and in turgidity.

Locomotion in Amoeba verrucosa is in principle the same as it is in Amoeba proteus.

First, the amoeba cell undergoes nuclear division and replicates into two nuclei.The cell then produces protiens and nutrients in preperation for binary fission. In the stage of binary fission, the cell divides and forms 2 daughter cells. This process generally occurs when environmental conditions are most favourable.

Because contractile vacuole performs the function of Osmoregulation, hence it is analogous( similar in function) to Uriniferous tubules of frog(also a vertebrate).

Amoeba is an unicellular organism which doesn't need any skeleton or skeleton-like structure to protect that single cell, or to give a shape to that single cell or do anything that a skeleton performs. But it surely needs locomotion, reproduction, digestion like any other organism so as to survive. So it has counterparts for the rest of the 3 functions & not the skeleton.

The trichomonads and trypanosomes have a distinctive undulating membrane between the body wall and a flagellum. Many other structures occur in parasitic protozoa, including the Golgi apparatus, mitochondria, lysosomes, food vacuoles, conoids in the Apicomplexa, and other specialized.

Option A is correct as because cockroach uses it's legs for movement and locomotion similarly amoeba uses the pseudopodia for its movement.

The amoeba feeds on other protozoans and unicellular algae by engulfing them in its pseudopodia. This "cell eating" phenomenon (called phagocytosis) is also exibited by human white blood cells called phagocytes.

Amoeba Proteus reacts negatively when touched at any point with a solid object, the part affected contracts and the animal moves away. A floating Amoeba with spread pseudopodia, responds positively to contact with the solid object by fastening to it.

A pseudopod or pseudopodium is a temporary cytoplasm-filled projection of an eukaryotic cell membrane or a unicellular protist. Pseudopods may be used for motility, or for ingesting nutrients or other particulate matter. Cells that make pseudopods are generally referred to as amoeboids.

Amebiasis is the infection of the human gastrointestinal tract by Entamoeba histolytica, a protozoan parasite that is capable of invading the intestinal mucosa and may spread to other organs, mainly the liver.

Contractile vacuole helps in regulation of osmotic pressure. as entamoeba histolytica has no contractile vacuole, it cant regulate osmotic pressure and hence dies.

Entamoeba gingivalis is an opportunistic Amoebozoa (reported by some as an effect of disease; not a cause [hence status as a commensal]) and is the first amoeba in humans to be described. It is found in the mouth inside the gingival pocket biofilm near the base of the teeth, and in periodontal pockets.

The housefly is a fly of the suborder Cyclorrhapha. It is believed to have evolved in the Cenozoic era, possibly in the Middle East, and has spread all over the world as a commensal of humans. It is the most common fly species found in houses.Entamoeba histolytica is a protozoan parasite that is the second leading cause of parasitic death, after malaria. The amoeba is acquired by the fecal-oral route. Cysts are commonly found in contaminated drinking water in tropical areas with poor sanitation.

Binary fission is a form of asexual reproduction in which a cell splits into two identical copies. E. histolytica is a parasite that causes amoebic dysentery in humans. The parasites are passed in faeces, and can survive outside the body as long-lasting cysts, which revert to the active trophozoite stage when ingested.

Amebic Brain Abscess. Entamoeba histolytica is the second leading cause of death from parasitic disease worldwide. Ingestion of the quadrinucleate cyst of E. histolytica from fecally contaminated food or water leads to intestinal amoebiasis. ... They can invade through the portal circulation and cause liver abscesses.