40 Fun Facts About Amoeba

The brain-eating amoeba Naegleria fowleri infects people only when water enters through which part of the body?

The nose is the only way in: the amoeba follows the smell nerves up to the brain, while swallowing the same water is harmless. Infections are extremely rare but almost always fatal.

Which programming language was first developed for Amoeba, an operating system built at a university in Amsterdam?

Python was written by Guido van Rossum, who wanted a scripting language that could talk to Amoeba. The system made a whole network of computers behave like a single machine.

A German naturalist who drew the first known amoeba in 1755 named it after which shape-shifting Greek sea god?

Proteus could take any form to slip away from those who caught him, so the ever-shifting pond creature became 'the little Proteus'. The same god gave English the word protean.

Which of the human body's defenders crawl like an amoeba to chase down and engulf invading germs?

White blood cells pursue bacteria and wrap around them, just as a pond amoeba takes its prey. Biologists even call their crawling style amoeboid movement.

Which 1958 horror film gave Steve McQueen his first leading role, battling an amoeba-like alien in Pennsylvania?

The Blob stars a carnivorous jelly that arrives inside a meteorite and swells with every victim it absorbs. McQueen was paid just $3,000 for the part.

Starving Dictyostelium amoebas gather by the thousand into one crawling body nicknamed after which garden creature?

A slug of up to 100,000 cells, only 2 to 4 mm long, creeps toward light and warmth as if it were a single animal. Loners that team up this way are known as social amoebas.

An amoeba once named Amoeba dubia is reported to carry about 200 times as much of what as a human cell?

DNA in this pond amoeba was measured at 670 billion base pairs, against about 3 billion in a human genome. Researchers urge caution, because the figure predates modern methods.

Acanthamoeba, an amoeba found in soil and tap water, causes a painful eye infection mostly among people who wear what?

Contact lenses rinsed in tap water or worn while swimming can trap the amoeba against the eye. Ordinary multipurpose lens solutions do little to kill it.

Found inside an amoeba in 1992, which kind of microbe was so large that scientists first mistook it for a bacterium?

A virus, later named Mimivirus for 'mimicking microbe', was hiding in an amoeba collected in Bradford, England. Only in 2003 did researchers work out what it really was.

A freshwater amoeba must keep pumping out water with its contractile vacuole, or its single cell would do what?

It would burst, because water seeps into the saltier cell by osmosis without pause. Marine amoebas usually lack the pump, since seawater matches their insides.

The name amoeba, first coined as Amiba by a French naturalist in 1822, comes from a Greek word meaning what?

Change is the sense of the Greek amoibe, a nod to a body that never holds one outline for long. Bory de Saint-Vincent picked the name, and a German naturalist later respelled it Amoeba.

The name of the pseudopods an amoeba uses to crawl and to seize food translates into English as what?

False feet is the literal meaning: each pseudopod is a temporary bulge that flows forward and later melts back into the body. An amoeba can push out several at once.

Carl Linnaeus filed the first described amoeba under which name, now a genus of giant amoebas?

Chaos was the name Linnaeus gave the shapeless creature. The genus now holds giant amoebas that reach 5 mm long, big enough to spot without a microscope.

The Amoeba Boys, a trio of dimwitted would-be villains, appear in which Cartoon Network series?

The Powerpuff Girls seldom need to fight them: the three mutant amoebas, who speak with Brooklyn accents, long to be respected criminals but are too incompetent to manage it.

Entamoeba histolytica, an amoeba spread by contaminated food and water, causes which disease of the gut?

Dysentery of the amoebic kind strikes when the parasite attacks the lining of the bowel. Tens of millions of people carry it, though many never feel ill.

Being neither animal, plant nor fungus, an amoeba belongs to which catch-all group of mostly single-celled life?

Protists are simply the complex-celled organisms left over once animals, plants and fungi are set aside. That makes the group a grab bag of unrelated branches, not one family.

Unlike plants and fungi, an amoeba can freely reshape itself because it lacks which stiff outer layer?

A cell wall would lock the amoeba into one outline, as it does every cell of an oak or a mushroom. With only a flexible membrane around it, the amoeba can flow in any direction.

Syringammina fragilissima, an amoeba-like single cell that grows up to 20 centimetres across, lives in which habitat?

The deep ocean floor is home to this giant, first dredged up off Scotland in 1882. Its one cell spreads through hundreds of branching, sediment-crusted tubes that crumble at a touch.

With no partner needed, a common pond amoeba reproduces by which simple method?

Splitting in two, known as binary fission, yields a pair of identical amoebas. If one is cut apart by force, usually only the piece holding the nucleus survives.

When a pond dries out, an amoeba can survive by rolling into a ball inside a protective coat called what?

A cyst is the amoeba's emergency shelter: the cell sheds most of its water, seals itself in and lies dormant until conditions improve. It cannot feed or divide while shut inside.

Which process, whose name means 'cell eating', does an amoeba use to wrap around and swallow prey whole?

Phagocytosis ends with the victim sealed in a pocket inside the amoeba, where it is slowly digested. A big pond amoeba can even swallow rotifers, which are tiny many-celled animals.

Gromia sphaerica, a giant single-celled amoeba found off Oman and the Bahamas, is said to resemble which fruit?

A grape is the usual comparison, right down to the soft skin. As it creeps through mud, Gromia leaves trails like fossil tracks 1.8 billion years old that were once credited to early animals.

Which bacteria, behind a pneumonia first seen at a 1976 veterans' convention in Philadelphia, multiply inside amoebas?

Legionella uses amoebas as its main hosts, breeding inside them in cooling towers, showers and spas. It takes its name from the American Legion, whose members fell ill at the convention.

The first amoeba ever described in humans lives around which part of the body?

Gums are its home, in the pockets at the base of the teeth, and it can pass between people with a kiss. It turns up in 95% of people with gum disease but rarely in healthy ones.

In a 2010 study, the amoeba-like slime mould Physarum polycephalum grew a network matching which city's railways?

Tokyo and 36 nearby towns were marked out with oat flakes, and the brainless yellow slime mould joined them with feeding tubes about as efficient as the real train system.

Shell-building amoebas such as the pond genus Difflugia make their portable homes by gluing together grains of what?

Sand grains, picked up and cemented into a neat case, make a Difflugia shell. When the amoeba divides, it hands its spare building material to the daughter cell.

Biologists call the clear outer layer of an amoeba by which word, also used for the ghostly substance of séances?

Ectoplasm is the clear gel just under an amoeba's skin, wrapped around a grainy inner core. In 1894 psychical researcher Charles Richet gave the same name to the stuff mediums claimed to produce.

The brain-eating amoeba Naegleria fowleri honours Malcolm Fowler, who described the first cases in which country?

Australia saw the first recognised cases in the 1960s, written up by Fowler at Adelaide Children's Hospital. The amoeba thrives in warm fresh water, from lakes to poorly chlorinated pools.

Radiolarians, amoeba-like sea drifters drawn in detail by Ernst Haeckel, build their lacy skeletons from which material?

Silica, the raw material of glass, gives radiolarians skeletons tough enough to survive as fossils from the Cambrian onwards. Geologists use them to work out the age of rocks.

Coin-shaped fossil shells of nummulites, giant amoeba-like sea creatures, fill the limestone of which ancient monuments?

The Giza pyramids are built from limestone packed with nummulites, each the shell of a single cell. The ancient writer Strabo took the little discs for lentils dropped by the builders.

Balamuthia, a brain-infecting soil amoeba, was first found in 1986 in which animal at a San Diego wildlife park?

A mandrill that died at the San Diego Wild Animal Park gave science both its first look at the amoeba and the species name mandrillaris. It can get into the body through open wounds.

An amoeba pushes out each pseudopod with filaments of which protein, also vital to human muscle contraction?

Actin filaments assemble inside the advancing bulge and shove the cell's surface outward. In our muscles the same protein slides against myosin to produce every movement.

If the gut amoeba Entamoeba histolytica reaches the bloodstream, it most often forms abscesses in which organ?

The liver is where the parasite most often ends up once it escapes the intestine. An amoebic abscess can form there even in someone who never had diarrhoea.

The brain-eating amoeba Naegleria fowleri can turn from a crawler into a swimmer by growing a pair of whip-like what?

Flagella sprout when the amoeba lands in very dilute water, turning it into a pear-shaped swimmer for a while. That double life earns it the label amoeboflagellate.

Vampyrella, known as the vampire amoeba, bores into and drains the cells of which pond organisms?

Algae such as Spirogyra are its victims: the bright red amoeba cuts a hole in one cell, sucks out the green contents within minutes and swells as it feeds.

Some round amoeba-like microbes bristle with stiff radiating spikes, earning a common name taken from which object?

The Sun inspired both the common name, sun-animalcules, and the 'helio' in heliozoan. The rays are sticky arms stiffened by tiny internal tubes and used to snare passing prey.

August Johann Rösel von Rosenhof, who published the first drawings of an amoeba in 1755, made his living as what?

A miniature painter by trade, Rösel earned enough from portraits to spend his spare hours watching insects, frogs and pond life. His detailed plates made him a major figure in the study of insects.

Paulinella chromatophora, an amoeba found in the Rhine in 1894, long ago captured cyanobacteria and can now do what?

It can photosynthesise, because the captured cyanobacteria became permanent solar panels inside the cell some 90 to 140 million years ago. Plants' ancestors are the only others known to have managed it.

Amoebas with no shell at all, unlike their house-building testate cousins, are described by which blunt adjective?

Naked amoebas, formally called gymnamoebae, include the classic shapeless pond species. Their testate relatives carry hard cases that they either secrete or piece together themselves.

When social amoebas build a spore tower, some die to lift their neighbours into the air by forming which part?

The stalk is made of amoebas that give up their own chance to reproduce: around 20% of the group dies so that the rest can be raised up and scattered as spores.