PROTOZOA
All are eukaryotic-having a nucleus.

65,000 species of protozoa.

All are heterotrophic.

Are either free-living or parasitic-living.

CLASSIFICATION

4 Different Phyla


Phylum Sarodina

Famous one is the Ameba genus.
40,000 species

Scavengers that feed on decaying organic matter in rivers, streams, and lakes.
Have flexible membranes.

Move using pseudopodia-cytoplasmic extensions that function in movement.

Cytoplasm-2 regions

Ectoplasm-Thin, slippery liquid in which the particles don't settle, directly inside the membrane.

Endoplasm-Exactly like ectoplasm except it's located in the interior of the cell.

How they move

When the protozoan moves, the endoplasm pushes outward with the help of the slippery ectoplasm and becomes a pseudopodia

It moves by amboid movement-internal flowing of the contents of the cell.


Keep water out

Usually hypertonic to environment and have a contractile vacuole which pushes the water out.

How they eat

Surround the water and ingest nutrients by phagocytosis-englufing the food.

Surrounds the food with its pseudopodia.
Closes together its cell membrane and pinches together in and the food is in a food vacuole.
Enzymes then digest the food.

Reproduction

They use binary fission-asexual and mitotic that produces identical offspring.
Usually takes less than an hour.

Phylum Ciliophora

Most famous is Paramecium.

8,000 Species

Live in freshwater and saltwater.
Move with cilia, which beat in synchronized strokes. The cilia causes the body of it to rotate and it moves forward.

Doesn't change it's shape like Sarcodina because it's surrounded with a rigid protein covering called a pellicle-covered with thousands of cilia arranged in rows.

Has two different kinds of nuclei.

Macronucleus-Much bigger      -Controls respiration, protein synthesis, digestion, and asexual reproduction.

Micronucleus-Involved in sexual reproduction digestion.

How they eat

Using an oral groove-cilia make water currents that sweep food down to the mouth of the paramecium. The mouth pore opens onto a gullet, which forms food vacuoles that move throughout the cytoplasm.
The vacuoles are digested and absorbed and waste is taken out the anal pore.

Reproduction

Usually uses binary fission. In that process the micronucleus divides by mitosis.
The macronucleus, which contain up to 500 times more DNA than the micronucleus, just stretches out and splits into two parts each going into a daughter cell.

Another way to reproduce is sexual reproduction called conjugation.

Two paramecium line up at their oral grooves.
Their macronucleus disintegrates.

Each micronucleus go through meiosis and produce four haploid micronucleus on each side.

3 of the micronucleus disappear.

The fourth, surviving one moves to the oral groove.
There it undergoes mitosis and produces two haploid micronuclei of unequal size.

The smaller one micronucleus exchanges with the smaller micronucleus from the other paramecium.

Now the micronucleus and macronucleus combine together to form diploid micronuclei. Then the two paramecium separate and macronuclei forms again.
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Phylum Zoomastigina

Use flagella to move.
The whipping of the flagella pushes or pulls the protozoan through the water.

Most are free-living, freshwater, and feed on small organisms.

Some are parasites.

Parasites-3 different kinds

Trypanosoma

Slender, flattened, with one posterior flagella.

Live in blood of their hosts (humans and animals) and are carried by means of bloodsucking organisms such as flies.

Trypanosomiasis (sleeping sickness)

Causes a fever and swollen lymph nodes.

Later stages, the parasites invade the brain causing uncontrollable sleepiness.

Occurs in two forms-
Gambian-takes several years to invade the brain

Rhodesian-affects the host more quickly and usually is fatal.

Both are transferred by the tsetse fly, which lives only in Africa.

Leishmania

Carried by sand flies

Causes the disease leishmaniasis which disfigures your skin sores and can be fatal.

Occurs in Africa, Asia, and Latin America.

Giardia

Carried by muskrats and beavers.

Causes the disease girdiasis, which gives you fatigue, diarrhea, cramps, and weight loss.

Drinking water that is contaminated with the disease will not affect muskrats and beavers but it can harm humans.

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Phylum Sporozoa

6,000 species

Have no means of moving.

All are parasitic.

Are carried in the blood of their hosts. They absorb the nutrients in the blood of their hosts.

Two kinds of sporozoans including Toxoplasm and Plasmodium cause diseases in humans.

Toxoplasma

In humans it causes the disease toxoplasmosis.

Few or no symptoms for adults but is often fatal to newborns because they don't have a developed immune symptoms.

Plasmodium

Has a complex life cycle with more than one host.

Causes malaria-kills 2 million people a year and happens most often in the tropics.


Mosquito bites a person and the Plasmodium spores enter the person's bloodstream and travel to the liver where they reproduce asexually.

New spores infect erythrocytes and continue asexual reproduction.

Every two or three days the spores break out of the erythrocytes and release toxins into the blood.

The toxins will eventually cause the liver and spleen to become enlarged and sometimes the kidneys end up failing.

Some of the spores develop into cells.

When the mosquito bites the person it takes in these cells.

Inside the mosquito the cells develop into gametes and combine to form a zygote.

The nucleus of the zygote divides internally many times and forms internal spores.

The spores move to the saliva glands of the mosquito and if the mosquito bites again, the process happens again.

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