Overview of protozoa

Overview of Protozoa

Biology

Lipscomb Academy

Characteristics

• Definition- ANIMAL-LIKE PROTISTS single-celled microscopic organisms that are noted for their ability to move independently

Characteristics

• Most are heterotrophic– Break down small molecules or cells in food

vacuoles

Characteristics

• Some are free-living and others are parasitic

Some human diseasescaused by protozoa are

malariaamebic dysentery,

and giardiasis

Reproduction

• Asexual- usually by binary fission• Some sexual by conjugation- an exchange

of genetic material

Classification

• Domain- Eukarya• Kingdom- Protista

– Along with algae, slime molds, and water molds

• Four phyla are usually used– Protozoa– Ciliophora– Sarcomastigophora– Apicomplexa

Adaptations

• Eyespot- localized region of pigment that can detect changes in the quantity and quality of light

• Cyst- dormant form of a protozoan that has a hardened outer covering to help them survive harsh conditions

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Phylum Protozoa

• Hundreds of species of ameba• Live in sand; mud; rocks; and shallow,

slow moving streams and ponds

Phylum Protozoa

• Pseudo- false• Podia- foot• Pseudopodia- cytoplasmic extensions

pushed out from the amoeba

Phylum Protozoa

• Endoplasm- the inner portion of the cytoplasm

• Ectoplasm- the outer layer of the cytoplasm

Phylum Protozoa

• Pseudopodia is used for feeding

Phylum Protozoa

• Some are covered with a protective shell or test

• Foraminifera- tests made of calcium carbonate

Phylum Protozoa

• Radiolarians

Phylum Protozoa

• Human Disease – Amebic dysentery

Phylum Ciliophora

• 8000 species• Paramecium-

large group of ciliates

• Feed on bacteria and algae

• Covered with cilia

Phylum Ciliophora

• Pellicle- clear elastic layer of protein that surrounds the cell membrane

• Oral Groove- funnel-like depression lined with cilia that sweeps food down into the mouth pore

Phylum Ciliophora

• Gullet- forms food vacuoles• Anal pore- where waste is expelled• Macronucleus- multiple copies of DNA and

sexual reproduction

Phylum Ciliophora

• Micronucleus- exchange during conjugation

• Reproduction– Binary fission– Sexual- conjugation

Phylum Ciliophora

Phylum Sarcomastigophora

• 2,500 species• One or more flagella• Primitive protozoa• Giardia lamblia


• Human Disease– Genus Trypanosoma

• Carried from host to host by blood sucking insects


• Human Disease– Trypanosomiasis- African sleeping sickness

• Tsetse fly


• Human Disease– Chagas’ disease

• Trypanosoma cruzi• Fever and severe heart damage

Phylum Apicomplexa

• 6,000 species• Adult forms have no means of

locomotion• Most are parasitic• Toxoplasmosis- a disease that

usually causes no problem in an adult but can harm a developing fetus- common in domestic cats

Phylum Apicomplexa• Plasmodium- malaria

– Severe chills, fever, headache, sweating, fatigue, and great thirst

– Vector- female anopheles mosquito

Education

Overview of protozoa