protozoa

Diagrams of different types of protozoa

Amoeba Shelled amoeba

Flagellates Ciliates – suctoria

Ciliates – peritrichus Heliozoanes

Protozoan life styles

Free living vs. symbiosis Photosynthetic(autotrophy) Combinations(hetrotrophy) Absorb solutes(osmotrophy) Ingest particulates(phagotrophy)-

predation on bacteria and other protozoa.

Pinocytosis (fluid uptake)

Free living forms Factors affecting distribution of free living

forms Nacl concentration, pH, Temperature, Oxygen requirements.

FREE LIVING FORMS

Nutrition --free living forms – phagocytosis of

particulate matter. --Complex nutritional needs. --All are chemoheterotrops . --Storage products –glycogen , starch and

lipids.

symbiosis•One organism lives on other organism , called the host.eg.-cuckoo(koel) and the crow. •The host is harmed, but usually survives.

Parasitism

•One organism benefits and the other neither benefits nor is harmed.•Example-Orchid growing on a mango tree.

Commensalism

•Both organisms are benefited from the relationship.•Example-association of fungus and algae.

Mutualism

Pinocytosis , osmotrophy

Osmotrophy is the uptake of dissolved organic compounds by osmosis for nutrition

Pinocytosis, a process by which liquid droplets are ingested by living cells. It is a process by which cells engulf external substances, gathering them into special membrane-bound vesicles contained within the cell. In pinocytosis, rather than an individual droplet of liquid traveling passively through the cell membrane, the droplet first becomes bound, or adsorbed, on the cell membrane, which then invaginates (forms a pocket) and pinches off to form a vesicle in the cytoplasm.

Asexual

1. Fission - characterized by division of the body into two or more

parts, each of which develops into a complete individual. 2. Budding - self supportive cell sprouts from & detaches from the

parent organism.3. Schizogony - a multiple fission type; the nucleus undergoes multiple

divisions before the cell divides.

Sexual1. Conjugation - the simplest form of reproduction. Two single-celled

organisms link together, exchange genetic information, & then separate.

- Reproduction -

Schizogony

conjugation

Conjugation in Protozoa is a two-way process, genetic material is passed between each conjugant.

The process of union of two gametes to form a zygote. It involves both plasmogamy and karyogamy.

The macroconjugants resemble the normal feeding individuals.

The microconjugants resemble the swarmers, although smaller.

Conjugation

Life stages of protozoa

The life stages of protozoa are:-1. Cyst – latent survival form.2. Trophozoite - The active motile stage of

protozoan parasite or active pathogenic vegetative state.

Encystment

- Some protozoa are coated with a protective capsule called cyst.

Cyst permits organism to survive when food & oxygen are lacking or when temperature is not suitable & toxic chemicals are present.

- Cyst is a reproductive structure in which new cells are produced asexually.

- The breaking of cyst is called excystation.

CystTropozoites

It is the only photogenic amoeba found in the animal intestine.

Entamoeba histolytica is the causative agent of amoebic dysentery.

Protozoan Disease of Nervous System

African

Trypanosomiasis It is named as

sleeping disease that is caused by tyrpanosoma brucei gambience & trypanosoma brucei rhodesiense-flagellates that are injected by tsetse fly.

Question

Do all mosquito bite human beings ?

Both males and females obtain some nutrition from flower nectar, but it is only the females that feed on blood to acquire the extra protein boost needed to produce and lay eggs.

Male mosquitoes do not bite human beings. They live on plant juices, other natural liquids from plants and decomposing organic material.

Protozoan Disease for Cardiovascular System

1. Malaria - A protozoan

cardiovascular disease caused by anopheles mosquito through injection of protozoan parasite

plasmodium.

Species caused malaria

Plasmodium malariae, Plasmodium ovale, Plasmodium vivax, Plasmodium flaciparum.

Plasmodium life cycle

- Anopheles mosquito feeds on blood & serves as the vector.

- Sporozoites enter blood stream and proceed to the liver within 30 min to infect hepatocytes.

- 1 week = Multiplication & transformation in the liver leads to the release of about 5,000-10,000 merozites PER HEPATOCYTE infected with only one sporozite!

- Merozites infect red blood cells, initiating the symptoms and pathology of malaria.

- Merozites replicate and differentiate again

- Cell ruptures to release new merozites (which will infect more red blood cells)

- Some merozites differentiate into ♂ and ♀ gametocytes.

- Gametocytes ingested by Female Anopheles differentiate into male and female gametes which fuse to form a zygote and become sporozites in the salivary gland….

Symptoms

- Chills, fever, sweating—peak every 48hrs.

- Weak, anemic, splenomegaly.

- Blocked capillaries = intense headaches, renal failure, heart failure, or cerebral damage.

Diagnosis - The most common diagnostic test is the

blood smear.

Treatment- Drug quininine, chloroquine, primaquine,

& mefloquine.

Disease caused by protozoa to human beings

Disease Casual agents Organs affected vector

1. Amoebiasis Entamoeba histolytica

Intestine, Liver Water

2.African Sleeping Sickness

Trypanosoma brucei

Blood, Brain Tsetse fly ( Glossina)

3.Leishmaniasis ( Kala - azar)

Leishmania donovani

White Blood Cells,Skin, Intestine

Sand fly ( Phlemotomus)

4.Malaria Plasmodium spp. Liver, Red Blood Cells

Mosquito ( anopheles)

5. Babesiosis Babesia microti Red Blood Cells Tick ( Txode)

Importance

Protozoa play important roles in the fertility of soils. By grazing on soil bacteria, they regulate bacterial populations and maintain them in a state of physiological youth in the active growing phase. This enhances the rates at which bacteria decompose dead organic matter. Protozoa also excrete nitrogen and phosphorus, in the form of ammonium and orthophosphate, as products of their metabolism, and studies have shown that the presence of protozoa in soils enhances plant growth.

Protozoa play important roles in wastewater treatment .

Good-quality, clean effluents are produced in the presence of large ciliated protozoan communities because they graze voraciously on dispersed bacteria and because they have the ability to flocculate suspended particulate matter and bacteria. Importance

Protozoa probably play a similar role in polluted natural ecosystems. Indeed, there is evidence that, by feeding on oil-degrading bacteria, they decrease bacterial growth in much the same way they enhance rates of decomposition in soils, thereby speeding up the breakdown of oil spillages.

Importance

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