Microorganisms: Friend and Foe- Protozoa

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• Tertiary Education

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Now,  just as we did a quiz learning which hogwarts house we'd be in, we're going to learn about Protozoa- a type of microorganism among others.

Microorganisms: Friend and Foe

PROTOZOA

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 Organisms which we can't see from our naked eyes are called- Micro-organisms. Some microorganisms can be harmful to us and cause diseases while some can be useful to us  These microorganisms are mainly classified into 5 groups- Bacteria, Viruses, Protozoa and some Fungi and Algae.

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Protozoa are a group of single celled/unicellular microorganisms which are classified as animals, they're usually found in ponds, lakes, dirty water drains, damp soil etc. Some examples of protozoa are Ameoba, Paramecium, Entameoba and Plasmodium. 

Let's now watch a YouTube video to learn about Protozoa in detail.

Structure of Protozoa 

So, as we learned from the video, most of the protozoa are Heterotrophic, only a few exceptions have chlorophyll and are autotrophic. Most of them are parasitic and require a host body for nutrition and can cause diseases which gives rise to another concept- Vector-borne diseases.

Nutrition 

Vector-Borne Diseases

Disease that results from an infection transmitted to humans and other animals by blood-feeding anthropods, such as mosquitoes and fleas. Examples of vector-borne diseases include Dengue fever, Lyme disease, and Malaria.

HOTS: Imagine you're a mosquito who carried a disease to a 3 humans and though the disease is mainly caused by a protozoan, a lot of humans blame your species for it. How'd you feel? What are your thoughts?

Now, if the diseases are caused by protozoa, where does a mosquito come from? It's because the protozoan can't possibly enter your body like that, until it has a host. For example, for malaria- The protozoan lives as a parasite in the mosquito and slips into a human body while the mosquito sucks blood from it. The malaria causing Plasmodium (protozoan) enters the body in form of Sporozoites. Once the plasmodium is in the bloodstream, it eventually reaches it's target- the liver.

They attack the liver cells and stay in them for quite a long time but then they start reproducing asexually to increase their number. Then, they enter the blood stream by bursting out the liver cells. The form they release into the bloodstream is called the merozoites. Next, they target the RBCs and form a ring like structure called the Trophozoites. Next can have two fates- Either most of the trophozoites reproduce asexually to make more Merozoites. This happens exponentially, the number of Merozoites produced is too much for the RBC to contain, hence, the RBC burst, releasing them out, and the Merozoites keep attacking other RBCs to reproduce.

The other fate can be to enter a sexual cycle. In this, the Trophozoites give rise to two gametocytes. Gametocytes are like the germ cells of Plasmodium.

When a non-infected mosquito approaches the infected human for a blood meal, then these gametocytes quickly pass into the mosquito's body with the sucked blood. Now, in the mosquito's body, the two gametocytes fuse to form a zygote. From here, a structure called oocyst which crosses the gut wall and reaches the salivary gland which releases new Sporozoites which are ready to infected another body while the mosquito takes its next blood meal.

Thank you so much!