Protozoa Characteristics and Reproduction

Questions and Answers

What are the characteristics of Protozoa?

They are unicellular, chemoheterotrophs, have special structures for ingesting food and are capable of reproduction.

What are the 2 types of reproduction?

Sexual

Asexual

Both A and B (correct)

Neither A nor B

What are trophozoites?

Any stage in a protozoa's life cycle at which they ingest food; it refers to the motile form.

What are protozoa cysts?

They are a non-motile form protected by a membrane and usually the infective stage. Signup and view all the answers

How resistant are protozoa cysts?

They are not as resistant as a bacterial endospore. Signup and view all the answers

What is excystation?

It is the process of emergence of the trophozoite from the cyst. Signup and view all the answers

How can you kill a cyst?

Boil them. Signup and view all the answers

How long can protozoa cysts live in soil or water?

Months. Signup and view all the answers

Does a protozoa cyst go out and seek nutrients or ingest food?

False Signup and view all the answers

To ingest food, do protozoa cysts use organelles?

False Signup and view all the answers

What is a definitive host?

The host in which the parasite completes its sexual life cycle. Signup and view all the answers

What is an intermediate host?

The host where the organism lives temporarily but does not complete its sexual life cycle. Signup and view all the answers

What are the subphylums for Sarcomastigophora?

Sarcodina (amoebas) and Mastigophora (flagellates). Signup and view all the answers

What are examples of a Ciliata (ciliates)?

Paramecium spp and Balandtidium. Signup and view all the answers

What is a Sporoza, a non-motile obligate parasite?

Apicomplexia. Signup and view all the answers

How do amoebas move?

By pseudopods. Signup and view all the answers

How do flagellates move?

By flagella. Signup and view all the answers

What are in the Sarcomastigophora Phylum?

Amoebas and Flagellates. Signup and view all the answers

What is contained in the subphylum Sarcodina?

Amoebas. Signup and view all the answers

What are free living and non-parasitic?

Amoeba spp. Signup and view all the answers

What contain a nucleus and pseudopods?

Amoebas. Signup and view all the answers

In the Entamoeba histolytica, what is contained inside?

The nucleus and food vacuoles. Signup and view all the answers

What is the disease Amoebiasis?

A global disease that any traveler can get. Signup and view all the answers

What consumes red blood cells?

Entamoeba histolytica. Signup and view all the answers

Where can you see RBCs in the cytoplasm of the amoebas?

In a fresh diarrheal specimen. Signup and view all the answers

What is histolysis?

Destroying tissue. Signup and view all the answers

What are the characteristics of Entamoeba histolytica?

Bores through enteric walls to reach the bloodstream, can reach different vital organs. Signup and view all the answers

What is a typical effect of Entamoeba histolytica?

Liver abscess caused by migrating Entamoeba histolytica. Signup and view all the answers

What can Entamoeba histolytica infection lead to?

Amoebiasis or amoebic dysentery. Signup and view all the answers

What are symptoms of the above complications?

Dysentery, weight loss, fatigue, and abdominal pain. Signup and view all the answers

How can it be diagnosed?

By stool samples; trophozoites in a fresh fecal smear and cysts in an ordinary stool sample. Signup and view all the answers

What is commonly used to treat Entamoeba histolytica?

An antibiotic, Metronidazole. Signup and view all the answers

What are diagnostic features of Entamoeba histolytica?

Ingested RBC and Bull's eye Karyosome. Signup and view all the answers

What is Giardia lamblia?

An intestinal parasite with nuclei and flagella. Signup and view all the answers

What is Trichomonas vaginalis?

A urogenital parasite with nucleus and flagella. Signup and view all the answers

Study Notes

Characteristics of Protozoa

Unicellular organisms
Chemoheterotrophs: obtain energy by breaking down organic matter
Possess structures specialized for food ingestion
Reproduce through various modes

Types of Reproduction

Asexual reproduction includes fission, budding, and schizogony (rapid production of trophozoites)
Sexual reproduction occurs via conjugation

Trophozoites

Refers to any stage where protozoa ingest food, primarily the motile form
Motility achieved through structures like pseudopods, cilia, or flagella

Protozoa Cysts

Non-motile stage, often the infective form, encased in a protective membrane
Contain a thick cell wall for enhanced survival in harsh environments

Resistance of Protozoa Cysts

Not as resilient as bacterial endospores

Excystation

The process by which a trophozoite emerges from a cyst

Killing Cysts

Cysts can be destroyed by boiling

Duration of Cyst Survival

Protozoa cysts can survive for months in soil or water

Nutrient Absorption

Protozoa cysts do not seek out or ingest food actively, but absorb nutrients

Lack of Organelles in Cysts

Cysts lack organelles necessary for food digestion

Definitive Host

The host in which a parasite completes its sexual life cycle, e.g., Anopheles mosquito for Plasmodium

Intermediate Host

A temporary host where the organism lives but does not complete its sexual life cycle, humans often serve this role

Subphylums for Sarcomastigophora

Sarcodina (amoebas) and Mastigophora (flagellates)

Examples of Ciliates

Paramecium spp. and Balantidium (parasitic ciliate causing disease)

Sporozoa Classification

Apicomplexa as a group of non-motile obligate parasites

Movement Mechanisms

Amoebas move using pseudopods
Flagellates utilize flagella for movement

Contents of Sarcomastigophora Phylum

Includes amoebas and flagellates

Sarcodina Subphylum Contents

Exclusively contains amoebas

Free-Living and Non-Parasitic Examples

Species like Amoeba spp.

Structure of Amoebas

Characterized by a nucleus and pseudopods (false feet)

Features of Entamoeba histolytica

Contains a nucleus and food vacuoles

Amoebiasis Disease Overview

A globally prevalent disease, risk increases upon entering regions like Mexico

RBC Consumption

Entamoeba histolytica consumes red blood cells

Detection of RBCs

Presence observed in fresh diarrheal specimens

Histolysis

Refers to the destruction of tissue

Pathogenic Behavior of Entamoeba histolytica

Invades intestinal walls and can spread to other vital organs (liver, lungs, brain, eyes)

Effects of Entamoeba histolytica Infection

Can cause liver abscesses, potentially fatal if untreated

Complications from Entamoeba Histolytica Infection

Results in amoebiasis or amoebic dysentery

Symptoms of Complications

Symptoms include dysentery (diarrhea), weight loss, fatigue, and abdominal pain

Diagnosis of Infection

Diagnosis through stool samples; fresh fecal smears show trophozoites and cysts in ordinary stool samples

Treatment for Entamoeba Histolytica

Commonly treated with the antibiotic Metronidazole

Diagnostic Features of Entamoeba Histolytica

Characterized by ingested red blood cells and bull's eye karyosome

Giardia lamblia Characteristics

Intestinal parasite featuring nuclei and flagella

Trichomonas vaginalis Characteristics

Urogenital parasite also featuring a nucleus and flagella

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Description

Explore the fascinating world of protozoa through this quiz. Understand their unique characteristics, various reproduction methods, and the role of trophozoites. Perfect for students diving into microbiology or life sciences.