Sarcodina and Amoeba Overview

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which of the following is a distinguishing feature of Entamoeba histolytica?

Contains bacteria in food vacuoles (correct)

Has a regular distribution of chromatin granules

Lacks a cystic wall (correct)

Contains RBCs in food vacuoles

Entamoeba coli has a cystic wall.

True

Name one of the four species of Plasmodium that causes malaria in humans.

Plasmodium vivax

The infective stage of Entamoeba histolytica is known as the ______.

cyst Signup and view all the answers

Match the following stages of Plasmodium sp. life cycle with their descriptions:

Exerythrocytic cycle = Liver stage of development Erythrocytic cycle = Human blood stage Gamogony = Sexual cycle inside the mosquito Sporogony = Asexual reproduction in mosquito haemolymph Signup and view all the answers

Which structure helps Apicomplexa parasites penetrate their host?

Apical complex Signup and view all the answers

Plasmodium sp. is solely transmitted through contaminated water.

False Signup and view all the answers

The __________ are intracellular blood parasites of birds and mammals that cause malaria in humans.

Plasmodium species Signup and view all the answers

Which of the following is NOT a type of habitat for Sarcodina protozoans?

Symbiotic Signup and view all the answers

Amoeba generally lives in low-oxygen environments.

False Signup and view all the answers

What is the function of pseudopodia in amoeba?

Locomotion and feeding Signup and view all the answers

Entamoeba histolytica is classified as a __________ endoparasite.

dangerous Signup and view all the answers

Match the following amoebae with their characteristics:

Entamoeba coli = Lives as a commensal in the large intestine Entamoeba histolytica = Causes amoebic dysentery Entamoeba gingivalis = Buccal commensal Amoeba proteus = Representative of free-living amoebae Signup and view all the answers

Which of the following statements about Entamoeba coli is true?

It lives in the lumen of the large intestine as a commensal. Signup and view all the answers

The ectoplasm and endoplasm of Entamoeba histolytica are well differentiated.

True Signup and view all the answers

Amoeboid movement in amoeba is caused by changes in the colloidal protoplasm from a fluid '_________' to a solid 'gel' condition.

sol Signup and view all the answers

Study Notes

Sarcodina (Amoebozoa)

Sarcodina are protozoans with a thin protoplasmic membrane and no defined shape
They move and feed using pseudopodia
Sarcodina can be free-living, commensal or parasitic
Amoeba proteus is an example of a free-living Sarcodina
Amoeba proteus lives in well-oxygenated freshwater habitats, often on decaying vegetation

Amoeba proteus

Amoeba proteus uses contractile vacuoles to regulate water through osmosis
Amoeba proteus uses temporary pseudopodia to move and capture food
Amoeba proteus exhibits amoeboid movement, a process where the colloidal protoplasm transitions from a fluid state ("sol") to a more solid state ("gel")

Parasitic Amoebae

There are six genera of parasitic amoebae
These parasites live in the intestinal tract (five genera) and the buccal cavity (one genus)

Entamoeba coli

Entamoeba coli is an intestinal commensal
Entamoeba coli feeds on bacteria

Entamoeba histolytica

Entamoeba histolytica is an intestinal parasite
Entamoeba histolytica feeds on tissues and blood of the host
Entamoeba histolytica can cause amoebic dysentery

Entamoeba gingivalis

Entamoeba gingivalis is a buccal commensal

Comparing Entamoeba histolytica and Entamoeba coli

Entamoeba coli lives in the lumen of the large intestine, while Entamoeba histolytica lives in the wall of the large intestine
The ectoplasm and endoplasm are not clearly differentiated in Entamoeba coli, but are well differentiated in Entamoeba histolytica
Entamoeba coli has two pseudopodia, while Entamoeba histolytica has a large single pseudopodium
The karyosome in Entamoeba coli is lateral, while the karyosome in Entamoeba histolytica is central
Entamoeba coli has irregularly distributed chromatin granules, while Entamoeba histolytica has regularly distributed chromatin granules
Entamoeba coli food vacuoles contain bacteria, while Entamoeba histolytica food vacuoles contain red blood cells (RBCs)
Entamoeba coli precysts can be round or oviod in shape
Entamoeba coli precysts lack a cystic wall
Entamoeba coli cysts contain glycogen and rod-shaped chromatoid bodies, while Entamoeba histolytica cysts contain glycogen but lack chromatoid bodies
Entamoeba coli mature cysts have 8 nuclei, while Entamoeba histolytica cysts have 4 nuclei

Phylum Apicomplexa

Apicomplexa are protozoan parasites that are endoparasites in higher animals
They are intracellular blood parasites found in blood cells and tissues of birds and mammals
Apicomplexa cause a variety of diseases
Apicomplexa are transmitted by blood-sucking arthropods which act as intermediate hosts

Plasmodium sp.

There are four species of Plasmodium that infect humans
Each species is responsible for a different type of malaria
The four species are:
- Plasmodium vivax
- Plasmodium malariae
- Plasmodium ovale
- Plasmodium falciparum
Each species infects red blood cells (erythrocytes) in humans
Plasmodium can also infect white blood cells (leukocytes)

Life Cycle of Plasmodium sp.

The life cycle of Plasmodium sp. is divided into three phases:
- Exerythrocytic cycle (Liver stage)
- Erythrocytic cycle (Human blood stage)
- Mosquito stage

Exerythrocytic Cycle

The exerythrocytic cycle takes place in the liver of humans
The cycle starts as a sporozoite injected by the mosquito
The sporozoite develops into a merozoite, which then infects red blood cells (erythrocytes)

Erythrocytic Cycle

The merozoite multiplies rapidly in red blood cells by schizogony
This creates a new generation of merozoites that are then released into the bloodstream
These merozoites can infect other red blood cells, repeating the cycle and causing malaria symptoms

Mosquito Stage

Mosquitoes become infected by consuming human erythrocytes containing merozoites
Within the mosquito, the merozoites develop into gametocytes
Gametocytes then fuse together to form zygotes
The zygotes undergoes sporozoite formation, creating sporozoites which are then injected into humans by the mosquito
The sporozoites then infect the liver, restarting the exerythrocytic cycle

Plasmodium sp. Transmission

The final host of Plasmodium is the female Anopheles mosquito
Humans are the intermediate host

Malaria

Malaria is caused by parasites of the genus Plasmodium that are transmitted by infected female Anopheles mosquitoes
Malaria is a serious illness that can be fatal
Symptoms include fever, chills, sweating, headache, muscle aches, and fatigue
Malaria is preventable and treatable

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz explores the characteristics and classifications of Sarcodina, including both free-living and parasitic amoebae such as Amoeba proteus and Entamoeba species. Learn about their unique movement, feeding habits, and ecological roles. Test your knowledge on these protozoans and their significance in different habitats.