Biology: Cyst Development and Reproduction

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Questions and Answers

How do intestinal infections occur?

Through skin contact

Through breathing in contaminated air

Through eye contact

Through ingestion of contaminated food or drink (correct)

What is the mode of transmission of intestinal infections?

From person to person

Through touching infected animals

Through contaminated food and drink (correct)

Through insect bites

What is responsible for producing lesions in amoebiasis?

Cysts

Trophozoites (correct)

Sporozoites

Merozoites

What is the source of intestinal infections?

Contaminated food or drink Signup and view all the answers

What is the result of invasion of blood vessels in amoebiasis?

Secondary extra intestinal lesions Signup and view all the answers

How can intestinal infections be spread?

Through hand to mouth contact Signup and view all the answers

What is the primary source of intestinal infections?

Contaminated food and drink Signup and view all the answers

What type of lesions are produced by trophozoites in amoebiasis?

Primary intestinal lesions Signup and view all the answers

What happens when trophozoites invade blood vessels in amoebiasis?

The parasite spreads to other parts of the body Signup and view all the answers

What is the outcome of trophozoite invasion in amoebiasis?

Lesion formation in other parts of the body Signup and view all the answers

What happens to the effect of the parasite on the host over time?

It is toned down Signup and view all the answers

What happens to the host's tolerance to the parasite?

It increases Signup and view all the answers

What happens to the trophozoites in the lumen of the bowel?

They are transformed into pre-cyst forms Signup and view all the answers

What is the outcome for the parasite's life cycle in the trophozoite phase?

It is difficult to continue Signup and view all the answers

Where do the trophozoites come from before entering the lumen of the bowel?

Tissues Signup and view all the answers

What is the primary function of the cyst stage?

Quiescence and resistance Signup and view all the answers

How do trophozoites reproduce?

Through binary fission Signup and view all the answers

What is the characteristic of the mature cyst?

Multinucleated Signup and view all the answers

What is the characteristic of the nucleus in terms of chromatin arrangement?

Evenly arranged chromatin on the nuclear membrane Signup and view all the answers

What is the location of the karyosome in the nucleus?

Centrally located in the nucleus Signup and view all the answers

What is the outcome of the development of numerous trophozoites within the mature cyst?

Formation of multiple trophozoites Signup and view all the answers

What is the primary stage of infection?

Cyst Signup and view all the answers

What is the characteristic of motility in terms of direction?

Unidirectional Signup and view all the answers

What is the mechanism of motility?

Pseudopods Signup and view all the answers

What is the characteristic of motility in terms of speed?

Rapid and progressive Signup and view all the answers

Study Notes

Life Cycle of Amoeba

The cyst stage is quiescent, resistant, and infective.

Reproduction

Amoebas reproduce through binary fission, where the trophozoite splits.
Alternatively, numerous trophozoites develop within a mature multinucleated cyst.

Characteristics

Motility is rapid, progressive, and unidirectional, facilitated by pseudopods.
The nucleus is characterized by evenly arranged chromatin on the nuclear membrane and a small, compact, centrally located karyosome.

Infection and Transmission

Intestinal infections occur through the ingestion of a mature quadric nucleate infective cyst.
Contaminated food, drink, and hand-to-mouth contact can transmit the infection.

Pathogenesis

Trophozoites produce lesions in amoebiasis.
Invasion of blood vessels leads to secondary extra-intestinal lesions.

Host-Parasite Interaction

The parasite's effect on the host decreases over time, while host tolerance increases, making it difficult for the parasite to continue its life cycle in the trophozoite phase.

Cyst Formation

Some trophozoites from tissues enter the bowel lumen and transform into pre-cyst forms.

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Description

This quiz covers the quiescent, resistant, and infective stages of cyst development, including their reproduction through binary fission and the development of numerous trophozoites within the mature multinucleated cyst.