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<quiz display=simple>
<quiz display=simple>


{<span style="font-size:90%">Concerning schizonts which statements are correct? ('''select all true statements''')</br></br>
{<span style="font-size:90%">Concerning gametocytes which statements are correct? ('''select all true statements''')</br></br>
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- <span style="font-size:90%">The stage gives rise to gametocytes
- <span style="font-size:90%">The stage arises from schizonts
+ <span style="font-size:90%">Schizont release causes pyrexia
+ <span style="font-size:90%">In ''P.falciparum'' they have a "rod" shape
- <span style="font-size:90%">''P.malariae" typically forms 32 merozoites
- <span style="font-size:90%">Microgametocytes are the female form
+ <span style="font-size:90%">In ''P.falciparum'' they are rarely seen
- <span style="font-size:90%">Pigment generally forms a single clump
+ <span style="font-size:90%">The stage is morphologically variable
- <span style="font-size:90%">Red cell size is generally normal
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! colspan="1" | Explanation of correct answer (click "Expand")
! colspan="1" | Explanation of correct answer (click "Expand")
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|<span style="font-size:90%">''Short answer taken from section "Schizont Biology" (see the section for full details and links).</br></br>''Schizonts make repeated cycles of asexual development to generate muliple daughter "merozoites". The number of replication cycles differs between species: the typical number of merozoites formed differs between species with as few as 8 (in ''P.malariae'') up to a possible 32 (in ''P.vivax''). This stage may not be seen in blood films: the schizonts of ''P.falciparum'' adhere within the small vessels so is not seen in blood unless infection is very severe
|<span style="font-size:90%">''Short answer taken from section "Gametocyte Biology" (see the section for full details and links).</br></br>''A proportion of mature trophozoites give rise to the sexual gametocyte form, contained within ghost red cells (they have metabolised all haemoglobin in order to grow) - The red cell is therefore now simply a membrane that surrounds the parasite without any red colour, but generally retains any cytoplasmic dots typical of the species. Malaria pigment that represents the metabolised haem iron is prominent with different distributions that reflect the species. The appearance of gametocytes does vary according to species and this can aid morphological species identification with red cell appearances typical of the species, and (in the case of ''P.falciparum'' a distinctive straight or curved rod shape.</br>
</br></br>This progressive maturation means that they have a wide range of morphological forms (as shown in the diagram at the top of this page). When the merozoites are released this exposes the body to large amounts of free parasite antigens and can result is an immune response causing high fever and illness symptoms. In some cases the development of parasites is synchronous so that all schizonts mature and release their merozoites at the same time - although rarely seen now, this pattern of development may produce a pattern of remitting fever with a distinct periodicity depending on species: underlying the older descriptive terms tertian or quartan malaria.</span>
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|colspan="1" style = "font-size:90%; color:black|<span style="color:black>[[Biology_Quiz_A_Q5|Go to next question (5 of 5)]]</span>
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Latest revision as of 09:49, 21 March 2025

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Biology Quiz A Q4


On completion of their growth and maturation as trophozoites, a proportion of parasites mature into the sexual (gametocyte) stage that will be concluded within the gut of the mosquito. The stage may form male or female forms which have different size.

Concerning gametocytes which statements are correct? (select all true statements)

The stage arises from schizonts
In P.falciparum they have a "rod" shape
Microgametocytes are the female form
Pigment generally forms a single clump
Red cell size is generally normal


Explanation of correct answer (click "Expand")
Short answer taken from section "Gametocyte Biology" (see the section for full details and links).

A proportion of mature trophozoites give rise to the sexual gametocyte form, contained within ghost red cells (they have metabolised all haemoglobin in order to grow) - The red cell is therefore now simply a membrane that surrounds the parasite without any red colour, but generally retains any cytoplasmic dots typical of the species. Malaria pigment that represents the metabolised haem iron is prominent with different distributions that reflect the species. The appearance of gametocytes does vary according to species and this can aid morphological species identification with red cell appearances typical of the species, and (in the case of P.falciparum a distinctive straight or curved rod shape.
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