Malaria: interrupt a vector’s role
הוצג| English | משמעות |
|---|---|
| protist/ˈprɒtɪst/ | פרוטיסט |
| disease vector/dɪˈziːz ˈvektə/ | מגש מחלה |
What would explain this observation?
- A mosquito can carry a pathogen without being the pathogen itself. Malaria prevention must address the vector as well as the parasite.
Build the model
- Malaria is caused by a protist 原生生物 pathogen.
- A mosquito is a vector: it transfers the pathogen between hosts and is involved in its life cycle.
- Malaria causes recurrent episodes of fever and can be fatal.
- Preventing mosquito bites, for example with suitable nets, and reducing mosquito breeding are specified methods of control.
- disease vector 传播媒介: An organism that carries a pathogen between hosts.
- protist: An organism in a diverse group that includes the malaria pathogen.
Which description correctly separates the two organisms?
רמת קושי 1/5 · 100 מטבעות + בונוס קטן בהשלמה הראשונה היום
The malaria pathogen is a protist (Plasmodium); the mosquito is the vector that carries it between people. The mosquito is not a bacterium, and a net blocks bites but kills nothing already inside a host.
Match each technical term to its precise meaning.
רמת קושי 2/5 · 140 מטבעות + בונוס קטן בהשלמה הראשונה היום
Use the definitions to distinguish related quantities and processes.
Choose evidence that can test it
- Distinguish organism roles carefully.
- The mosquito is an animal carrier, whereas the disease-causing organism is a protist.
- A net can reduce opportunities for a mosquito to bite a person; removing suitable breeding conditions can reduce the number of vectors.
- Neither measure should be described as directly killing every protist already inside an infected person.
In the lab: Build a paper model connecting infected host, mosquito and another host. Mark which link each proposed control interrupts. Analyse supplied fictional trap counts rather than breeding or handling mosquitoes. School field observations require teacher approval and should avoid exposure to bites or potentially contaminated water.
Which two habits make the investigation or model in this case more defensible?
רמת קושי 2/5 · 140 מטבעות + בונוס קטן בהשלמה הראשונה היום
Stating the conditions and assumptions lets others repeat the work exactly, and recording the supporting evidence lets them check the conclusion. Hiding disagreeing results removes the evidence that could challenge a wrong conclusion, and one measurement can never establish a wider claim.
Work from known quantities
- Known: fictional matched traps catch a mean of 40 mosquitoes before a breeding-site control and 26 after it.
- The decrease is 14; percentage decrease = 14/40×100 = 35%.
- Trap counts estimate vector abundance at those sites and times, not the number of human infections or an individual’s risk.
Your turn: Fictional trap counts fall from 50 to 35. Calculate percentage decrease.
Fictional trap counts fall from 50 to 35. Calculate percentage decrease.
רמת קושי 2/5 · 140 מטבעות + בונוס קטן בהשלמה הראשונה היום
The result is 30 %. Known: trap counts fall from 50 to 35. Decrease = 50 - 35 = 15. Percentage decrease = 15/50 x 100 = 30%. Trap counts estimate vector abundance, not human infections.
Check the conclusion and its limits
- Malaria is not caused by the mosquito itself or by a bacterium.
- Fewer vectors can reduce transmission opportunities, but a trap result alone does not demonstrate that malaria has been eradicated.
- Do not infer a safe travel or treatment decision from classroom model data.
Not true: The mosquito itself is the protist that causes malaria. The mosquito transmits the protist but does not cause the disease itself. Malaria is caused by Plasmodium, a protist - neither the insect nor a bacterium.
- Malaria is caused by a protist pathogen.
- Distinguish organism roles carefully.
- Watch for: malaria is not caused by the mosquito itself or by a bacterium.
The mosquito transmits the protist but does not cause the disease itself.
רמת קושי 1/5 · 100 מטבעות + בונוס קטן בהשלמה הראשונה היום
True. The mosquito transmits the protist but does not cause the disease itself. Malaria is caused by Plasmodium, a protist - neither the insect nor a bacterium.
An organism that carries a pathogen between hosts: write the technical term.
רמת קושי 1/5 · 100 מטבעות + בונוס קטן בהשלמה הראשונה היום
disease vector means An organism that carries a pathogen between hosts.