Measles, HIV and tobacco mosaic virus
הוצג| English | משמעות |
|---|---|
| antiretroviral drug/ˌæntɪˌretrəʊˈvaɪərəl drʌɡ/ | תרופת אנטי-רטרווירוס |
| tobacco mosaic virus/təˈbækəʊ məˈseɪɪk ˈvaɪrəs/ | ויירוס מוזאיקה של טבק |
What would explain this observation?
- A red rash, a weakened immune system and a discoloured leaf are different outcomes of viral disease. Their transmission routes and effects must remain separate.
Build the model
- Measles causes fever and a red skin rash and can have serious, sometimes fatal complications.
- It spreads by inhaled droplets from coughs and sneezes; vaccination is the specified preventive measure.
- HIV can initially cause a flu-like illness.
- Without successful antiretroviral control it damages immune cells; late-stage infection, AIDS, leaves the body less able to deal with other infections or cancers.
- antiretroviral drug 抗逆转录病毒药物: A drug used to control a retroviral infection such as HIV.
- tobacco mosaic virus 烟草花叶病毒: A plant virus causing mosaic leaf discolouration and reduced photosynthesis.
Why can TMV reduce plant growth?
רמת קושי 1/5 · 100 מטבעות + בונוס קטן בהשלמה הראשונה היום
TMV discolours leaves into a mosaic pattern; the lost green area photosynthesises less, so less glucose is produced and growth slows. The virus does not transform cells into bacteria and causes no human disease.
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
- HIV spreads through sexual contact or exchange of body fluids such as blood, including shared needles.
- Tobacco mosaic virus, TMV, causes a mosaic pattern of leaf discolouration.
- Less effective photosynthetic tissue means less glucose production, reducing plant growth.
- A symptom describes an effect; it is not itself the mechanism of transmission.
In the lab: Compare supplied disease fact cards in a table with host, symptoms, route and control. Use anonymized fictional data only. For a plant model, compare leaf photographs and stated photosynthesis measurements under the same light and temperature. Do not infer a medical diagnosis from a classroom image or symptom list.
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: a model healthy leaf produces 80 relative units of glucose in the stated interval and an infected leaf produces 52 under matched conditions.
- The decrease is 28 units; percentage decrease = 28/80×100 = 35%.
- This supports lower photosynthetic output in that model, not a universal TMV reduction.
Your turn: Model photosynthetic output falls from 60 to 45 units. Calculate percentage decrease.
Model photosynthetic output falls from 60 to 45 units. Calculate percentage decrease.
רמת קושי 2/5 · 140 מטבעות + בונוס קטן בהשלמה הראשונה היום
The result is 25 %. Known: output falls from 60 to 45 units. Decrease = 60 - 45 = 15 units. Percentage decrease = 15/60 x 100 = 25%. This model result does not set a universal TMV reduction.
Check the conclusion and its limits
- HIV infection and AIDS are not interchangeable labels for every stage.
- Antibiotics do not kill these viruses.
- TMV affects plants rather than causing the human symptoms described for measles or HIV.
- Classroom facts do not prescribe a treatment or vaccination schedule.
Not true: HIV and AIDS always mean the same stage of infection. HIV is the virus infection; AIDS is the later stage when the immune system is badly damaged and secondary illnesses appear. A person can carry HIV for years without AIDS.
- Measles causes fever and a red skin rash and can have serious, sometimes fatal complications.
- HIV spreads through sexual contact or exchange of body fluids such as blood, including shared needles.
- Watch for: HIV infection and AIDS are not interchangeable labels for every stage.
HIV and AIDS always mean the same stage of infection.
רמת קושי 1/5 · 100 מטבעות + בונוס קטן בהשלמה הראשונה היום
HIV is the virus infection; AIDS is the later stage when the immune system is badly damaged and secondary illnesses appear. A person can carry HIV for years without AIDS.
A drug used to control a retroviral infection such as HIV: write the technical term.
רמת קושי 1/5 · 100 מטבעות + בונוס קטן בהשלמה הראשונה היום
antiretroviral drug means A drug used to control a retroviral infection such as HIV.