Measles, HIV and tobacco mosaic virus
| English | 中文 | Pinyin |
|---|---|---|
| antiretroviral drug/ˌæntɪˌretrəʊˈvaɪərəl drʌɡ/ | 抗逆转录病毒药物 | kàng nì zhuǎn lù bìng dú yào wù |
| tobacco mosaic virus/təˈbækəʊ məˈseɪɪk ˈvaɪrəs/ | 烟草花叶病毒 | yān cǎo huā yè bìng dú |
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.
- Start with a prediction. State the quantities or features you would compare, then decide what evidence could distinguish two explanations.
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?
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.
Match each technical term to its precise meaning.
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.
- 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?
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.
Work from known quantities
- State the known values and their units. Choose the relation because its assumptions fit this case, then rearrange before substitution.
- 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.
Model photosynthetic output falls from 60 to 45 units. Calculate percentage decrease. Use the same sequence: known quantities → model → relation → substitution → unit and interpretation.
Model photosynthetic output falls from 60 to 45 units. Calculate percentage decrease.
The result is 25 %. 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.
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.
- Return to the original observation. Explain what the result supports, which conditions it assumes, and one way to test a competing explanation.
HIV and AIDS always mean the same stage of infection. This claim is false: 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.
Measles, HIV and tobacco mosaic virus: 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.
HIV and AIDS always mean the same stage of infection.
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.
A drug used to control a retroviral infection such as HIV: write the technical term.
antiretroviral drug means A drug used to control a retroviral infection such as HIV.