Plant infection, pests and mineral deficiency
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| mineral deficiency/ˈmɪnərəl dɪˈfɪʃənsi/ | 矿物质缺乏 | kuàng wù zhì quē fá |
| chlorosis/ˈklɔːrəʊsiz/ | 失绿症 | shī lǜ zhèng |
| magnesium ion/mæɡˈniːzɪəm ˈaɪɒn/ | 镁离子 | měi lí zi |
What would explain this observation?
- A yellow leaf may reflect infection or a shortage of a mineral. A symptom is a starting observation, so compare possible explanations before naming a cause.
- Start with a prediction. State the quantities or features you would compare, then decide what evidence could distinguish two explanations.
Build the model
- Plants can be damaged by pathogens such as TMV and rose black spot and by pests such as aphids. Aphids feed on plant material and can reduce growth. Mineral deficiency 矿物质缺乏 also damages a plant without being an infectious disease. Nitrate ions are needed to make amino acids and proteins; insufficient nitrate can cause stunted growth.
- chlorosis 失绿症: Yellowing associated with reduced chlorophyll; mineral deficiency: Insufficient supply of a needed mineral nutrient; magnesium ion 镁离子: A mineral ion needed by plants to make chlorophyll.
Which explanation matches nitrate deficiency?
Magnesium is needed for chlorophyll production. A shortage can cause chlorosis, or yellowing, which reduces effective light absorption for photosynthesis. Distinguish a pest, a pathogen and a nutrient shortage: an insect is not a mineral deficiency, and adding nitrate does not directly eliminate a virus.
Match each technical term to its precise meaning.
Use the definitions to distinguish related quantities and processes.
Choose evidence that can test it
- Magnesium is needed for chlorophyll production. A shortage can cause chlorosis, or yellowing, which reduces effective light absorption for photosynthesis. Distinguish a pest, a pathogen and a nutrient shortage: an insect is not a mineral deficiency, and adding nitrate does not directly eliminate a virus.
- Compare supplied photographs and teacher-prepared mineral-growth records. Keep plant species, light, water and observation time matched when interpreting a mineral comparison. Record alternative causes and the limits of the evidence. Do not grow or release pests or transfer infected plants as an unsupervised task.
Which two habits make the investigation or model in this case more defensible?
Compare supplied photographs and teacher-prepared mineral-growth records. Keep plant species, light, water and observation time matched when interpreting a mineral comparison. Record alternative causes and the limits of the evidence. Do not grow or release pests or transfer infected plants as an unsupervised task.
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: matched fictional seedlings grow 12 cm under a complete mineral treatment and 7.2 cm under a nitrate-limited treatment. Difference = 4.8 cm; decrease relative to the complete treatment = 40%. The mechanism links nitrate to protein production, but the numerical difference is specific to the stated model.
Model seedling height falls from 15 to 9 cm. Calculate percentage decrease. Use the same sequence: known quantities → model → relation → substitution → unit and interpretation.
Model seedling height falls from 15 to 9 cm. Calculate percentage decrease.
The result is 40 %. Known: matched fictional seedlings grow 12 cm under a complete mineral treatment and 7.2 cm under a nitrate-limited treatment. Difference = 4.8 cm; decrease relative to the complete treatment = 40%. The mechanism links nitrate to protein production, but the numerical difference is specific to the stated model.
Check the conclusion and its limits
- Chlorosis describes yellowing rather than proving a single cause. Nitrate supports protein synthesis, while magnesium supports chlorophyll production; swapping these explanations loses the mechanism. Higher-only disease-identification methods are taught separately from this both-tier plant content.
- Return to the original observation. Explain what the result supports, which conditions it assumes, and one way to test a competing explanation.
Every yellow leaf proves a fungal infection. This claim is false: Chlorosis describes yellowing rather than proving a single cause. Nitrate supports protein synthesis, while magnesium supports chlorophyll production; swapping these explanations loses the mechanism. Higher-only disease-identification methods are taught separately from this both-tier plant content.
Plant infection, pests and mineral deficiency: Magnesium is needed for chlorophyll production. A shortage can cause chlorosis, or yellowing, which reduces effective light absorption for photosynthesis. Distinguish a pest, a pathogen and a nutrient shortage: an insect is not a mineral deficiency, and adding nitrate does not directly eliminate a virus.
Every yellow leaf proves a fungal infection.
Chlorosis describes yellowing rather than proving a single cause. Nitrate supports protein synthesis, while magnesium supports chlorophyll production; swapping these explanations loses the mechanism. Higher-only disease-identification methods are taught separately from this both-tier plant content.
Yellowing associated with reduced chlorophyll: write the technical term.
chlorosis means Yellowing associated with reduced chlorophyll.