Plant infection, pests and mineral deficiency
הוצג| English | משמעות |
|---|---|
| mineral deficiency/ˈmɪnərəl dɪˈfɪʃənsi/ | חוסר מינרלים |
| chlorosis/ˈklɔːrəʊsiz/ | כלורוזיס (הצהבת עלים) |
| magnesium ion/mæɡˈniːzɪəm ˈaɪɒn/ | יון מגנזיום |
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.
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 缺绿: 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?
רמת קושי 1/5 · 100 מטבעות + בונוס קטן בהשלמה הראשונה היום
Nitrate provides the nitrogen plants need to build amino acids and therefore proteins; with less nitrate, protein production and growth are restricted. Nitrate is a mineral ion, not a virus, and cannot create magnesium.
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
- 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.
In the lab: 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?
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: 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.
Your turn: Model seedling height falls from 15 to 9 cm. Calculate percentage decrease.
Model seedling height falls from 15 to 9 cm. Calculate percentage decrease.
רמת קושי 2/5 · 140 מטבעות + בונוס קטן בהשלמה הראשונה היום
The result is 40 %. Known: height falls from 15 to 9 cm. Decrease = 15 - 9 = 6 cm. Percentage decrease = 6/15 x 100 = 40%. The figure is specific to this 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.
Not true: Every yellow leaf proves a fungal infection. Yellowing (chlorosis) has several causes - magnesium deficiency, nitrate deficiency, disease. A yellow leaf is a symptom needing confirmation, not proof of fungal infection.
- Plants can be damaged by pathogens such as TMV and rose black spot and by pests such as aphids.
- Magnesium is needed for chlorophyll production.
- Watch for: chlorosis describes yellowing rather than proving a single cause.
Every yellow leaf proves a fungal infection.
רמת קושי 1/5 · 100 מטבעות + בונוס קטן בהשלמה הראשונה היום
Yellowing (chlorosis) has several causes - magnesium deficiency, nitrate deficiency, disease. A yellow leaf is a symptom needing confirmation, not proof of fungal infection.
Yellowing associated with reduced chlorophyll: write the technical term.
רמת קושי 1/5 · 100 מטבעות + בונוס קטן בהשלמה הראשונה היום
chlorosis means Yellowing associated with reduced chlorophyll.