Specialized cells: connect a feature to the task
| English | 中文 | Pinyin |
|---|---|---|
| specialized cell/ˈspeʃəlaɪzd sel/ | 特化细胞 | tè huà xì bāo |
| root hair cell/ruːt heə sel/ | 根毛细胞 | gēn máo xì bāo |
What would explain this observation?
- A long root hair increases contact with soil, while a long nerve cell can carry information over a distance. Shape is useful when its effect on function is explained.
- Start with a prediction. State the quantities or features you would compare, then decide what evidence could distinguish two explanations.
Build the model
- A sperm cell has a tail for movement, mitochondria providing energy through respiration and an acrosome containing enzymes that help entry into an egg. A nerve cell has a long extension carrying impulses and branches connecting with other cells. Muscle cells contain contractile structures and many mitochondria for the energy demand of contraction.
- specialized cell 特化细胞: A cell with structures suited to a particular function; root hair cell 根毛细胞: A root-surface cell with a projection that increases absorbing area.
Which explanation correctly links a root-hair feature with its function?
A root hair cell has a long projection increasing surface area for absorption. Xylem vessels are dead hollow cells joined into tubes, with strengthened lignified walls carrying water and supporting the plant. Phloem transports dissolved sugars through living tissue; its conducting cells work with companion cells. GCSE explanations should link each named feature to its role rather than give an unsupported list.
Match each technical term to its precise meaning.
Use the definitions to distinguish related quantities and processes.
Choose evidence that can test it
- A root hair cell has a long projection increasing surface area for absorption. Xylem vessels are dead hollow cells joined into tubes, with strengthened lignified walls carrying water and supporting the plant. Phloem transports dissolved sugars through living tissue; its conducting cells work with companion cells. GCSE explanations should link each named feature to its role rather than give an unsupported list.
- Compare labelled teacher-provided cell diagrams at stated scales. Use the pattern feature → effect → function. For unfamiliar cells, read the supplied information and reason from it; do not assume every specialized cell has lost its nucleus or contains a tail.
Which two habits make the investigation or model in this case more defensible?
Compare labelled teacher-provided cell diagrams at stated scales. Use the pattern feature → effect → function. For unfamiliar cells, read the supplied information and reason from it; do not assume every specialized cell has lost its nucleus or contains a tail.
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 root hair has an absorbing surface of 1.8 square units instead of 0.6 for a rounded model cell. The surface ratio is 1.8/0.6 = 3. This can increase exchange capacity under the same conditions, but transport also depends on concentration, membrane processes and available energy.
Absorbing surface changes from 0.8 to 2.4 square units. Calculate the surface-area ratio. Use the same sequence: known quantities → model → relation → substitution → unit and interpretation.
Absorbing surface changes from 0.8 to 2.4 square units. Calculate the surface-area ratio.
The result is 3 . Known: a model root hair has an absorbing surface of 1.8 square units instead of 0.6 for a rounded model cell. The surface ratio is 1.8/0.6 = 3. This can increase exchange capacity under the same conditions, but transport also depends on concentration, membrane processes and available energy.
Check the conclusion and its limits
- More mitochondria does not mean mitochondria themselves contract or propel the cell. Xylem and phloem are different tissues and do not carry the same substances by the same mechanism. A cell adaptation is explained in the context of its task.
- Return to the original observation. Explain what the result supports, which conditions it assumes, and one way to test a competing explanation.
Every specialized cell has the same sub-cellular structures. This claim is false: More mitochondria does not mean mitochondria themselves contract or propel the cell. Xylem and phloem are different tissues and do not carry the same substances by the same mechanism. A cell adaptation is explained in the context of its task.
Specialized cells: connect a feature to the task: A root hair cell has a long projection increasing surface area for absorption. Xylem vessels are dead hollow cells joined into tubes, with strengthened lignified walls carrying water and supporting the plant. Phloem transports dissolved sugars through living tissue; its conducting cells work with companion cells. GCSE explanations should link each named feature to its role rather than give an unsupported list.
Every specialized cell has the same sub-cellular structures.
More mitochondria does not mean mitochondria themselves contract or propel the cell. Xylem and phloem are different tissues and do not carry the same substances by the same mechanism. A cell adaptation is explained in the context of its task.
A cell with structures suited to a particular function: write the technical term.
specialized cell means A cell with structures suited to a particular function.