Page 19 - 新思维科学学生用书7 样章
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1 Cells
Some specialised plant cells
Plants also contain specialised cells.
Here are two examples.
Root hair cells are found on the outside cell wall nucleus
of plant roots.
Their function is to absorb (soak up) cell membrane
water from the soil.
cytoplasm
Each cell has a long, thin extension that
allows water to move easily from the soil large vacuole
into the cell. with cell sap
A root hair cell
Palisade cells are found in the leaves of cell wall
plants. Their function is to make food
by photosynthesis. cell membrane
They have a lot of chloroplasts containing
chlorophyll. mitochondrion
The chlorophyll absorbs energy from
sunlight, which is used to help the plant cytoplasm
make food.
chloroplast
nucleus
A palisade cell
Questions
3 Suggest why root hair cells do not contain chloroplasts.
4 Water moves through several parts of the root hair cell, as it goes from the soil into the sap
vacuole. List these parts, in order.
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