4.7 Transport systems in plants Flashcards
Photosynthesis word equation
carbon dioxide + water —> (sunlight) oxygen + glucose
Respiration word equation
oxygen + glucose —> carbon dioxide + water + energy
How does water get to the leaf for photosynthesis?
soil —> root hair cells —> xylem —> spongy layer —> palisade cells
How does water get leave the plant after respiration? (Osmosis/transpiration)
Palisade cell —> spongy layer —> stoma —> air surrounding leaf
How does CO2 enter the leaf for photosynthesis?
air —> stoma —> spongy layer —> palisade cell —> chloroplast
How does CO2 leave the leaf after respiration?
Chloroplasts —> palisade cell —> spongy layer —> stoma —> air
How does glucose move after being produced in photosynthesis?
Cytoplasm —> palisade cell —> phloem —> rest of plant or stored as starch
Describe how minerals get from soil to the plant
Soil —> root hair cells —> xylem —> rest of plant (via active transport)
Describe what is meant by translocation
The transport of dissolved material within a plant
Describe the features of xylem tissue
- cell wall made of lignin
- flow is upwards
- made of dead cells
- no cytoplasm
- cross-walls are absent
Describe the features of phloem tissue
- cell wall made of cellulose
- made of living cells
- also has companion cells
- flow is up and down
- has sieve plates
Explain how xylem tissue is formed
- xylem cells are alive when first formed
- lignin builds up spirals in cell walls
- cells die and form long hollow tubes
- tubes allow mineral ions to move easily through them
- spirals and rings of lignin make them very strong
- spirals also help support plant cell
Where is xylem and phloem found in woody plants like trees
Xylem makes up the bulk of wood, phloem found in a ring just underneath the bark
Why are young trees vulnerable to damage by animals?
If a complete ring of bark is eaten, transport in the phloem stops and the plant will die
Why do plants need mineral ions?
For production of proteins and other molecules within the cells
Why do plants need water?
For photosynthesis and to hold themselves upright
- when a plant has plenty of water, vacuole presses against cell walls
- pressure of the cytoplasm against the cell walls gives support for young plants and the structure of the leaves
- for young plants and soft-stem plants, water is the main method of support
Where does phloem transport sugar to?
- growing areas of the stem and roots where dissolved sugars needed to make new cells
- storage organs where it provides energy store for the winter
What do greenfly and other aphids do?
Push their sharp mouthparts into phloem and feed on sugary fluid. If too many of them attack a plant, they can killing it by taking all of its food
