SB6 - Plant structures & their functions Flashcards
What type of reaction is photosynthesis?
Endothermic
How is photosynthesis an endothermic reaction?
Energy is transferred from the environment to the chloroplasts by light
What is photosynthesis?
The process by which plants manufacture carbohydrates from raw materials using energy from light
What’s the word equation for photosynthesis?
What’s the chemical equation for photosynthesis?
In which part of the plant does photosynthesis occur?
Chloroplasts
—> Chlorophyll
What are the main producers of food?
Plants & Algae
What are the primary producers of biomass in all food webs & chains?
Plants & Algae
What factors affect the rate of photosynthesis?
- Temperature
- Light intensity
- Co2 concentration
Which axis does the limiting factors go on when we use graphs?
X - axis
What are root hair cells specialised to do?
Specialised to take up water by osmosis and mineral ions by active transport from the soil as they are found in the tips of roots
List how root hair cells are specialised
- Large surface area
- Lots of mitochondria
- Large, permanent vacuole
How does having a Large surface area help root hair cells?
More water can move in
How does having a Lots of mitochondria help root hair cells?
Provides energy for the active transport of mineral ions into root hair cell
How does having a Large, permanent vacuole help root hair cells?
Affects the speed of movement of water from the soil to the cell
List how xylem cells are specialised
- Dead cells become lignified
- Lignin is deposited in spirals
How does having dead cells become lignified help xylem cells?
Lignin is deposited which causes the cells to die
—> They become hollow & join end-to-end so water and mineral ions can move through
How does Lignin is deposited in spirals help xylem cells?
Helps the cells withstand the pressure from the movement of water
What are xylem cells specialised to do?
Specialised to transport water and mineral ions up the plant from the roots to the shoots
What are Phloem cells specialised to do?
Specialised to carry the products of photosynthesis (food) to all parts of the plants
List how phloem cells are specialised
- Cell walls form sieve plates
- Energy is supplied by mitochondria of the companion cells
How does cell walls form sieve plates help phloem cells?
Allows the movement of substances from cell to cell
How does energy is supplied by mitochondria of the companion cells help phloem cells?
These cells use this energy to transport sucrose (the sugar that plants use) around the plant
What is transpiration?
The loss of water of water vapour from the leaves and stems of the plant
What is the purpose of guard cells
Close and open stomata
Describe the structure of guard cells
- They are kidney shaped
- They have thin outer walls and thick inner walls
How does stomatas being located at the bottom of the leaf aid gas exchange?
Allows gases to be exchanged whilst minimising water loss by evaporation as the lower surface is shaded and cooler
What is translocation?
The movement of food substances (such as sucrose) made in the leaves up or down the phloem, for use immediately or storage
Where does translocation occur?
Phloem
What is a source?
The places where the substance is made
What is a sink?
The places where the substance used or stored
What does the location of the sources and sinks depend on?
The season
