Parts of the plant Flashcards
What is the xylem
Specialised tissue used to transport water up the stem of a plant and into the leaves. Dead cells
Xylem adaptations
The end walls of the dead cells are broken to allow water to move through
Lignin strengthens the cell walls of the xylem cells
What is transpiration
It transports water and the minerals dissolved in it through the plant. Water only moves in one direction: from the root to the leaves
How does transpiration work
Root hair cells absorb water via osmosis and Minerals are taken up by active transport. After they are absorbed by the root hair cells, they are transported in xylem vessels up the stem and into the leaves. Once it reaches the leaves, majority of the water evaporates through the open stomata. This is known as transpiration.
Factors affecting Transpiration
Light intensity- increases transpiration
Temperature- increases transpiration
Humidity-decreases transpiration
Airflow- increases transpiration
What is used to calculate transpiration
A potometer
What are the stomata
Gaps in the lower epidermis of leaves that facilitate diffusion of gases in and out of the leaf. Guard cells have lost water when the stomata are closed but have gained water when open.
The state of stomata
When water is abundant, the stomata is open, allowing photosynthesis to happen. When water is scarce, the stomata close trying to save water. At night the stomata are closed as photosynthesis doesn’t need carbon dioxide in the dark
What is phloem
Specialised tissue used to transport food products to parts of the plant where they are needed. Living cells
What happens in the phloem
Translocation happens in the phloem and the phloem is bidirectional
What is translocation
The process by which food produced in photosynthesis is transported from the leaves to growing regions of the plant
