B9 Transpiration new Flashcards
Name the organ shown in the diagram
Leaf
Name the tissue labelled C
Spongy mesophyll
Name the tissue labelled B
Palisade mesophyll
Name the tissue labelled A
Upper epidermis
The tubes that transport water and mineral ions are called …
Xylem
How is the xylem adapted for its function?
Dead cells
Form continuous hollow tube from root to shoot
Strengthened and waterproofed with lignin
Whch plant organ is used to absorb water and mineral ions?
Root
Name the process used to absorb water from the soil.
Osmosis
Name the process used to absorb mineral ions from the soil
Active transport
Name the specilised cells used to increase the surface area
of the root in contact with the soil.
Root hair cells
How are the root hair cells adapted for their function?
Large surface area
Lots of mitochondria to release energy for active transport
What is transpiration?
Transpiration is the evaporation of water vapour and its diffusion through the stomata
How does transpiration move water up a plant?
Water evaporates from the mesophyll cells and diffuses out of the stomata
Water is pulled out of the xylem vessel to replace the lost water.
Water molecules in the xylem stick to each other and are pulled up the xylem.
Water is absorbed by the roots and travels to the xylem vessel.
Explain how an increase in temperature affects the rate of transpiration
Increasing temperature increases the rate of transpiration.
More water converted into water vapour (evaporation)
Faster diffusion through stomata as molecules moving faster.
Explain how humidity affects the rate of transpiration
Increasing humidity decreases the rate of transpiration.
High concentration of water vapour in the atmosphere around the leaf reduces the concentration gradient and causes less water to leave the leaf.
Explain how wind speed affects the rate of transpiration
Increasing wind speed/ air movement increases the rate of transpiration
Increase air movement reduces the water vapour concentration outside the leaf. The concentration gradient is reduced and less water diffuses out of the leaf.
Explain how light intensity affects the rate of transpiration
Increasing light intensity increases the rate of transpiration
More stomata open to allow carbon dioxide into the leaf for photosynthesis.
More water vapour can escape from the leaf.
Name the organs of a plant involved in the transport of
substances around the plant
Root, stem and leaves
Name the cells that surround the stomata and what is their function?
Guard cells
Open the stomata during the day to allow gas exchange for photosynthesis.
Close the stomata at night to reduce water loss. and close the stomata
In which direction does water travel in a plant?
From root to shoot
Name the cells shown on the picture
Guard cells
