Transport In Plants Flashcards
(15 cards)
What is the phloem?
A living tissue which transports sugars made by photosynthesis from the leaves to the rest of the plant.
What is the xylem?
Dead cells which transport water and mineral ions from the roots to the steams and leaves.
What is osmosis?
The net movement of water through a partially permeable membrane from an area of high concentration to an area of low concentration.
How are root hair cells adapted for their function?
They have a finger-like projection which increases the surface area : volume so more nutrients and water can be absorbed.
What is the structure of a leaf?
Upper epidermis Palisade layer Spongy layer Lower epidermis Stomata controlled by guard cells
How are palisade cells adapted?
They contain many chloroplasts which allows a lot of photosynthesis to take place as they are the closest cells to the upper surface of the leaf.
How is the upper epidermis adapted for the exchange of materials?
It is transparent which allows light to go through the leaf for more photosynthesis to occur; it has a waxy cuticle, a waterproof layer which prevents water loss.
How is the spongy layer an adaptation for exchange?
The cells aren’t tightly packed which increases the rate at which gases can diffuse through the leaf.
What is the function of the guard cells?
They control the opening and closing of the stomata; this prevents too much water loss as water vapour is a waste product of respiration.
How are leaves adapted?
Their large surface area increases their ability to absorb light energy for use in photosynthesis; their thin shape allows short diffusion distances.
What is transpiration?
The loss of water vapour from the surface of plant leaves.
In which conditions will transpiration be the most rapid?
Hot
Dry
Windy
Bright
What does a potometer measure?
The rate of uptake of water by a plant.
What is the transpiration stream?
The constant movement of water through the xylem from the roots to the leaves, driven by the evaporation of water from the leaves.
How does wilting protect the plant from dying?
The leaves collapse and hang down, reducing the surface area for water loss by evaporation to occur.
