Plant Organisation Flashcards
What is the main role of plant stems and roots? - Transport
For transporting substances throughout the plant
What do xylem tissues transport? - Transport
Water + mineral ions
What do phloem tissues transport? - Transport
Sugars and proteins dissolved in water
Name 2 ways plant leaves are adapted for photosynthesis - Plants
Large surface area - provides max absorption of light + CO2
Air spaces between cells - allows easier diffusion of gases
How is the palisade mesophyll adapted to absorb light? - Plants
Packed with chloroplasts
Cells arranged closely together
Towards the leaf’s upper surface to increase exposure to light
How is the spongy mesophyll adapted for gas exchange? - Plants
Loosely packed to increase space for gaseous exchange
Which direction do xylem transport substances? - Plants
Upwards
How are xylem tissues specialised? - Plants
They have no end walls, meaning there is a continuous stream of transport
Strengthened by a chemical called lignin, meaning the plant had support
Which direction do phloem tissues move substances? - Plants
Upwards and downwards
What is the movement of substances in phloem tissues called? - Plants
Translocation
Does the movement of substances in phloem cells require energy? - Plants
Yes, it’s done by active transport
Does the movement of substances in xylem cells require energy? - Plants
No, it is done by diffusion
What is transpiration? - Plants
The loss of water from plant leaves by evaporation through an open stomata
How is water lost through transpiration replaced? - Plants
Water is drawn from xylem cells to replace lost water
Name 3 purposes of water for plants - Plants
Used as water for photosynthesis
Transports mineral ions
Keeps the cell turgid
Cools the leaf as water evaporates