Topic Test- Plants(Diseases, Defences, Photosynthesis) Flashcards
What is a control variable?
the thing that doesn’t change.
use key terminology like volume and mass NOT amount
What is an independent variable?
the thing that changes
What is a dependent variable?
the thing you measure
What are the physical barriers?
waxy cuticle
cellulose cell wall
bark on the tree
leaf fall
what is the function of the waxy cuticle?
keeps the plant tough so acts as a physical barrier
what does the cellulose cell wall do?
keeps the plant strong
what does bark on the tree do?
gives strength and toughness to a tree to prevent anything entering
what is a chemical barrier?
releasing antibacterial chemicals to kill any diseases
how do plants deter herbivores from eating them as an act of defence?
- changes colour to appear poisonous
- droops with contact to appear dead or unhealthy
- having thorns
- having hairy stems
What is a specialised cell?
A cell that he adapted to a specific function
what are the main 4 plant organs?
- roots
- stem
- leaf
- flower
what is the function of epidermal tissue?
covers the surface of the plant to protect them
how has the epidermal tissues adapted to its function?
they often secrete a waterproof waxy substance to keep the surface of the leaf protected
what is the function of the palisade mesophyll?
to carry out photosynthesis
how has the palisade mesophyll adapted to its function?
by having a lot of chloroplasts
what is the function of spongey mesophyll?
to diffuse gasses and to perform some photosynthesis
how has spongey mesophyll adapted to its function?
- contains some chloroplasts to aid photosynthesis
- large surface area and large air spaces to aid the gas exchange
what is the function of xylem?
to carry water and dissolved minerals through the roots to the leaf
how has the xylem adapted to its function?
they are dead tissue so it hollows out allowing water to travel faster through it
what is the function of phloem?
to carry dissolved food up through the roots to the leaf
how has phloem adapted to its function?
the cell walls break down to form special sieve plates which allows dissolved food to move more freely
what is translocation?
the movement of materials from leaves to other tissues throughout the plant
What does the stomata do?
allows gasses to come in and out the cell (oxygen and CO2)
What do guard cells do?
control the opening and closing of stomata
