Leaves and Photosynthesis Flashcards
2 major functions of leaves
photosynthesis and transpiration/gas exchange
where are stems attached to the stem
at the node
dicot leaves are attached via the _______
petiole
compound leaves consist of multiple ________
leaflets
How are monocot leaves attached
the sheath
where are leaf primordia generated
near the shoot apical meristem
leaf veins
made of xylem and phloem
responsible for carrying water and other material to and from the leaf
why are veins arranged how they are
Organized based on how leaves grow. Ex: Grass leaves grow up, so the veins are adapted to grow long and parallel
What does the dermal tissue do (epidermis, guard cells)
protection
limit water loss
facilitate gas exchange with the environment (stomata)
What does the vascular tissue do (xylem and phloem)
supply water and nutrients
export of photosynthate
what does the ground tissue do
photosynthesis
site of gas exchange
storage
what type of cells is mesophyll made of?
parenchyma cells
what does the mesophyll do
capture light energy and use it to synthesize carbohydrates
Characteristics of the mesophyll cell wall and why it is that way
thin cell wall that are generally well hydrated
help facilitate exchange of CO2 and O2
Characteristics of palisade mesophyll
right angles to adaxial surface of the leaf (the top
long, rectangular, tightly packed, thin
Characteristics of spongy mesophyll
irregularly spaced and sized
many air spaces
how does the guard cell regulate the rate of water loss
by changing the size of the central pore
Why is the opening and closing of the stomata considered a balancing act?
at times that photosynthetic activity is highest (high light and temp) means need for more CO2, but is also when water loss is the greatest
why is the rate of water loss greater than CO2 uptake
difference in water vapor concentration between the air and sub-stomatal space is greater that the difference of CO2 inside and outside the leaf
types of mesophyll
palisade and spongy mesophyll
2 different reactions of photosynthesis
light-dependent and light-independent
what does the light-dependent reaction do
electron transfer
what does the light-independent reaction do
enzymatic reactions
what will intact chloroplasts do compared to isolated thylakoids
Intact chloroplasts - will absorb light energy and synthesize carbohydrates
Isolated thylakoids - will generate O2 and ATP, but no sugars
