bio test 1 Flashcards
What do plants need to survive
- Water
- CO2
- Sunlight (energy)
Word equation for photosynthesis
water + carbon dioxide → glucose + oxygen.
Balanced symbol equation for photosynthesis
6CO2 + 6H2O → C6H12O6 + 6O2
What are endothermic reactions
any chemical reaction that absorbs energy from its environment.
Function of palisade mesophyll
Where photosynthesis it absorb a large amount of light for photosynthesis.
Function of spongy mesophyll
facilitates the exchange of gases
Function of xylem
transport water and dissolved minerals up the stem
Epidermis
covers and protects the plants surface from infection and water loss.
Meristem
Meristems make unspecialised cells that have the potential to become any type of specialised cell.
Adaptions of a leaf (5)
- Broad leaves - maximise surface area.
- Thin leaves - short diffusion distance.
- Chlorophyll present - trap light energy.
- Veins - transport water to leaves via xylem, remove photosynthesis products via phloem.
- Air spaces - allow Carbon dioxide, to enter and Oxygen, to leave
Guard cells
control opening of stomata for gaseous exchange and prevent water loss.
What does the limiting factor of photosynthesis do
slows down the rate of a photosynthesis
What are the limiting factors of photosynthesis
light intensity
CO2 concentration
temperature
Translocation
- the transport of sucrose and amino acids in phloem
Transpiration
- transport of mineral
function of stomata
Controls the exchange of the gases by closing and opening the pores in the leaves.
function of phloem
transports sucrose (sugar) and other nutrients around the plant
which enviromental change would cause an increase in the rate of transpiration
increase in temperature
suggest one possible cause of the anomalous result
scale of value was misread
how could the student deal with an anomalous result
not use it on the calculation
what’s the independent variable
Change
what’s the control variable
Keep the same
what’s the dependent variable
Measure
why does the rate of photosynthesis decrease as the temperature increases
the enzymes denatures
Where does photosynthesis take place?
Within chloroplasts in leaf palisade cells. They contain chlorophyll, a pigment which absorbs light energy.
Is photosynthesis an endothermic or exothermic reaction, and why?
Endothermic - energy is transferred from the environment to chloroplasts by light.
How can you show that a plant gives off oxygen during photosynthesis?
Using a water plant (eg. Elodea), collect gas bubbles produced during photosynthesis. The gas will relight a glowing splint as it contains oxygen
How does temperature affect the rate of photosynthesis?
Increasing the temperature increases the rate of photosynthesis as the kinetic energy of particles is increased. The rate decreases past a certain temperature as enzymes become denatured.
How does light intensity affect the rate of photosynthesis?
Increasing the light intensity increases the rate of photosynthesis until another factor becomes limiting.
How does carbon dioxide concentration affect the rate of photosynthesis?
Increasing the carbon dioxide concentration increases the rate of photosynthesis (until another factor becomes limiting) as CO, is required to make glucose.
How does the amount of chlorophyll affect the rate of photosynthesis?
Decreasing the amount of chlorophyll (eg. due to a lack of magnesium) decreases the rate of photosynthesis as chlorophyll is required to absorb light energy.
What is a limiting factor?
An environmental factor which can restrict the rate of photosynthesis eg.
light intensity.
How can farmers use their knowledge of limiting factors to increase their profits?
They can control temperature, light intensity and CO2 concentration to achieve the fastest possible rate of photosynthesis
State 5 uses of the glucose produced during photosynthesis
- Respiration
- Starch for storage
- Cellulose for strength
- Amino acid and protein synthesis (combined with nitrates)
- Lipids for energy storage in seeds
where does the energy for photosynthesis comes from
respiration
