SB6 - Plant structures and their functions Flashcards
What is the word equation for photosynthesis?
water + carbon dioxide -> glucose + oxygen
from what sugar do plants make starch?
glucose
what do plants use starch for?
to store for energy
what process do plants use to release energy as they need it?
aerobic respiration
what is biomass?
the materials in an organism
why do animals need plant biomass?
animals cannot produce their own food so have to consume producers (organisms that produce their own food)
how does a large surface area help photosynthesis?
provides large area for light to be absorbed
how does chlorophyll help photosynthesis?
traps energy transferred by light
how do stomata help photosynthesis?
allows gas exchange/carbon dioxide to get into the plant as it needs it.
what does photosynthesis need that is transferred by light?
energy
what are the 3 factors affecting the rate of photosynthesis?
light intensity, temperature and concentration of carbon dioxide
why does photosynthesis work better at higher temperatures?
photosynthesis is a process that uses enzymes, which work better at higher temperatures
what gas would you expect to be in the bubbles produced by a photosynthesis experiment?
oxygen
what is a limiting factor?
a single factor which, in short supply, can limit the rate of a process such as photosynthesis
what part of a root hair cell could be described as a semi-permeable membrane?
cell membrane
by what process does water enter a root hair cell?
osmosis
how does the shape of a root hair cell help osmosis occur?
it has a large surface area which speeds up water absorption
which cells are responsible for carrying water out of the root and up the plant?
xylem
what is the ion that is important for producing proteins?
nitrate ions
why do nitrate ions have to be moved into a root hair by active transport?
nitrate ions are in greater concentration in the cell than in the soil so the cells have to use energy to transport the ions against the concentration gradient
what is transported by transpiration?
water and dissolved minerals
what is sucrose transported by?
translocation
what cells are used to pump sucrose in phloem tissue?
companion cells
are companion cells living or dead?
living
what process drives translocation?
active transport
what are two substances found in xylem that help to support the plant?
lignin and cellulose
what is the equipment used to measure the rate of transpiration?
a potometer
what is the relationship between wind speed and the rate of transpiration?
the higher the wind speed, the faster the rate of transpiration
why is the rate of transpiration faster when the wind speed is higher?
the faster the water molecules are being moves away from the plant, the less time there is for the concentration gradient to be reduced.
give a factor that causes a decrease in transpiration when the factor increases
humidity
what causes water to move up the xylem on a sunny day?
the water evaporates from the leaves, pulling water up the xylem
state a major sugar transported in translocation
sucrose
how is a large surface area a plant adaption?
to collect enough light to aid photosynthesis
how does carbon dioxide enter a leaf for photosynthesis?
it diffuses through the stomata
why are the leaves being thin a good adaption for plants?
so that the diffusion path is small
what causes space for air in the spongy mesophyll layer of a plant?
the cells are irregularly shaped to cause them to not fit exactly together, creating space for gases.
what do epidermis cells do?
they form the outer layers of a leaf, holding them together and protecting the cells inside.
why are epidermis cells transparent?
to allow light to pass through them
why do broad-leaved trees loose their leaves in the winter?
to prevent water loss when they are frozen
why do conifers leaves have a small surface area and a thick cuticle?
so that they are more wind resistant and do not catch snow
why do conifers have their stomata in small pits?
so that water vapour can collect where it is not exposed to air movement
what 3 gasses are exchanged through a leaf?
carbon dioxide, water vapour, oxygen
why are stomata open during the day?
so that carbon dioxide can enter the leaf while there is light available for photosynthesis
why do spongy cells create air spaces in a leaf?
to allow carbon dioxide to be stored for photosynthesis
