sb6 Flashcards
from this data, which compost is best for a pot containing strawberry plants during a hot summer?
the compost with the highest percentage of water retained because in higher temps, there is the highest volume of water loss in plants which causes a faster rate of transpiration
why does reducing the water content of strawberries preserve them?
it reduces the number of microorganisms that can reproduce and because of this it reduces the decay process and preserves the food
what is a reason for sterilising?
to kill unwanted microorganisms
what is the trend for the light intensity cpac? refrence the data
as the light intensity decreases, the rate of photosynthesis decreases, after 20 cm, the light intensity seems to have little effect on the rate of photosynthesis
how do you measure light intensity?
using a lux metre
what is a better method for measuring the volume of gas released in a experiment than counting the bubbles?
collect the gas produced in a syringe to reduce errors when counting the bubbles because the bubbles can be different sizes
what is the level of gas produced when light intensity is 0.0001?
the volume of gas produced would be less than four bubbles because light is needed for photosynthesis
what is positive gravitropism?
auxin diffuses/moves to the bottom side of the root which inhibits the elongation of root cells, making the roots grow downwards
what are the benefits for roots growing downwards?
make the plant stable, access to mineral ions
there is a plant shoot experiment with a control, a black cap on the tip and block of jelly between the tip and shoot. explain the results.
plant with black cap didnt curve, plant with jelly did curve, the jelly allows auxin to diffuse and cause feel elongation, the black cap does not let the light shine on the tip so the auxin will not diffuse
what is an experiment that shows that auxin is found in the tip?
remove the tip from one of the plant shoots and leave the other, measure the changes in growth and direction
what is a quadrat?
measures the distribution of plants on the bark of a tree
why is a plastic bag placed around a plant pot during an investigation?
to prevent evaporation from the soil, make sure that the method is a fair test
why would there be an increase in the mass of a courgettes in a sugar solution at 0.2 mol/dm^3?
osmosis moves water form an area of high conc to an area of low conc through the cell membrane. there is a higher conc of water outside the courgette.
how does water moves into a plant?
by osmosis down a concentration gradient through a partially permeable membrane
