use of bio resources (food production: crop plants, microorganisms, fish farming)

microorgs and fish farming not done yet

greenhouse conditions that can be manipulated and how that helps crop production (4)

• Artificial heating (enzymes controlling photosynthesis can work faster at slightly higher temperatures - only used in temperate countries such as the UK)

• Artificial lighting (plants can photosynthesise for longer)

• Increasing carbon dioxide content of the air inside (plants can photosynthesise quicker)

• helps control water supply - limiting factor will not be water, needs water for photosynthesis.

controlling the climate inside an enclose space (greenhouse) requires knowledge of l___ ____

limiting factors

can manipulate that to have no factors limiting = more photosynthesis

what are polythene tunnels

large plastic tunnels that cover crops

how polythene tunnels help crop yield (3)

• They can protect crops grown outside from the effects of the weather, including excessive wind, rain and extreme temperatures

• They also increase the temperature slightly inside the tunnel

• They can prevent the entry of pests that can damage plants or diseases that can kill plants

If a plant is given unlimited light, carbon dioxide and water and is at a warm temperature:
the only thing limiting the rate at which it can photosynthesise is…..

If a plant is given unlimited light, carbon dioxide and water and is at a warm temperature:

the only thing limiting the rate at which it can photosynthesise is its own ability to absorb these materials and make them react

how do all these things actually make crop yield more

plants will grow bigger and faster, higher crop yields

what are fertilisers

fertilisers increase the amount of key nutrients in the soil for crop plants, meaning that they can grow larger and are more healthy, which increases yields

why are fertilisers needed e.g. for the same reused field

As crop plants take up these mineral ions from the soil, the mineral ions need to be replaced if crops are grown repeatedly in the same field (i.e. year after year)

• Fertilisers are used to replace these mineral ions

what are pesticides

why do they help (2)

these chemicals kill off unwanted insects and weed species, meaning that there is less damage done to crop plants by insects, as well as reducing competition from other plant species, which increases yields

NPK fertiliser and why they are useful

• Nitrogen:

  • Absorbed in the form of nitrates

  • Needed to make amino acids which are the building blocks of proteins

  • Lack of nitrogen causes weak growth and yellowing of the leaves of plants

• Phosphorous:

  • Absorbed in the form of phosphates

  • Needed to make DNA and cell membranes

  • Lack of phosphorus can cause poor root growth and discoloured leaves

• Potassium:

  • Absorbed in the form of various compounds of potassium

  • Allows enzyme reactions to take place to produce ATP in respiration as well as being needed for the enzymes involved in photosynthesis

  • Lack of potassium can cause poor growth of flowers and fruits, as well as brown spots on leaves

def:

insecticides

herbicides

fungicides

• Insecticides kill insect pests

• Herbicides kill plant pests

• Fungicides kill fungal pests

why are pests, weeds and fungi bad for crop yield

• Pests such as insects and other animals can damage crops by eating them

• Weeds can outcompete crop plants for space, water and soil nutrients

• Fungi can infect crop plants and spread disease which can affect growth and yield

what is biological control, can it happen naturally?

it does not _____ remove a pest, but keeps it at _____ levels

• Can happen naturally – for example, ladybirds eat aphids

• Usually, a species is introduced specifically to prey on the pest species – for example, parasitic wasps can control whitefly in glasshouse tomato crops

• As they are based on a predator-prey cycle, they do not completely remove a pest, but keep it at lower levels

pesticides advantages (3) and disadvantages (4)

think: effect is _____, organisms can devlop______

biological control advantages (5) and disadvantages (5)

draw yeast fungus cell

what does yeast anaerobic respiration equation have

glucose → ethanol + CO2

how does yeast help make bread

what happens to the ethanol

is the yeast killed? how?

• (after O2 runs out, yeast respires anaerobically)

• bread rises because of the CO2 produced when yeast respires anaerobically

• the bubbles make the dough rise

• the ethanol is evaporated in the heat (no alcohol in bread)

• then yeast is killed by high temperatures during baking

Practical: Investigating Anaerobic Respiration in Yeast

(see how temperature affects rate of anaerobic respiration in yeast)

DIAGRAM

method for yeast experiment

• Mix yeast with sugar solution in a boiling tube

  • The sugar solution provides the yeast with glucose for anaerobic respiration

• Carefully add a layer of oil on top of the solution

  • This prevents oxygen from entering the solution (prevents aerobic respiration in the yeast)

• Using a capillary tube, connect this boiling tube with another boiling tube that is filled with limewater

• Place the boiling tube with yeast and sugar solution into a water bath at a set temperature and count the number of bubbles produced in a fixed time (e.g. 2 minutes)

  • The rate that carbon dioxide is produced by yeast can be used to measure the rate of anaerobic respiration (i.e. the rate of fermentation)

• Change the temperature of the water bath and repeat

what should the results show and why

the higher the temperature, more CO2 bubbles

(higher temperature is closer to optimum temperature of enzymes in yeast, increase enzyme activity (FOR RESPIRATION) so more anaerobic products)

if its too high though enzymes will denature/yeast will die

yeast temperature CORMMSS

• C – We are changing the temperature in each repeat

• O – The type (species) of yeast we are using must be the same

• R – We will repeat the investigation several times at each temperature to make sure our results are reliable

• M1 – We will measure the number of bubbles (of carbon dioxide) produced

• M2 – in a set time period (e.g. 2 minutes)

• S – We will control the concentration, volume and pH of the sugar solution, as well as the mass of yeast added

how is yoghurt made

• sterilise equipment + pasteurise milk

  • to remove competition

  • or spoil taste/make unhealthy

• add lactobacillus to milk

• incubate so it ferments

• lactobacillus uses sugar lactose to anaerobically respire, producing lactic acid

• this acid thickens and sours the milk

  • also acts as a bit of a preservative (acid)

• then cooled to stop lactobacillus action

condition	why and how is it controlled
aseptic precautions
nutrients
optimum temperature
optimum pH
oxygenation
agitation

benefits of fish farming vs wild-caught (4)

• The ability to selectively breed fish to ensure high quality, fast-growing fish

• The ability to protect against predators

• The ability to control water quality (many wild-caught fish have significant levels of pollutants such as mercury in their flesh)

• The ability to control feeding to ensure rapid growth

methods of good fish farming (acronym)

WPD WFS

wise practises drive well functioning systems

w

what does each stand for

W - water quality

P - predation - intra/inter

D - disease

W - waste removal

F - feeding

S - selective breeding

explain each

• why to fix

• how to fix