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what are the benefits of transpiration?

there is constant water to help keep plant cool, for photosynthesis.
water creates turgor pressure which helps support the plant and stops it wilting
minerals needed by plant can be brought in form the soil along with water


what four things affect transpiration rates?

light intensity
air movements
air humidity


what needs to be done to increase transpiration?

increase in light intensity, temp and air movements
decrease in humidity


how does light affect transpiration

brights means more as during the dark stomata close. photosynthesis cant happen in the dark so they close. when stomata are closed water canot escape


how does temp affect transpiration?

when warm particles have more energy to evaporate and diffuse out of the stomata


ho does air movement affect transpiration?

air movements helps it become faster as if there isnt any then the water just surrounds the leafs and wont move away. high concentration inside and outside so no movement. wind helps move water vapor to allow transpiration


how does air humidity affect transpiration?

if the air is humid there is lots of water already in it so there is no difference between leaf and air. diffusion happens fastest when there is a big differnece i concentration


how have plants adapted to not lose water?

waxy cuticle covering upper epidermis to make it waterproof
stomata on underside to slow diffusion in the cold and dark
bigger and larger the number of stomate means more water is lost. plants in hot climates have few small ones on the underside of leaf.


what caused stomata to close and open?

guard cells have a special kidney shape that opens and closes he stomata as the guard cells go turgid or flaccid.


what do stomata do?

allow gasses in and out for photosynthesis


when are stomata usualy open and closed?

open during day as they are sensitive to light. closed at night when its dark


what are the three minerals needed for plant growth?

nitrates, phosphates, potassium


what are nitrates needed for in plants?

for making amino acids and proteins, for cell growth.


if a pant does not have enough nitrates what happens

growth will be poor and will have yellow older leaves


what are phosphates needed for?

respirations and growth. dna and cell membrane productions


if a plant doesn't have enough phosphates what happens?

poor root growth and discolored leaves


what is potassium needed for ?

to help enzymes needed for photosynthesis and respirations.


if a plant doesnt have enough potassium what happens?

poor flower and fruit growth. discolored leaves too


why is magnesium used and why in small amounts?

for making chlorophyll needed for photosynthesis. without it leaves turn yellow


how are minerals taken in?

by the roots using active transport


why doesnt diffusion of minerals work in roots?

because there is a small concentration of minerals in the soul and its higher in the roots hairs so it wont go in.


what is active transport?

uses energy from respiration to help pull minerals into the roots against the concentration gradient


what causes decay?

microorganisms like soil bacteria nd fungi known as decomposers


what does the rate of decay depend on

temperatures (needs to be warm)
water amount (needs to be moist for fast decay)
oxygen amount (decay is faster when there is more oxygen available)


what are the optimum conditions for decay?

warm, moist, plenty of oxygen.
this causes microorganisms to reproduce nd grow more quickly and can then decay other living things better.


what is a detritivore?

feed on dead and decaying matter. they break it up into smaller bits, this produces a bigger surface area for smaller decomposers to decay it


what is a saprophyte?

they also feed on decaying matter but they do so with extracellular digestion/ they feed by secreting digestive enzymes onto the material outside their cells. the enzyme breaks down the material in to smaller bits which can then be absorbed by the saprophytes. usually fungi


what are the methods of food preservation?

adding slat or sugar
adding vinegar


how do these methods of food preservation work?

keeps decomposers out,
slows down their reproduction rate,
stops them reproducing at low temps,
takes away water which they need to decompose,
damage the cells,
kill them with acid


what is intensive farming?

trying to produce as much food as possible form your land,animals or plants


what are the most popular methods of intensive farming?

reducing energy lost at each stage in a food chain to make it more efficient


how is intensive farming, reducing of energy lost achieved?

herbicides kill weeds. this allows more energy form sum to fall on crops not weeds
pesticides kill animals that eat crops. no energy is transfered to to other food chains
battery farming animals. kept close together to stop wasted energy as they move


what does intensive farming allow us to do?

produce lots of food form less land witch means a hugh variety of top quality food all year round at cheap prices


what is it called when plants are gown without soil?

hydroponics, its another form of intensive farming where the plants are grown nutrient solutions instead of soil.


what are the advantages of hydroponics?

mineral levels can be controlled more accurately. disease can also be controlled


what are the disadvantages of hydroponics?

lots of fertilizers are used. there is also no soil to anchor the roots and support the plants


what are the environmental issues with hydroponics?

removal of hedges to make fields destroys habitats and leads to soil erosion
careless use of fertilizers can lead to eutrophication
farming of animals intensively is harmful and cruel (battery chickens)


wht is the issue with pesticides?

they can also kill animals that are not pests which can lead to shortage of food for animal higher up food chain


what is the problem of pesticides being passed up food chains?

they can stick in ecosystems and be passed along chains. it accumulates along the chain and gets more toxic towards the top where levels are highest


what was the case of DDT and otters?

a pesticide called DDT was used and it accumulated along food chains and the otter ended up getting toxic levels of it and almost wiping them out


what is biological control?

using living things instead of chemicals to control a pest.


examples of biological control?

aphids eat roses and vegetables. pest. ladybirds are predators of aphids so they can keep numbers down


what are the advantages of biological control

no chemicals means less pollution and disruption of food chains. less risk to people e eating foods
you dont have to keep repeating treatments like chemicals


what are he disadvantages of biological control?

a predator introduced might be useless and not eat pest
predator could eat useful species
predators species might increase and get out of control
predator might not stay in area where its needed


what are orgainc fertilisers?

animal manure/compost
recycles nutrients left in plant and animal waste. it is not as good as fertilizers but its bette for environment


what is crop rotation?

growing a cycle of different crops on a field each ear. it stops pests and diseases of one crops building up and stops nutrients running out. most crop rotations include nitrogen fixing bacteria crops such as legumes that put nitrates back into the soil


how is varying seed planting times used in faring?

it avoids major pests for that crop and eliminates the use of pesticides


what methods are used in organic farming/?

organic fertilizers
crop rotation
varying seed planing times
biological control


orgainicwhat are the advantages of organic farming?

fewer chemicals.
less rick of toxic chemicals in food
better for the environment.
less river pollution.
it doesn't disrupt food chains
ethical to animals


what are the disadvantages of organic farming?

takes more space than intensive
labour intensive, more jobs, more expensive
cant grow as much food