Biological resources Flashcards
How can you create optimal photosynthesis conditions
greenhouses prevent pests and diseases and allows water supply control
artificial light allows photosynthesis even during night
heaters can be used during winter to allow temperature requirements for photosynthesis, as paraffin burns, carbon dioxide produced as a by-product
how does fertiliser increase crops growth
e.g. nitrates to make proteins
growth and life processes effected without these minerals
farmers use fertiliser to replace missing minerals that had been used by previous crop
how does pest control reduce pests eating crops
pesticides - poisonous to humans and wildlife but remove pests
biological control - using natural organisms to reduce number of pests by either adding new ones or encouraging wild organisms e.g. parasites or disease causing organisms or predators
biological control is longer lasting but can eat other important organisms
how is milk produced
yoghurt sterilised to remove unwanted microbes
milk is pasteurised to kill any harmful microbes, followed by cooling
lactobacillus is added and the mixture is incubated in a fermenter
lactose sugar forms lactic acid
milk clots and solidifies into yoghurt
flavours can be added
how are conditions in fermenters kept for optimal growth
Nutrients provided in the liquid culture medium
PH is monitored and kept at optimal level
water cool jacket maintains optimal temperature
paddles stir mixture to ensure microbes can always access nutrients
sterile air pumped in when microbes need oxygen for respiration
superheated steam kills unwanted microbes that could compete with microbes and cause contamination
how is yeast used in the making of bread
dough heated allowing it to rise
enzymes break down carbohydrates
yeast uses sugars in aerobic respiration
when oxygen runs out anaerobic respiration occurs
produces ethanol
carbon dioxide accumulates in air pockets and the pockets expand
yeast is killed and alcohol boiled away as the bread is put in an oven
how to measure effect of changing temperature of yeast respiration rate
use sugar, yeast and distilled water and add to a test tube
use layer of oil to prevent oxygen entering
add bung and tube to another test tube
place tube with yeast into water bath set to different temperatures
count bubbles produced in a set time and co2 production = bubbles/time
repeat at different temps…
outline the process of selective breeding
- select stock with best characteristics
- breed them with each other
- select the best offspring and breed one again
- over many generations, desirable trait gets stronger and stronger
how can fish farming occur in cages
e.g. salmon
salmon kept in cages to save energy loss from them swimming about
cage prevents interspecific predation
fed using food pellets that is controlled to ensure they receive sufficient energy which can be used to grow and increase yield
young fish kept in special tanks to maximise survival, so bigger fish don’t eat little fish, also known as intraspecific predation
pesticides and biological control used to prevent disease and parasites
selective breeding occurs to reduce aggression and increase fish growth
how can fish farming occur in tanks
water monitoring to ensure pH, temperature, and oxygen level is ok
easy to control feeding frequency and food quality
filtered water can remove wate food and fish waste to reduce contamination and pollution
what are restriction enzymes
cut DNA at specific sequence points
ligase enzymes join the DNA pieces together
recombinant DNA produced
outline genetic engineering process
restriction enzyme cuts out desired DNA, it also cuts open the vector
Vector and desired DNA are mixed together using ligase
recombinant DNA formed following mixing
recombinant DNA inserted into other cells
now that cell can use the gene to produce protein wanted
what is a vector
something used to transfer DNA into another cell
what is transgenic
organism containing genes transferred from another species
outline micropropagation
explants removed from plant that is going to be cloned
explants sterilised and grown on a nutrient medium
explants grow and divide into smaller plants
small plants moved into soil to grow into many genetically identical copies of the original plant
Describe Nucleus transplanting
Nucleus removed from egg cell to produce enucleated cell
nucleus removed from adult body cell
diploid nucleus replaces to form embryo
cell stimulated to begin division by mitosis
dividing cell implanted into surrogate mother before being ready to be born
clone produced
list examples of how cloned transgenic animals can be used to produce human proteins
e.g. antibodies produced in cow/sheep’s milk. Can be used for therapy e.g. cancer therapy.
