Use of Biological Resources Flashcards
Name three ways you can increase crop yield
Use of glasshouses and polytunnels
Use of fertilisers
Use of Pest control
What are the advantages of keeping plants enclosed in a glasshouse?
Will keep plants free from pests and diseases
Why do farmers use fertilisers?
To replace missing elements or provide more of them, ensuring crops have enough nutrients
What do pests include?
micro-organisms, insects and animals
What is biological control?
an alternative to using pesticides
Using other organisms to reduce the number of pests, either by encouraging wild organisms or adding new ones
What is an advantage of biological control?
Can have a longer lasting affect than spraying pesticides
Can be less harmful to wildlife
What is a disadvantage of biological control?
They can get out of control
What can we use yeast for?
Brewing beer
What is beer made from?
grain - usually barley
What is done to the barley grains?
They are allowed to germinate for a few days, during which the starch in the grains is broken down into sugar
Then they are dries in a Kiln
This is called Malting
What is done to the malted grain?
It is mashed up with water which is added to produce a sugary solution
How do people get rid of the bits whilst brewing beer?
They sieve it
What is added to beer mixture to give it it’s bitter flavour?
Hops
What is the second step to brewing beer?
The yeast is added and the mixture is incubated
What does yeast do?
It ferments the sugar into alcohol
How does yeast die?
By the rising concentration of alcohol (ethanol)
What is done to the beer after the yeast stage?
It is drawn off through a tap and then pasteurised
What is meant by pasteurised?
heated - to kill off any yeast left in beer and stop fermentation
What is the final step of beer brewing?
It is casked ready to be sold
How can you investigate the rate of CO2 production by yeast under different conditions?
Mix sugar yeast and distilled water into test tube
Attach bung and other end in test tube of water
Place yeast mixture in water bath
Leave the tube to warm up then count bubbles
What is respiration controlled by?
enzymes
What is selective breeding?
Mating the best organisms to get good offspring
What are some best features, chosen when you selectively breed?
- Maximum yield (meat, milk, grain)
- Good health and disease resistant
- Speed, fertility
- In plants - attractive flowers, nice smell
List the processes done in selective breeding
Selection of best characteristics
Breed them with each other
Select best offspring, breed them together
Repeat over several generations
What will selective breeding eventually give farmers?
better and better yields
How can fishing be controlled?
FISH FARMING
Why are fish kept in cages?
To stop them using as much energy swimming about
Protection from predetation
Why are fish diet controlled?
To maximise the amount of energy they get to make them big and grow fast
Where are young fish kept?
In special tanks - to ensure as many survive as possible
Why is it important to keep bigger fish from smaller fish?
To avoid the bigger fish eating the smaller fish
Intraspecific predation
When fish are kept in tanks, what has to be controlled?
- temperature, pH and oxygen level
- amount of food
- amount of fish waste and poo (filtering)
What can enzymes be used to do?
Cut up DNA or join DNA pieces together
What do restriction enzymes recognise?
specific sequences of DNA and cut the DNA at these points
What are ligase enzymes used for?
to join 2 pieces of DNA together
What is 2 different bits of DNA stuck together known as?
recombinant DNA
What is the use of a vector?
It’s something that’s used to transfer DNA into a cell
Name the two sorts of vectors
Plasmids
Viruses
What are plasmids?
small, circular molecules of DNA that can be transferred between bacteria
What do viruses do?
insert DNA into the organisms they infect
How can bacteria be grown in huge numbers?
By placing them in a fermenter
Why are some crops genetically modified?
To increase food production
Name two ways crops can be genetically modified
They can be resistant to insects
They can be resistant to herbicides
What is a disadvantage of genetically modifying crops?
transplanted genes may get out into the environment
could affect food chains
What is the name given to cloning plants?
Micropropagation
What are small pieces of plants called?
explants
Why are explants sterilised in cloning?
to kill any microorganisms
What are the explants grown in?
in vitro - a petri dish with nutrients and growth hormones
What is a cell without a nucleus called?
an enucleated cell
How are cells in cloning stimulated?
with a small electric shock
