Trophic Levels Flashcards
What are trophic levels
Different stages of the food chain
Consisting of one or more organisms that perform a specific role in the food chain
What does each trophic level contain
1 = producers 2= primary consumers 3= secondary consumers 4= tertiary consumers
What animals are in trophic levels 1 2 and 3
2 = herbivores. 3 = carnivores 4 = carnivores that way other carnivores ( apex predators)
What’s biomass
The mass of living material
What do pyramids of biomass show
The relative masses of trophic levels
Each bar shows the relative mass of living material at a trophic level
What happens to the biomass as you go up a trophic level
It gets lost and decreases each time
Only about 10% is passed on
Why is biomass lost
Organisms don’t eat every part of what Its consuming
It’s not all absorbed in the food they ingest - turns to faeces
It’s converted into other substances like waste from glucose or urea
How do you calculate the efficiency of biomass transfer
Biomass transferred to the next level / biomass available at the previous level
x 100
What is food security
Having enough food to feed a population
What can threaten food security
Population increase
Demands for certain food increase
New pests and pathogens affecting farms and crops
How can we maintain fish stocks
Fishing quotas
= limita in number and size of fish that can be caught - so stopping overfishing in areas
Net size = reduces number of unwanted fish by changing the mesh size for the fish ur fishing
How can farming be made more efficient
Limiting the movement of life stock so they use less energy and we can control their body temp
What is biotechnology
Where living things and biological processes are used and manipulated to produce a useful product
What is genetic engineering
Transferring a useful gene from one organism to another
What can bacteria be made into and how
It can be genetically engineered to make human insulin
What happens in the first steps of genetically engineering bacteria
Remove plasmid from bacterium
Restriction enzymes cuts teh insulin gene out of a human chromosome
What does the restriction enzyme do in genetic engineering of bacteria
It recognises specific sequences of DNA and the cut DNA at these points
This cut leaves one of the DNA strands with unpaired bases called a sticky end
The same restructuring enzyme cuts open the plasmids so the DNA and plasmid both have the same sticky ends
Making them mix together
How do the sticky ends if the plasmid and human insulin gene join
An enzyme called ligase is added
It’s joins the sticky ends to produce recombinant DNA
What happens to the recombinant DNA in genetic engineering of bacteria
It’s inserted into a bacterium
This is grown in a vat under controlled conditions
You will end up with millions of bacteria that produce insulin
What is mycoprotein and how’s it’s made
Made from the fungus fusarium which is grown in aerobic conditions on glucose syrup
The fungal biomass is harvested and pitched to make mycoprotein
What is mycoprotein used for
To make high-protein meat substitutes for vegetarian meals
How can biotechnology help developing counties have enough food
GM crops can be produced that are resistant to pests
GM crops can be modified to grow better in drought conditions
They can be modified to produce more nutritional value
Why do people not agree with biotechnology
People argue that people can’t afford food so we need to tackle poverty crisis first
Counties may become dependent on counties who sell GM seeds
