Biological resources Flashcards
1
Q
How do glasshouses and polythene tunnels increase yield of crops
A
- Artificial heating to maintain optimum temp
- Artificial lighting
- protection from pests and diseases
- Additional CO2 in air
- Regular watering
2
Q
Effect of increased CO2 on glasshouses
A
- more co2 = more photosynthesis
- contributes to enhanced greenhouse effect
- contributes to global warming
- increases temperature on earth
- raises internal and external temperatures of glasshouses
3
Q
Organic feritilisers
A
mixture made from natural sources - manure, straw, compost
4
Q
Inorganic fertilisers
A
man-made chemicals that contain specific nutrients - nitrogen, potassium, phosphurus
5
Q
Fertiliser
A
a substance added to soil to provide nutrients that help plants grow
6
Q
Advantages of organic fertilisers
A
- Better for the environment
- Improves soil structure
- Cheaper
- Greater range of minerals released over longer period of time
7
Q
Disadvantages of Organic fertilisers
A
- Only replace a portion of the lost nitrogen
- Slow - has to be decomposed first
- May contain pests
- Difficult to apply
8
Q
Advantages of Inorganic fertilisers
A
- Inorganic replaces all the nitrogen and other lost ions
- Quicker process
- Easy to apply
9
Q
Disadvantages of inorganic fertilisers
A
- Leads to pollution problems
- Does not improve soil structure
- Requires regular reapplication
10
Q
How do fertilisers increase crop yield
A
- provides nutrients
- speeds up growth
- replaces nutrients that are removed from soil
11
Q
Pests
A
an organism that reduce the yield of crops causing economic damage to farmer
12
Q
Two bethods of controlling pests
A
pesticides or biological control
13
Q
biological control
A
uses predator species to reduce number of pests
14
Q
4 types of biological control
A
- Herbicides - kill pest plants (weed killers)
- Insecticides - kills insects
- Fungicides - kill fungi
- Molluscicides - kills snails and slugs
15
Q
Pesticides
A
kill specific pests to improve yield of crops
16
Q
Advantages of pesticides
A
- Reduces pest population
- can kill the whole population of pests
17
Q
Disadvantages of pesticides
A
- expensive - regular applications
- not specific - can kill unharmful animals
- pests can become chemical resistent
18
Q
Advantages of biological control
A
- organism only needs be introduced once - reproduce
- only one cost for initial introduction
- pest specific - only kills pest
- pest will not become resistent
- no effect on other animals in food chain
19
Q
Disadvantages of biological control
A
- takes time to reduce pest population
- not all population of pests killed
- expensive is re-populating required
20
Q
Role of yeast in production of bread
A
- Yeast respires aerobically = co2 and water
- Oxygen runs out
- yeast respires anaerobically
- produces CO2 and ethanol
- CO2 makes dough rise
- Dough is baked in oven
- CO2 bubbles expand and ethanol evaporates
21
Q
Role of lactobacillus in yogurt production
A
- Lactobacillus digests milk proteins
- respires anaerobically
- produces lactic acid
- lactic acid has a low pH
- drop in pH causes milk proteins to denature
- The mixture cogulates (thickens)
22
Q
Yogurt production
A
- The equipment is sterilised
- The milk is pasteurised between 85-95C to kill any bacteria and pathogens
- Milk is homogenised to disperse any fat globules
- Cool the milk
- lactobacillus is added + milk is cooled to 40-45C
- Pour into jars and cover
23
Q
fermenter
A
a vessel used to grow micro-organisms used for fermentation
24
Q
Aseptic conditions
A
prevent competition between unwanted organisms which prevents contamination
25
Sterilisation
Steam at high pressure cleans off any unwanted bacteria
26
Inlet
Nutrients enter
e.g amino acids for proteinshynthesis
e.g glucose for respiration
27
Temperature and pH
Constant optimum conditions for enzymes
28
Air Inlet
Oxygen for aerobic respiration
Filtered air prevents pathogen or unwanted bacteria
29
Cold Water
prevents enzymes from denaturing
monitors/control temperature
30
Stirring paddles
agitation of mixture
maximal enzyme contact for optimum reaction
31
Selctive Breeding an animal
- Choose two animals with the desired trait
- Breed them together
- Choose the offspring wiht the desired trait
- Breed the offspring together
- Repeat the process over many generations until all offspring consistently show the desired feature
32
Selective Breeding in plants
- choose two plants with the desired trait
- cross pollinate them
- choose the offspring with the desired traits
- cross pollinate the offspring
- repeat over many enerations until all plants have desired trait
33
Desired traits in animals
- non aggressive
- fast growing
- high production of meat/milk/eggs
- high production offspring
- high resistance to disease
- better quality fur
34
Desired traits in plants
- Give higher yields
- Resistant to diseases
- Resistant to pests
- survive harsh climates
- Have a better balance of nutrients in the crop
35
genetic engineering
transfering genes from one organism to another
36
Transgenic organisms
Organsims which have received genes from another species.
37
Vectors
Are animals that are used to transfer DNA of one organism to another
38
Plasmids
Small circular pieces of DNA in bacteria
39
Restriction enzymes
Enzymes that cut DNA at certain points - can cut out genes from DNA
40
How are restriction enzymes used
- restriction enzyme makes a cut and the fragements of DNA are called blunt ends
- a plasmid is removed from the bacterium and cut open with the same DNA restriction enzymes
- Restriction enzymes make staggered cuts, fragements of DNA with overlapping ends with complimentry bases, are called sticky ends
- A DNA ligase enzyme bonds between the nucleotides to make a single DNA strand
- The plasmid is now recombinant DNA
41
A vector introduced foreign DNA into bacteria cells
- Bacteriophafe attacks bacteria by attaching to the cell wall of the bacterium
- injects its DNA into the bacterial cell
- the DNA becomes incorporated into the DNA of the host cell
- results in the bacterium producing vital components/production of many virus particles
42
How is a gentically engineered virus used to transfer a gene into Bacteria
1. Genetically engineer the virus so that it contains the desired gene - it is now transgenic
2. Add the virus to a population of bacteria
3. The virus will bind to the bacteria, insert its genetic material (including the desired gene) into the bacteria
4. The viral DNA including the desired gene will be incorporated into the bacteria
5. The bacteria can now produce the protein that the desired gene codes for
43
How fo you genetically engineer bacteria to produce insulin
1. Isolate a bacterial plasmid
2. Using a restriction enzyme, cut out a section of the plasmid
3. Isolate the gene that produces insulin in a human chromosome (11)
4. Using the same restriction enzyme cut out the gene to produce insulin
5. The human insulin gene and plasmid join together due to complementry base pairing at the sticky ends
6. Use the enzyme ligase forms bonds between the insulin gene and the plasmid to form the recombinant DNA
7. Add the recombinant plasmid into a bacteria and incubate to allow it to grow and replicate to form lots of transgenic bacteria, all of which can produce insulin which can then be harvested
44
Genetic modification of plants involves
- introducinf new genes into a plant cell
- producing whole plants from just a few cells
45
Traits added to plants from GM
- extend there shelf life
- Plants can also become resistant to pests/herbicides
- Higher yield
- Better balance of proteins, carbohydrates, lipids, vitamins and minerals
- Resistance to extremes in weather e.g drought tolerance
- Resistance to disease/pathogens
- Increased salt tolerance
46
Advantages of GM plants
More precise method than selective breeding
Higher crop yield/better food quality
Less pesticide/herbicide used so less pollution
Disease resistant/pest resistant/herbicide resistant
47
Disadvantages of GM plants
Long term affects unknown
May affect food chains or enviroment
Reduces variation
Not accepted by public
48
Uses of genetically modified bacteria
- enzymes for washing powders
- enzymes in food industry
- human vaccines
