WEAKNESSES - use of biological resources

anaerobic respiration in yeast

glucose → ethanol + co2

anaerobic respiration in bacteria

glucose → lactic acid

features of fermenter (6)

• nutrients - in medium for growth

• water cooled jacket - keeps water at optimum temperature for enzymes so they don’t denature = high rate of reaction = high yield

• pH probe - pH at optimum level for enzymes = high rate of reaction = high yield

• stirrers - constant access to nutrients = growth, even temperature throughout = no hot spots

• sterile air pump - oxygen = respiration = energy = growth

• sterilised container - kills microorganisms = less competition with lactobacillus = growth

practical for measuring respiration rate of yeast depending on conditions

• add yeast mixture to test tube (yeast, distilled water, sugar)

• layer of oil for anaerobic conditions

• connect bung and delivery tube to another test tube with water

• water bath at certain temperature

• count number of bubbles per minute

• rate of co2 = bubbles / time in seconds

• repeat with different water bath temperatures

characteristics you may want to selectively breed (3)

• yield of products

• disease resistance

• fertility

process of selective breeding (5)

• from stock choose male and female with best characteristic

• breed them

• select male and female offspring who have best characteristics

• breed them

• repeat over many generations until whole population have characteristic

advantages of artificial insemination (4)

• safer for cow

• quicker and cheaper to transport semen instead of bulls

• semen can be used on multiple cows

• semen can be stored after the bull has died

what is controlled in a fish farm? (7)

• maintaining water quality - monitor temperature, pH, oxygen, remove faeces and bacteria, pesticides

• intraspecific predation - separated by size, fed regularly

• interspecific predation - cages and nets, separated by species

• controlling disease - pesticides, antibiotics, remove dead fish

• removing waste products - removal of faeces - supplies nitrates - algal blooms - eutrophication

• controlling the quality and frequency of feeding - quality pellets with amino acids for growth, regularly in small amounts to prevent obesity.

• selective breeding - breed disease resistance, larger fish, more meat

why do we do fish farming? (2)

• fish is a good source of protein

• we are overfishing the seas

define restriction enzyme

recognises specific sequences of DNA and cut the DNA at these points

define ligase enzyme

join two pieces of DNA together

define recombinant DNA

DNA from two organisms joined together

define vector

take up pieces of DNA and insert this recombinant DNA into other cells

two types of vectors

• plasmid - small DNA molecules transferred between bacteria

• virus - inserts the DNA into the organism they infect

describe the process of genetic engineering

• restriction enzyme - cut out the DNA to replicate from the gene

• cut a section of the plasmid with the same restriction enzyme

• ligase - join the DNA to the plasmid

• plasmid inserted back into bacterium

• replicate in a fermenter

define transgenic

transfer of genetic material from one species to a different species

advantages of genetically modified plants (3)

• increase food production = yield

• pesticide resistance = unaffected = kill weeds = yield

• insect resistant = less herbicides = less bioaccumulation = yield

disadvantages of genetically modified plants (3)

• superweeds - pesticide resistant gene becomes adopted

• affect food chains/humans

• unnatural and unethical

process to grow a plant from cuttings (4)

• cut below a node

• dip in auxins

• put in watered soil

• cover with bag and mist

methods for artificial plant reproduction

• micropropagation

• cuttings

examples of natural plant reproduction

strawberry runners

method of micropropagation (5)

• remove explant with scalpel

• sterilise

• sterile agar with nutrients (glucose and auxin)

• divides by mitosis

• split the callus to make many clones

process of SCNT (6)

• extract nucleus of body cell to clone

• insert into enucleated egg cell

• electric shock

• divides by mitosis

• forms embryo

• insert into surrogate uterus for gestation period

what can be used instead of a vector to insert a gene

gene gun

how can cloned transgenic animals be used to produce human proteins? (3)

• animals make protein naturally in their milk

• insert human genes into their cells

• produce human proteins in milk

examples of human proteins made from cloned transgenic animals

• human antibodies for arthritis, cancer

• spider silk goats