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unit 2-2.7 and unit 3- 3.1-3.2 - Coggle Diagram
unit 2-2.7 and unit 3- 3.1-3.2
2.7 genetic control of metabolism.
wild strains- micro-organisms that occur naturally can be selected and cultured
mutagenesis- the creation of mutations. the rate can be increased by exposing an organism to mutagenic agents for example uv lights, radiation.
recombinant DNA technology is the transfer of genes from 1 species to another. a vector is DNA used to carry foreign genetic material into another cell. restriction endonuclease cuts the required gene. the same endonuclease cuts the plasmid open and because it was the same one, the 'sticky ends' are complementary. ligase binds them together.
selectable markers used to determine if DNA has been successfully inserted. restriction site- site of cut. origin of replication- ensures new cells have copy of plasmid. safety gene- ensures it cannot function outside the lab. regulatory sequences.
yeast used as it is a eukaryotic cell, same as those whcih the genes came from however also contains plasmids.
3.1 food security and photosynthesis.
food security- the ability of the human population to access food of a sufficient quality and quantity
sustainable food is food which doesnt harm or affect the land it grows on.
more sustainable to produce plants as they produce more energy per unti area as livestock lose energy as you go up the trophic levels.
plant crops- potato ceral roots and legumes
photosynthesis- light energy can be absorped, reflected and transmitted.
light is absorbed by photosynthetic pigments which are chlorophyll A AND B and carotenoids.
the absorption spectrum is a graph which shows the wavelengths of light being absorbed and the action spectrum shows how effective photosynthesis is at each wavelength.
stage 1 photosynthesis- light dependant reactions- absorbed energy excites electrons. electrons transferred along ETC which releases energy, generating ATP. water is split into oxygen which diffuses into the atmosphere and hydrogen which binds to NADP and is carried to stage 2.
stage 2 photosynthesis- the Calvin cycle, carbon fixation. CO2 from atmosphere joins to ribulose bi-phosphate which forms 3- phosphoglycerate. this is catalysed by the enzyme RuBisCo.3PG joins hydrogen from NADPH to form glyceraldehyde 3- phosphate. which is turned into glucose and RUBP to continue the cycle.
3.2 plant and animal breeding
selective characteristics- resistance to pests and diseases, desirable physical characteristics, ability to survive adverse conditions, increased crop yield and nutritional value.
outbreeding- breeding between unrelated organisms. inbreeding- breeding between related organisms. bred for several generations until the population breeds true to the desired gene due to the elimination of heterozygous. inbreeding depression is causes by an increase in the frequency of individuals who are homozygous for the recessive, deleterious allele.
cross breeding- individuals from different breeds produce a new crossbred population with improved characteristics- F1 generation. the mating of 2 different inbred homozygous cultivars produces offspring who are heterozygous (F1 hybrids). they show an increased vigour, yield and fertility.
field trials- controlled experiments to compare performance of different cultivars and to evaluate GM crops. independent variable- what your investigating. dependant variable- remains constant. reliability- complete replicates to take into account variability. validity- control variables. accuracy- measurement techniques. random- eliminates bias.