Biology_A-level_Cie
-
1-1-the-microscope-in-cell-studies5 主题
-
1-2-cells-as-the-basic-units-of-living-organisms5 主题
-
2-1-testing-for-biological-molecules3 主题
-
2-2-carbohydrates-and-lipids8 主题
-
2-3-proteins6 主题
-
2-4-water2 主题
-
3-1-mode-of-action-of-enzymes5 主题
-
3-2-factors-that-affect-enzyme-action8 主题
-
4-1-fluid-mosaic-membranes4 主题
-
4-2-movement-into-and-out-of-cells12 主题
-
diffusion
-
osmosis
-
active-transport
-
endocytosis-and-exocytosis
-
investigating-transport-processes-in-plants
-
investigating-diffusion
-
surface-area-to-volume-ratios
-
investigating-surface-area
-
estimating-water-potential-in-plants
-
osmosis-in-plant-cells
-
osmosis-in-animals
-
comparing-osmosis-in-plants-and-animals
-
diffusion
-
5-1-replication-and-division-of-nuclei-and-cells6 主题
-
5-2-chromosome-behaviour-in-mitosis2 主题
-
6-1-structure-of-nucleic-acids-and-replication-of-dna4 主题
-
6-2-protein-synthesis5 主题
-
7-1-structure-of-transport-tissues4 主题
-
7-2-transport-mechanisms7 主题
-
8-1-the-circulatory-system7 主题
-
8-2-transport-of-oxygen-and-carbon-dioxide5 主题
-
8-3-the-heart4 主题
-
9-1-the-gas-exchange-system6 主题
-
10-1-infectious-diseases3 主题
-
10-2-antibiotics3 主题
-
11-1-the-immune-system4 主题
-
11-2-antibodies-and-vaccination6 主题
-
12-1-energy5 主题
-
12-2-respiration11 主题
-
aerobic-respiration-the-krebs-cycle
-
aerobic-respiration-role-of-nad-and-fad
-
aerobic-respiration-oxidative-phosphorylation
-
anaerobic-respiration
-
energy-yield-aerobic-and-anaerobic-respiration
-
anaerobic-adaptation-of-rice
-
aerobic-respiration-effect-of-temperature-and-substrate-concentration
-
structure-and-function-of-mitochondria
-
the-four-stages-in-aerobic-respiration
-
aerobic-respiration-glycolysis
-
aerobic-respiration-the-link-reaction
-
aerobic-respiration-the-krebs-cycle
-
13-1-photosynthesis-as-an-energy-transfer-process8 主题
-
13-2-investigation-of-limiting-factors2 主题
-
14-1-homeostasis-in-mammals8 主题
-
14-2-homeostasis-in-plants3 主题
-
15-1-control-and-coordination-in-mammals12 主题
-
the-endocrine-system
-
the-nervous-system
-
neurones
-
sensory-receptor-cells
-
sequence-of-events-resulting-in-an-action-potential
-
transmission-of-nerve-impulses
-
speed-of-conduction-of-impulses
-
the-refractory-period
-
cholinergic-synapses
-
stimulating-contraction-in-striated-muscle
-
ultrastructure-of-striated-muscle
-
sliding-filament-model-of-muscular-contraction
-
the-endocrine-system
-
15-2-control-and-coordination-in-plants3 主题
-
16-1-passage-of-information-from-parents-to-offspring5 主题
-
16-2-the-roles-of-genes-in-determining-the-phenotype7 主题
-
16-3-gene-control3 主题
-
17-1-variation4 主题
-
17-2-natural-and-artificial-selection7 主题
-
17-3-evolution2 主题
-
18-1-classification5 主题
-
18-2-biodiversity7 主题
-
18-3-conservation6 主题
-
19-1-principles-of-genetic-technology11 主题
-
19-2-genetic-technology-applied-to-medicine4 主题
-
19-3-genetically-modified-organisms-in-agriculture2 主题
-
1-1-the-microscope-in-cell-studies
-
1-2-cells-as-the-basic-units-of-living-organisms
-
2-1-testing-for-biological-molecules
-
2-2-carbohydrates-and-lipids
-
2-3-proteins
-
2-4-water
-
3-1-mode-of-action-of-enzymes
-
3-2-factors-that-affect-enzyme-action
-
4-1-fluid-mosaic-membranes
-
4-2-movement-into-and-out-of-cells
-
5-1-replication-and-division-of-nuclei-and-cells
-
5-2-chromosome-behaviour-in-mitosis
-
6-1-structure-of-nucleic-acids-and-replication-of-dna
-
6-2-protein-synthesis
-
7-1-structure-of-transport-tissues
-
7-2-transport-mechanisms
-
8-1-the-circulatory-system
-
8-2-transport-of-oxygen-and-carbon-dioxide
-
8-3-the-heart
-
9-1-the-gas-exchange-system
-
10-1-infectious-diseases
-
10-2-antibiotics
-
11-1-the-immune-system
-
11-2-antibodies-and-vaccination
recombinant-dna
Recombinant DNA
-
The genetic code is universal, meaning that almost every organism uses the same four nitrogenous bases – A, T, C & G. There are a few exceptions
-
This means that the same codons code for the same amino acids in all living organisms (meaning that genetic information is transferable between species)
-
Thus scientists have been able to artificially change an organism’s DNA by combining lengths of nucleotides from different sources (typically the nucleotides are from different species)
-
The altered DNA, with the introduced nucleotides, is called recombinant DNA (rDNA)
-
If an organism contains nucleotide sequences from a different species it is called a transgenic organism
-
Any organism that has introduced genetic material is a genetically modified organism (GMO)
Examiner Tips and Tricks
It is because of the universal genetic code that recombinant DNA can be formed. All forms of life use the same genetic code, which is the strongest piece of evidence for evolution. Remember, the genetic code is the basis for storing instructions that, alongside environmental influences, dictate the behaviour of cells and as a result, the behaviour of whole organisms.