Evolution and Genetic Engineering Environmental impact on phenotype

Environmental impact on phenotype An organism’s final appearance (phenotype) is the result of the interaction between it’s genotype and the environment it develops in. This can be shown as a word equation: genotype + environment = phenotype

Environmental impact on phenotype Studies to investigate the effect of different environmental factors on phenotype are carried out using identical twins (human) or clones (plants) Why?

Environmental impact on phenotype Notes genotype + environment = phenotype To investigate the impact of environmental factors on phenotype, scientists can conduct twin, or clone, studies. Because the twins are genetically identical, any differences in phenotype must be due to environment.

Environmental impact on phenotype Notes: Give an example of how environment can influence the phenotype of human identical twins during growth Give an example of how environment can influence the phenotype of humans after growth is complete.

Environmental impact on phenotype Think! Will the effects of these environmental factors be passed onto the organisms offspring? Why / why not?

Environmental impact on phenotype Note Differences in phenotype caused by environmental factors (‘acquired characteristics’) are not passed down from one generation to the next. Acquired characteristics therefore have little evolutionary significance, as they play no part in natural selection.

Evolution and Genetic Engineering Natural selection

Natural Selection Think! Does every organism get a chance to pass on it’s genes? Why / why not? What could this have to do with evolution?

Natural Selection Notes Natural selection is the process by which organisms that are better adapted to their environment survive and breed, while those less well adapted fail to do so. So the better adapted organisms are more likely to pass their characteristics to the next generations.

The Peppered Moth Watch this video Now collect the cut-out of ‘The Peppered Moth Story’, and stick it – in the correct order – in your notes

Natural Selection Summary Sexually reproducing organisms show genetic variety Some organisms are better adapted to their surroundings than others This allows them to survive and pass on these favourable genes – natural selection Over time, natural selection can result in the creation of new species - evolution

Evolution and Genetic Engineering Selective Breeding

Selective Breeding People rely on plants and animals to supply us with many of the things we need. Can you think of some examples?

Selective Breeding All of the species of plants and animals that we eat or use today are derived from wild ancestors However, some look very different. Have a look at the cows on the next slide…

What differences can you see? Selective Breeding ‘Wild’ cow ‘Beef’ cow What differences can you see?

Selective Breeding Note Selective breeding is the selection of individuals which possess desirable characteristics and breeding them to produce the next generation.

Selective Breeding Notes Answer Q1+2 in Tp204 in sentences Think! What do you think are some of the problems / limitations of selective breeding?

Selective Breeding Notes Collect the table ‘Problems in Selective Breeding’ and use the green booklet (8.4, page 3) to complete it.

Evolution and Genetic Engineering

Genetic Engineering Notes Another method of artificial selection is genetic engineering Genetic engineering is the transfer of DNA from one type of organism to a different organism

Genetic Engineering Bacterial cell

Genetic Engineering Notes Collect a ‘Genetic Engineering’ diagram Use Torrance p206 to fill in the missing information and stick into your notes. Then attempt Tp207 Q3(b)

Advantages and Disadvantages of Genetic Engineering Using the information in the green booklet 8.5 page 2+3, draw a table like the one below and complete it with 5 advantages and 3 disadvantages of genetic engineering Advantages of genetic engineering Disadvantages of genetic engineering

Advantages of genetic engineering Disadvantages of genetic engineering Completely different species can be combined Organism shows only the desired characteristic Large quantities can be produced Easier to purify product Faster than selective breeding Bacteria can’t produce complex proteins Difficult to insert genes without damaging host cell Might produce harmful by-products Possible release of GM organisms into environment Expensive

Genetic Engineering Vs Selective Breeding Genetic engineering and selective breeding are two methods by which scientists can alter the genotype of another species for the benefit of humankind. On the flipchart paper, compare the two methods.

Genetic Engineering Debate You are now going to look at some of the arguments surrounding the use of genetic engineering. Collect the sheet of statements and cut them out Use the statements to produce a table as shown on Tp213

Uses of Genetic Engineering Think! What was being produced using genetic engineering in the video? Where was this originally obtained? What do you think the benefits are of the genetically engineered product over that of the original source?

Uses of Genetic Engineering Use the information on Tp207-211 to answer Tp211 ‘Testing your Knowledge’ in sentences