New technology in biology

Transcription

1 New technology in biology Aims You have been asked to test a board game that can be used to revise the key concepts in this chapter. Work through the tasks below to show your understanding of these topics before testing the board game. Task 1: Genetics 1 a Complete the Punnett square below to show the inheritance of flower colour. The allele for red flowers is R. The allele for white flowers is r. b Describe in detail the difference between R and r in the genetic cross above. c Use your results from the Punnett square to describe the appearance of possible offspring in this genetic cross.

2 2 Fill in the statements below to describe genetically inherited disorders. Use the following words. genes inherited haemophilia parents diseases Some are caught from the people around you, whilst others can be in a person s genes. Genetically inherited disorders are conditions passed from to their offspring in their. Examples include cystic fibrosis,, and polydactyly. 3 Polydactyly is a genetic disorder that results in a child being born with extra digits on their hands or feet. It is caused by a dominant allele. a Calculate the probability of a baby inheriting polydactyly with a mother of Pp alleles and a father of Pp alleles. You may wish to draw a Punnett square to help you. b Explain why a person cannot be a carrier of polydactyly.

3 Task 2: Selective breeding, genetic engineering, and cloning 1 Match the halves of sentences below to describe the process of selective breeding. For a long time humans have bred Selective breeding is a method of First the desired characteristics of Then parents with high levels of these characteristics are selected. producing organisms with desired are bred together. dogs, cats, and horses to carry out specific jobs. These two individuals for many generations. Offspring displaying the most desired characteristics This is repeated a certain species are chosen. display the desired Eventually all of the offspring will are selected and bred again. 2 Complete the following table to describe some advantages and disadvantages of selective breeding. Advantages Disadvantages

4 3 Use the statements below to complete the table comparing the processes of genetic engineering and cloning. Write the correct statement number in the table. 1 Plant cuttings and Dolly the sheep. 4 The alteration of an organism s genes to produce desired 7 Frost-resistant tomatoes or antibioticproducing bacteria 2 Genes are taken from another organism with the desired characteristic and inserted into the target organism at an early stage of its development. 5 When used for plants, this technique is cheap and results are obtained quickly. All the plants are genetically identical so they will all have the desired Scientists believe that this technique can be used to prevent extinction of animals and in medical research. 8 For plants, this can be done using plant cuttings. For animals, this can be done using cell cloning or tissue culture. 3 The replication of an organism s genes to produce offspring that are genetically identical. 6 Massively reduces the variety of genes available (gene pool) and increases the risk of disease. There is also the risk that a change in the organism s environment can destroy a species completely. Some people also think that this technique is unethical when carried out on animals. 9 A quick method of making organisms with desired Genetic engineering Cloning Description of technique How this process works An example of this technique Possible advantages Possible disadvantages

5 Task 3: Biotechnology 1 Select the correct words in the paragraph below to describe how bread can be made. Flour, water, and bacteria/viruses/yeast are needed to make dough. The dough is then left in a cold/warm/hot place. The dough rises because the bacteria/viruses/yeast respire, converting sugars/starch/fats in the flour into ethanol and oxygen/carbon dioxide/nitrogen oxide. The gas is trapped as bubbles inside the dough, while ethanol condenses/solidifies/evaporates in the oven. 2 Reorder the following statements to describe how beer and wine are made. Order Plant sugar is added to a large container often the plant needs to be crushed. The container is sealed to keep out oxygen and microorganisms. The liquid is bottled or put into barrels, ready for use. Yeast is added to ferment the sugar into alcohol. Sediment is removed from the liquid, often by filtration. The mixture is left until the sugar has fermented into alcohol. 3 The production of bread, beer, and wine rely on a process called fermentation. Write a word equation for this reaction.

6 4 Complete the flow diagrams below to describe how cheese and yoghurt are made.

7 5 Describe the role of bacteria in fermentation. 6 Link the following commercial uses of enzymes with their descriptions. making baby food making fruit juice removing stains Adding enzymes such as proteases and lipases in biological washing powders by breaking down the stain into water-soluble substances. Adding pectinase to digest pectin in cell walls, making fruit easier to squeeze, releasing more juice. Adding proteases to food to break down proteins into amino acids, making the food easier to absorb. 7 Choose from the statements below those that correctly describe what happens when an enzyme is denatured. The enzyme dies so it can no longer catalyse reactions. The shape of the enzyme changes permanently so it can no longer catalyse reactions. The enzyme has been used up so cannot be used again. The enzyme melts so it can no longer catalyse reactions.