Cloning and biotechnology (6.2.1)
Navigate to resources by choosing units within one of the unit groups shown below.
Delivery guides are designed to represent a body of knowledge about teaching a particular topic and contain:
- Content: A clear outline of the content covered by the delivery guide
- Thinking Conceptually: Expert guidance on the key concepts involved, common difficulties students may have, approaches to teaching that can help students understand these concepts and how this topic links conceptually to other areas of the subject
- Thinking Contextually: A range of suggested teaching activities using a variety of themes so that different activities can be selected which best suit particular classes, learning styles or teaching approaches.
Content (from A-level)
|6.2.1 Cloning and biotechnology|
|(a)||(i) natural clones in plants and the production of natural clones for use in horticulture
(ii) how to take plant cuttings as an example of a simple cloning technique
|To include examples of natural cloning and the methods used to produce clones (various forms of vegetative propagation).
Dissection of a selection of plant material to produce cuttings.
|(b)||(i) the production of artificial clones of plants by micropropagation and tissue culture
(ii) the arguments for and against artificial cloning in plants
|To include an evaluation of the uses of plant cloning in horticulture and agriculture.
|(c)||natural clones in animal species||To include examples of natural clones (twins formed by embryo splitting).|
|(d)||(i) how artificial clones in animals can be produced by artificial embryo twinning or by enucleation and somatic cell nuclear transfer (SCNT)
(ii) the arguments for and against artificial cloning in animals
|To include an evaluation of the uses of animal cloning (examples including in agriculture and medicine, and issues of longevity of cloned animals).
HSW9, HSW10, HSW12
|(e)||the use of microorganisms in biotechnological processes||To include reasons why microorganisms are used e.g. economic considerations, short life cycle, growth requirements
processes including: brewing, baking, cheese making, yoghurt production, penicillin production, insulin production and bioremediation.
|(f)||the advantages and disadvantages of using microorganisms to make food for human consumption||To include bacterial and fungal sources.
|(g)||(i) how to culture microorganisms effectively, using aseptic techniques
(ii) the importance of manipulating the growing conditions in batch and continuous fermentation in order to maximise the yield of product required
|An opportunity for serial dilutions and culturing on agar plates.
|(h)||(i) the standard growth curve of a microorganism in a closed culture
(ii) practical investigations into the factors affecting the growth of microorganisms
An opportunity for serial dilutions and the use of broth.
M0.1, M0.3, M0.5, M1.1, M1.3, M2.5, M3.1, M3.2, M3.4, M3.5, M3.6
|(i)||the uses of immobilised enzymes in biotechnology and the different methods of immobilisation.||To include methods of enzyme immobilisation
an evaluation of the use of immobilised enzymes in biotechnology
examples could include,
4 minute video of embryo splitting (formation of identical twins) in vitro, first filmed in 2007.
This provides answers to FAQs about animal cloning, including a discussion of telomeres and the longevity of cloned animals. It could be used as a resource for individual research study and accompanying questions or an essay or PowerPoint brief.
Factfile on Dolly the sheep, the first cloned mammal ever to be created from an adult cell. It could be used in class individually or as a group resource for further research.
6 minute video on animal cloning from the DNA learning centre, suitable for class use.
A report of 2013 research to improve the SCNT technique to give cloned offspring with normal lifespans. The site has useful links to other articles concerning Dolly the Sheep and human cloning and could be used alongside the Cloning Fact Sheet to provide an updated view.
This summarises some applications of biotechnology, the benefits of using microorganisms, techniques for immobilising enzymes, the standard growth curve and batch and continuous fermenter culture.
Video showing bacterial multiplication and explanation of factors limiting growth.
Good overview of applications of immobilised enzymes, plus their advantages and disadvantages.
Approaches to teaching the content
Cloning: It is important to establish the principles of mitosis and totipotency of meristematic cells before looking at and gaining practical experience of examples of plant cloning. Principles of stem cuttings and a class tissue culture protocol are included here, with a choice of other horticultural practical contexts included in the final section of the guide. The loss of genetic diversity in cloned crops can be linked synoptically with the same problem arising though to a lesser degree from selective breeding. In this section two resources consider the value of seed and gene banks to counteract this problem. Black sigatoka disease on bananas is a useful example of the impact of a disease on cloned plants. For animal cloning the link between regeneration of tissue, pluripotent stem cells and cloning is explored in the Planaria video.
Biotechnology: The concepts of stem cells, aseptic technique, serial dilution and methods of counting cells and calculating cell density are covered in the resources listed below.
Common misconceptions or difficulties students may have
- Candidates need to distinguish between genetic uniformity (all individuals genetically identical) and genetic similarity when discussing examples of natural and artificial clones.
- Candidates often think that cloned offspring are more susceptible to disease, this is not the case. Varieties that are cloned are chosen for their desirable qualities, which may include resistance to certain diseases. However a new disease to which one individual is susceptible will affect the entire population the same way.
- Candidates should be sure they understand the difference between reproductive and non-reproductive applications of cloning.
- On graphs showing change in feedstock, microbe numbers and metabolites, candidates often fail to clarify which are chemicals and which are cells, and to logically relate one parameter to another.
- Students may fail to understand the reason for and use of log scales on graphs for plotting numbers of bacteria.
- Microbiology practicals may require complex calculations at the end to get meaningful results, e.g. serial dilution.
Conceptual links to other areas of the specification – useful ways to approach this topic to set students up for topics later in the course
11 minute video summarising mitosis. The whole presentation or just the introductory 3-4 minutes on the significance of mitosis could be used for revision before exploring cloning in plants and animals.
2 minute video outlining procedure for taking cuttings of Pelargoniums on a commercial scale, to help inform an understanding of the process of taking stem cuttings (a) (ii) and as an example for an evaluation of plant cloning in horticulture (b).
The site includes a video demonstration of the technique, student worksheets and teaching notes for carrying out a class practical. The goal is to grow a callus culture which produces small leaves from a cauliflower mini-floret. This procedure provides an introduction to aseptic technique, PAG7.
The SAPS protocol has been updated to increase reliability and to prevent contamination by fungus. Preparation of the cytokinin-containing growth medium is described on the teaching notes and shown on a video. The worksheet materials link to the context of propagating endangered species at the Royal Botanic Gardens, Kew and stress the concept of totipotency.
Use this seed catalogue site to show pictures of new coloured varieties of cauliflowers such as Graffiti (red), Sunset (orange) and Trevi (green) to add interest to the cauliflower cloning practical. Green romanesco-type cauliflowers may be available in supermarkets to provide a source of material with novelty value.
Resource for case study work on the effect of disease on genetically identical banana crop. This links to 4.1.1 (a).
6.2.1 (a) and (b) activity contexts explored here include propagating blackberries, strawberries, potatoes and yams and the spread of disease in a genetically identical population with reference to the Great Potato Famine in Ireland (1845-1849).
6.2.1 (c) and (d) contexts explored here include twins, cloning extinct animals and cloning pets.
6.2.1 (e) – (i) concerns microbial and enzyme biotechnology for a range of applications. Those included here are examining commercial mycoprotien and practical instructions for growing Spirulina as a food supplement, practical activities using microbes in food preparation, exploring probiotics and a practical to make soft-centred chocolates using invertase.
This web page outlines four ways in which gardeners can clone blackberry plants. Students could be asked why gardeners want to do this, given that blackberries can be picked from brambles which commonly grow wild in both towns and cities. This could lead on to a discussion of:
- selective breeding
- examples of features in a wild blackberry fruit and plant that could be improved upon
- the difference between sexual reproduction needed for artificial selection and the asexual reproduction needed to clone the desirable offspring.
Students could each be given one sprouting potato in mid-March and be challenged to see who can grow the most new potatoes by the end of May or June.
The method described requires little digging, and could use leaf mould (leaves kept in sacks overwinter to rot down), allowing discussion of mineral cycling. If a greenhouse is available the potato chunks can be planted and harvested earlier.
This gallery of images shows the natural phenotypic variation in potatoes in their place of origin, Peru and Bolivia. This can be contrasted with the variation in appearance of potatoes in a UK supermarket, or with the widespread growing of one variety (Lumper) in Ireland in the mid-nineteenth century. If combining resources listed to grow potatoes and explore genetic variation in potatoes, see also the Plant and Animal Cloning Question Sheet.
- Blight on the Landscape (Irish potato famine and plant pathology)
- Battling Bark and Beetle (Dutch Elm disease)
- Hunt for Diversity (Search for unused varieties of crops).
This commercial website is the shop window of an animal cloning company.
Students may be interested in the introductory video of two cloned dogs on the home page, the pricing structure for having pet genetic material preserved and cloned, the news page which includes stories of the world’s first cloned cat and horse, and two videos on the FAQ page, on DNA and chromosomes and lab footage of the process of SCNT.
A task involving critical evaluation of the service offered would make a useful summary assignment.
This detailed resource gives instructions for the culture of the algal food supplement Spirulina. It could be used for a comprehension of research assignment by students or by technicians to devise a small-scale Spirulina culture method for a class practical or for demonstration.
Recipes for using microbes to make bagels, elderflower ‘champagne’, ginger beer and yoghurt are provided. There are other interactive and downloadable microbiology resources on this site.
Factors such as temperature and substrate concentration could be varied in the recipes and the process timed to gain an appreciation of the rate of enzyme reactions occurring.
5 minute video discussion of using a model stomach to test effectiveness of delivery of probiotic bacteria to the small intestine in a water, milk of cheese matrix.
Class discussion points could include how best to produce probiotic bacteria as health supplements via an industrial biotech process, when probiotics are most needed (e.g. after taking antibiotics), natural sources of probiotics and current research on the importance of the gut flora to health.
Probiotic products like Actimel, Yakult and veterinary health supplements could be shown or researched.
The video explains to teachers how to run a practical making soft-centred chocolates using the enzyme invertase. Sugar cubes with and without invertase are covered in melted chocolate, or sugar fondant balls with or without invertase are covered in chocolate, left, and later tested to see if the ones containing enzyme have a softer centre than the controls.
If the chocolates are to be eaten at the end of the practical the work should be carried out in a food technology lab or hygiene precautions observed (work surfaces covered with clean foil, etc) in a classroom.
OCR’s resources are provided to support the teaching of OCR specifications, but in no way constitute an endorsed teaching method that is required by the Board and the decision to use them lies with the individual teacher. Whilst every effort is made to ensure the accuracy of the content, OCR cannot be held responsible for any errors or omissions within these resources. We update our resources on a regular basis, so please check the OCR website to ensure you have the most up to date version.
© OCR 2015 - This resource may be freely copied and distributed, as long as the OCR logo and this message remain intact and OCR is acknowledged as the originator of this work.