A2 3.4 Unit 4: 3.4.2 Growing up, growing old and passing on your genes

The effects and diseases of ageing
Candidates should be able to discuss the issues facing society in terms of the increasing number of elderly people in the population and treating conditions associated with old age.

AS 3.1 Unit 1: 3.1.4 Microorganisms use us for food, shelter and their reproduction

Bacterial diseases
When provided with appropriate information, candidates should be able to evaluate the evidence for the links between use of antibiotics and the development of MRSA and other antibiotic resistant bacteria

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A2 3.5 Unit 5: 3.5.6 People and their microorganisms

Antibacterial resistance
Humans have introduced large amounts of antibacterial agents into the environment of bacteria. Evolution of resistance to antibacterial agents MRSA. When provided with appropriate information, candidates should be able to evaluate evidence relating to the impact of the widespread use of antibacterial agents

A2 3.5 Unit 5: 3.5.5 Plants can reduce the impact of the use of fossil fuels on climate change

Biofuels reduce the use of fossil fuels
When provided with appropriate information, candidates should be able to evaluate the environmental and social impacts of the use of biofuels. When provided with appropriate information, candidates should be able to evaluate the impact of the use of biofuels on national and global carbon dioxide emissions

A2 3.4 Unit 4: 3.4.4 New genes for old

Genetically modified organisms (pp.26)
Selective breeding programmes have been used to create new strains and species of crop plants. The use of gene technology in producing GM organisms. Herbicide-resistant crop plants and cattle with high milk yields.

Candidates should consider the ethical and moral issues relating to the production of GM organisms:

• ownership of genes
• ownership of the modified organisms
• financial benefits
• sanctity of the species

A2 3.4 Unit 4: 3.4.2 Growing up, growing old and passing on your genes

Genetic Counselling and Mendelian inheritance
Candidates should be aware that many conditions needing treatment, or with the potential to need treatment, are inherited.

Cystic fibrosis as an example of monohybrid inheritance. Sickle cell anaemia as an example of codominant alleles. ABO blood groups as an example of inheritance involving multiple alleles. Rhesus blood groups. The potential dangers inherent in a rhesus negative mother giving birth to rhesus positive babies.

Candidates should be able to give reasons why experimental results may only approximate to Mendelian ratios. They should be able to apply the chi-squared test to establish the significance of any differences from predicted ratios. Genetic counselling. The use of information from family history and genetic screening to advise parents, the screening of embryos.

Candidates should consider the ethical and moral issues relating to genetic counselling.

A2 3.4 Unit 4: 3.4.4 New genes for old

Recombinant DNA
Candidates should consider whether or not selective breeding is ethically different from the use of modern gene technologies.

Genetically modified organisms
Selective breeding programmes have been used to create new strains and species of crop plants. The use of gene technology in producing GM organisms. Herbicide-resistant crop plants and cattle with high milk yields.

Candidates should consider the ethical and moral issues relating to the production of GM organisms

• ownership of genes
• ownership of the modified organisms
• financial benefits
• sanctity of the species

GM organisms
Environmental Impact Assessment. The impact on communities and ecosystems of the large-scale introduction of genetically modified organisms, as exemplified by soya and maize When provided with appropriate information, candidates should be able to evaluate evidence and make balanced judgements between the need to meet the demands for certain crops and the need to conserve the environment.

A2 3.4 Unit 4: 3.4.2 Growing up, growing old and passing on your genes

Genetic Counselling and Mendelian inheritance
Candidates should be aware that many conditions needing treatment, or with the potential to need treatment, are inherited.

Cystic fibrosis as an example of monohybrid inheritance. Sickle cell anaemia as an example of codominant alleles. ABO blood groups as an example of inheritance involving multiple alleles. Rhesus blood groups. The potential dangers inherent in a rhesus negative mother giving birth to rhesus positive babies.

Candidates should be able to give reasons why experimental results may only approximate to Mendelian ratios. They should be able to apply the chi-squared test to establish the significance of any differences from predicted ratios. Genetic counselling. The use of information from family history and genetic screening to advise parents, the screening of embryos.

Candidates should consider the ethical and moral issues relating to genetic counselling.

A2 3.5 Unit 5: 3.5.7 Gene expression is controlled by a number of features

Regulation of transcription and translation
Candidates should be able to:

• interpret information relating to the use of oncogenes and tumour suppressor genes in the prevention, treatment and cure of cancer
• evaluate the effect on diagnosis and treatment of disorders caused by hereditary mutations and those caused by acquired mutations

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A2 3.5 Unit 5: 3.5.8 Gene cloning technologies allow study and alteration of gene function in order to better understand organism function and to design new industrial and medical processes

Medical diagnosis
The use of labelled DNA probes and DNA hybridisation to locate specific genes. Once located, the base sequence of a gene can be determined by

• restriction mapping
• DNA sequencing

Many human diseases result from mutated genes or from genes that are useful in one context but not in another, e.g. sickle cell anaemia.
DNA sequencing and the PCR are used to produce DNA probes that can be used to screen patients for clinically important genes.
The use of this information in genetic counselling, e.g., for parents who are both carriers of defective genes and, in the case of oncogenes, in deciding the best course of treatment for cancers.

A2 3.4 Unit 4: 3.4.4 New genes for old

Recombinant DNA
Candidates should consider whether or not selective breeding is ethically different from the use of modern gene technologies.

Genetically modified organisms
Selective breeding programmes have been used to create new strains and species of crop plants. The use of gene technology in producing GM organisms. Herbicide-resistant crop plants and cattle with high milk yields.

Candidates should consider the ethical and moral issues relating to the production of GM organisms

• ownership of genes
• ownership of the modified organisms
• financial benefits
• sanctity of the species

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A2 3.5 Unit 5: 3.5.2 People change communities

GM organisms
Environmental Impact Assessment. The impact on communities and ecosystems of the large-scale introduction of genetically modified organisms, as exemplified by soya and maize. When provided with appropriate information, candidates should be able to evaluate evidence and make balanced judgements between the need to meet the demands for certain crops and the need to conserve the environment.

A2 3.4 Unit 4: 3.4.4 New genes for old

Recombinant DNA
Candidates should consider whether or not selective breeding is ethically different from the use of modern gene technologies.

Genetically modified organisms
Selective breeding programmes have been used to create new strains and species of crop plants. The use of gene technology in producing GM organisms. Herbicide-resistant crop plants and cattle with high milk yields.

Candidates should consider the ethical and moral issues relating to the production of GM organisms

• ownership of genes
• ownership of the modified organisms
• financial benefits
• sanctity of the species

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A2 3.5 Unit 5: 3.5.2 People change communities

GM organisms
Environmental Impact Assessment. The impact on communities and ecosystems of the large-scale introduction of genetically modified organisms, as exemplified by soya and maize. When provided with appropriate information, candidates should be able to evaluate evidence and make balanced judgements between the need to meet the demands for certain crops and the need to conserve the environment.

A2 3.4 Unit 4: 3.4.1 IVF - babies for those who cannot conceive naturally

Reproduction and contraception
Candidates should be able to discuss the ethical and moral issues relating to the use of different forms of contraception. When provided with appropriate information, candidates should be able to evaluate evidence about the benefits and risks associated with the use of different forms of contraception.

IVF
Causes of infertility

• low sperm count
• blocked oviducts

Use of IVF to treat women with blocked oviducts

• using FSH to stimulate multiple ovulation
• removal of the oocytes from the oviducts
• fertilisation
• culture to the 8 - 16 cell stage
• re-implantation of some of the embryos

Candidates should consider the ethical and moral issues relating to the use of IVF

• the fate of embryos that are not implanted
• their possible use in scientific experiments
• the extent to which IVF should be available

AS 3.2 Unit 2: 3.2.2 Cell division - growth, repair, reproduction and cancer

Cancer - mitosis out of control
When supplied with appropriate data candidates should be able to evaluate evidence for genetic and environmental factors increasing the incidence of cancer, including skin, lung and colon cancer.

Candidates should be able to interpret data showing the occurrence of cancers and links with possible causal factors, both genetic and environmental.

Candidates should be able to discuss the moral and ethical issues associated with the legality of cigarette smoking and treatment of diseases linked to smoking.

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A2 3.4 Unit 4: 3.4.2 Growing up, growing old and passing on your genes

Where variation comes from
Interaction of genes and the environment produce the phenotype. Twin studies show the effects of genes and environment.
When supplied with appropriate data, candidates should be able to evaluate evidence for the relative influences of genetic and environmental factors on phenotype.

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A2 3.4 Unit 4: 3.4.7 Hypothermia and diabetes - when controls fail to work

Diabetes - a disease of our times
Candidates should be aware of the health implications of undiagnosed or untreated diabetes. When provided with appropriate information, candidates should be able to evaluate evidence showing correlations between life-style and the incidence of diabetes.

AS 3.3 Unit 3 Investigative and Practical Skills in AS Human Biology (AS Centre-Assessed Unit)

This unit will address the following aspects of the AS subject criteria. The ability to:

• demonstrate and describe ethical, safe and skilful practical techniques, selecting appropriate qualitative and quantitative methods