1. Genetic Engineering & DNA Profiling

In brief:Genetic engineering alters an organism's DNA. DNA profiling creates a unique genetic 'fingerprint' for identification.

Genetic Engineering (GM)

Genetic engineering involves artificially altering an organism's DNA by transferring a gene from a donor to a host organism, creating a genetically modified organism (GMO).

Gene isolation: locate the desired gene
Cutting: use restriction enzymes to cut the gene from donor DNA and cut open a bacterial plasmid
Insertion: use ligase enzyme to splice the gene into the plasmid
Transformation: insert the recombinant plasmid into a host cell (e.g. bacterium)
Expression: the host cell expresses the new gene, producing the desired protein

Examples: human insulin produced by GM bacteria; Bt crops resistant to insects; Golden Rice with vitamin A.

DNA Profiling

Creates a unique genetic 'fingerprint' using non-coding DNA (which varies between individuals).

DNA extracted from sample
DNA amplified using PCR
DNA cut with restriction enzymes
Fragments separated by gel electrophoresis
Pattern of bands = DNA profile

Uses: forensic identification, paternity testing, solving crimes, identifying genetic disorders.

PCR (Polymerase Chain Reaction)

A technique to amplify (make millions of copies of) a small DNA sample. Uses cycles of heating and cooling with DNA polymerase.

Recombinant DNA — Genetic engineering: recombinant plasmid formation
Wikimedia Commons (CC)

Key Points

1Genetic engineering: transfer a gene from donor to host using restriction enzymes and ligase
2GMO examples: human insulin from bacteria, Bt crops, Golden Rice
3DNA profiling uses non-coding DNA to create a unique genetic fingerprint
4Gel electrophoresis separates DNA fragments by size
5PCR amplifies tiny DNA samples into millions of copies
6Applications: forensics, paternity testing, genetic disorder screening

Learning Outcomes

Outline the concept of genetic engineering and its applications
Outline what is meant by DNA profiling and its potential uses
Model the steps involved in generating a DNA profile
Outline the principle of DNA sequencing
Use a genome database to search for alleles that are known to cause (or be responsible for) specific genetic diseases
Investigate patterns using a DNA profile, use primary or secondary data to support conclusions

2. Stem Cells & Ethical Issues

In brief:Stem cells offer potential therapies. Genetic technologies raise important ethical and sustainability questions.

Stem Cells

Stem cells are undifferentiated cells that can develop into many different cell types.

Pluripotent: can become almost any cell type (embryonic stem cells)
Multipotent: can become a limited range of cell types (adult stem cells)
Therapeutic cloning: creating stem cells with the patient's own DNA to avoid immune rejection

Uses of Stem Cells

Treating diseases: Parkinson's, spinal cord injuries, diabetes. Bone marrow transplants use blood stem cells.

DNA Sequencing & Bioinformatics

DNA sequencing determines the order of nucleotide bases. Bioinformatics uses computers to analyse genomic data. Genome databases store DNA sequences and allow researchers to search for alleles linked to genetic diseases.

Ethical Issues

Use of embryonic stem cells - destruction of embryos
GM foods - environmental impact, consumer choice, labelling
DNA databases - privacy, consent, data security
Genetic screening - discrimination, insurance implications
Gene editing (CRISPR) - designer babies, unintended consequences

Key Points

1Pluripotent stem cells can become almost any cell type; multipotent are more limited
2Therapeutic cloning uses patient's own DNA to avoid immune rejection
3DNA sequencing determines the order of bases; bioinformatics analyses the data
4Ethical concerns: embryo destruction, GM food safety, DNA privacy, genetic discrimination
5Genome databases help identify alleles causing genetic diseases

Learning Outcomes

Discuss the ethical issues arising from advancements in genetic technologies