Option B- Biotechnology and bioinformatics (15/25 hours)

B.1 Microbiology: organisms in industry

Serendipity has led to scientific discoveries—the discovery of penicillin by Alexander Fleming could be viewed as a chance occurrence. (1.4)

Theory of knowledge

Alexander Fleming discovered penicillin in England in 1928, on a discarded
petri dish. To what extent was Dr Fleming’s discovery a lucky observation, or
do we only perceive what we are open to?

Understandings

• Microorganisms are metabolically diverse.
• Microorganisms are used in industry because they are small and have a fast growth rate.
• Pathway engineering optimizes genetic and regulatory processes within microorganisms.
• Pathway engineering is used industrially to produce metabolites of interest.
• Fermenters allow large-scale production of metabolites by microorganisms.
• Fermentation is carried out by batch or continuous culture.
• Microorganisms in fermenters become limited by their own waste products.
• Probes are used to monitor conditions within fermenters.
• Conditions are maintained at optimal levels for the growth of the microorganisms being cultured.

Applications and skills

• Application: Deep-tank batch fermentation in the mass production of penicillin.
• Application: Production of citric acid in a continuous fermenter by Aspergillus niger and its use as a preservative and flavouring.

• Application: Biogas is produced by bacteria and archaeans from organic matter in fermenters.

• Skill: Gram staining of Gram-positive and Gram-negative bacteria.

• Skill: Experiments showing zone of inhibition of bacterial growth by bactericides in sterile bacterial cultures.

• Skill: Production of biogas in a small-scale fermenter.

B.2 Biotechnology in agriculture

Assessing risks and benefits associated with scientific research—scientists need to evaluate the potential of herbicide resistance genes escaping into the wild population. (4.8)

Understandings

• Transgenic organisms produce proteins that were not previously part of their species’ proteome.
• Genetic modification can be used to overcome environmental resistance to increase crop yields.
• Genetically modified crop plants can be used to produce novel products.
• Bioinformatics plays a role in identifying target genes.
• The target gene is linked to other sequences that control its expression.
• An open reading frame is a significant length of DNA from a start codon to a stop codon.
• Marker genes are used to indicate successful uptake.
• Recombinant DNA must be inserted into the plant cell and taken up by its chromosome or chloroplast DNA.
• Recombinant DNA can be introduced into whole plants, leaf discs or protoplasts.
• Recombinant DNA can be introduced by direct physical and chemical methods or indirectly by vectors.

Applications and Skills

• Application: Use of tumour-inducing (Ti) plasmid of Agrobacterium tumefaciens to introduce glyphosate resistance into soybean crops.
• Application: Genetic modification of tobacco mosaic virus to allow bulk production of Hepatitis B vaccine in tobacco plants.

• Application: Production of Amflora potato (Solanum tuberosum) for paper and adhesive industries.
• Skill: Evaluation of data on the environmental impact of glyphosate-tolerant soybeans.
• Skill: Identification of an open reading frame (ORF).

 

Aims

Aim 7: Use of bioinformatics to determine sequences to be modified.

Aim 8: There are ethical and political implications in the introduction of the genetically modified potato Amflora in Europe.

B.3 Environmental protection

Developments in scientific research follow improvements in apparatus—using tools such as the laser scanning microscope has led researchers to deeper understanding of the structure of biofilms. (1.8)

Theory of knowledge

Emergent properties are the outcome of the interaction of the elements of a system. In what context is a reductionist approach to science productive and in what context is a reductionist approach problematic?

International mindedness

During oil spills scientists from different parts of the world work together to protect the environment.

Understandings

• Responses to pollution incidents can involve bioremediation combined with physical and chemical procedures.
• Microorganisms are used in bioremediation.
• Some pollutants are metabolized by microorganisms.
• Cooperative aggregates of microorganisms can form biofilms.
• Biofilms possess emergent properties.
• Microorganisms growing in a biofilm are highly resistant to antimicrobial agents.
• Microorganisms in biofilms cooperate through quorum sensing.
• Bacteriophages are used in the disinfection of water systems.

Applications and Skills

• Application: Degradation of benzene by halophilic bacteria such as Marinobacter.
• Application: Degradation of oil by Pseudomonas.
• Application: Conversion by Pseudomonas of methyl mercury into elemental mercury.
• Application: Use of biofilms in trickle filter beds for sewage treatment.
• Skill: Evaluation of data or media reports on environmental problems caused by biofilms.

B.4 Medicine AHL

Developments in scientific research follow improvements in technology—innovation in technology has allowed scientists to diagnose and treat diseases. (1.8)

Theory of Knowledge

• There have been cases around the world where subjects have died as a consequence of participating in a gene therapy research protocol. How is the decision to proceed with risky procedures made?

• What constitutes an acceptable level of risk for allowing humans to be involved in scientific research?

Understandings

• Infection by a pathogen can be detected by the presence of its genetic material or by its antigens.
• Predisposition to a genetic disease can be detected through the presence of markers.
• DNA microarrays can be used to test for genetic predisposition or to diagnose the disease.
• Metabolites that indicate disease can be detected in blood and urine.
• Tracking experiments are used to gain information about the localization and interaction of a desired protein.
• Biopharming uses genetically modified animals and plants to produce proteins for therapeutic use.
• Viral vectors can be used in gene therapy.

Applications and Skills

• Application: Use of PCR to detect different strains of influenza virus.
• Application: Tracking tumour cells using transferin linked to luminescent probes.• Application: Biopharming of antithrombin.
• Application: Use of viral vectors in the treatment of Severe Combined Immunodeficiency (SCID).
• Skill: Analysis of a simple microarray.
• Skill: Interpretation of the results of an ELISA diagnostic test.

B.5 Bioinformatics

Cooperation and collaboration between groups of scientists—databases on the internet allow scientists free access to information. (4.3)

Theory of Knowledge

• Knowledge claims justified by reference to databases raise unique knowledge questions. How reliable are knowledge claims justified by reference to data sources developed for different purposes by different researchers using different methods?

Understandings

• Databases allow scientists easy access to information.
• The body of data stored in databases is increasing exponentially.
• BLAST searches can identify similar sequences in different organisms.
• Gene function can be studied using model organisms with similar sequences.
• Sequence alignment software allows comparison of sequences from different organisms.
• BLASTn allows nucleotide sequence alignment while BLASTp allows protein alignment.
• Databases can be searched to compare newly identified sequences with sequences of known function in other organisms.
• Multiple sequence alignment is used in the study of phylogenetics.
• EST is an expressed sequence tag that can be used to identify potential genes.

Applications and Skills

• Application: Use of knockout technology in mice to determine gene function.
• Application: Discovery of genes by EST data mining.
• Skill: Explore chromosome 21 in databases (for example in Ensembl).
• Skill: Use of software to align two proteins.
• Skill: Use of software to construct simple cladograms and phylograms of related organisms using DNA sequences.

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