AP4E16~1.PDF

Unit 2 Genetics Glossary Part 2  Diploid cell Sexually reproducing organisms inherit their DNA from both parents, meaning they have two copies of every chromosome (a maternal (mums) copy and a paternal (dads) copy) These two copies are called homologous chromos...

Unit 2 Genetics Glossary Part 2  Diploid cell Sexually reproducing organisms inherit their DNA from both parents, meaning they have two copies of every chromosome (a maternal (mums) copy and a paternal (dads) copy) These two copies are called homologous chromosomes and the cell is described as being diploid (‘di’ = two)  Meiosis Meiosis is a special type of division that halves the number of chromosomes so as to produce sperm or eggs (gametes) The resulting cells are described as being haploid (‘ha’ = half) and will develop into the sex cells (gametes) used in sexual reproduction Meiosis also promotes genetic variation in offspring by: 1. crossing over (puts new allele combo’s together) 2. random assortment (sperm/eggs get different sets of alleles to each other – explains why siblings are NOT twins!) Meiosis Meiosis – mistakes of…. Punnett squares  Genotype AA – Homozygous dominant Means a sperm carrying an ‘A’ allele fused with an egg also carrying the ‘A’ allele. Aa – Heterozygous Means a sperm carrying an ‘A’ allele fused with an egg carrying an ‘a’ allele. aa – Homozygous recessive Means a sperm carrying an ‘a’ allele fused with an egg also carrying the ‘a’ allele.  Phenotype Phenotype is the observable trait that results from the expression of a gene and its alleles and the actions (or inactions) of the protein produced. Phenotype is the result of both nature (DNA/genotype) and nurture (environment) because it is environmental conditions that trigger gene expression (transcription and translation). Environmental conditions here refers to and includes: temperature, pH, and the concentration of other molecules in the cell. High concentrations of certain molecules could trigger expression of particular genes, whereas low concentrations of the those molecules might not (and vice versa)  Phenotype = gene expression of genotype AA – Homozygous dominant Means only protein coded for by the A allele can be present in a cell to produce the phenotype Aa – Heterozygous Means both proteins coded for by the A allele and the a allele can be present in a cell. *WITH only the A produced protein determining the phenotype aa – Homozygous recessive Means only protein coded for by the ‘a’ allele can be present in a cell to produce the phenotype. Karyotype Karyotype  Pedigree Analysis The Components of a Pedigree: Squares are used to indicate males in a family. Circles are used to indicate females. If the individual is “affected" by the trait (dominant or recessive) we darken the shape. A line between a male and a female indicates a marriage or union. A line drawn down from the marriage line indicates offspring.  Modes of inheritance Mode of inheritance Faulty Allele Affected individuals Healthy Individuals 1.Autosomal Dominant A AA or Aa aa 2.Autosomal b bb BB or Bb (carrier) Recessive Female 3.Sex Linked (X) XH Male Female Male XHXH or Dominant XH Y Xh Xh Xh Y XH Xh 4.Sex Linked (X) Xr Female Male Female Male Recessive Xr Xr Xr Y XRXR or XRXr XRY Pedigree Analysis Pedigree Analysis Worked example Worked example Aa Aa AA AA aa or or Aa Aa Worked example  Worked example Aa Aa AA aa or Aa  Ethics List the three ethical The three approaches used to guide ethical decision making are: approaches ∙ Consequence-based ∙ Duty-based ∙ Virtues-based Define a ∙ A consequence-based approach to ethical decision places central importance For example: Consequence-based on the consideration of the consequences of an action (the ends), with the aim approach to ethical decision making to achieve maximisation of positive outcomes and minimisation of negative Results from scientific trials may be used to justify effects. making a new drug available. Define a Duty-based ∙ A Duty- and/or rule-based approach is concerned with how people act (the For example: approach to ethical means) and places central importance on the idea that people have a duty to decision making act in a particular way, and/or that certain ethical rules must be followed, A teacher has a professional obligation and set of policies regardless of the consequences that may be produced. governing their decision making in school. Define a ∙ A Virtues-based approach is person- rather than action-based. Consideration is For example: Virtues-based given to the virtue or moral character of the person carrying out the action, approach to ethical decision making providing guidance about the characteristics and behaviours a good person The morally right thing to do may avoid testing on would seek to achieve to then be able to act in the right way. animals even if benefits could be justified from the research  Ethics List the 5 ethical The five concepts considered in ethical decision making are: concepts that ∙ Integrity are considered in ∙ Respect ∙ Beneficence ethical decision ∙ Non-maleficence making ∙ Justice Define Integrity ∙ Integrity: the commitment to searching for knowledge and understanding and the ∙ Integrity includes publishing on a public platform honest reporting of all sources of information and communication of results, whether negative data from scientific trials. favourable or unfavourable, in ways that permit scrutiny and contribute to public knowledge and understanding. Define Respect ∙ Respect: involves consideration of the extent to which living things have an intrinsic ∙ Respect includes avoiding animal welfare issues value and/or instrumental value; giving due regard to the welfare, liberty and (intrinsic value), ensuring consent in human trials autonomy, beliefs, perceptions, customs and cultural heritage of both the individual (intrinsic value and autonomy), providing labelling and the collective; consideration of the capacity of living things to make their own of information on GMO products (due regard to decisions; and when living things have diminished capacity to make their own decisions beliefs, own decision making)… ensuring that they are empowered where possible and protected as necessary. Define ∙ Beneficence: the commitment to maximising benefits and minimising the risks and ∙ Beneficence includes using GMO bacteria to Beneficence harms involved in taking a particular position or course of action. produce human insulin (benefits) to avoid immune rejection from other sources (min harm), after safety has been assured through testing (minimising risks) Define ∙ Non-maleficence: involves avoiding the causations of harm. However, as positions or ∙ Avoid harm – to animals, people, the non-maleficence courses of actions in scientific research may involve some degree of harm, the concept environment…. of non-maleficence implies that the harm resulting from any position or course of action should not be disproportionate to the benefits from any position or course of action. Define Justice ∙ Justice: the moral obligation to ensure that there is fair consideration of competing ∙ Justice requires fair and equal access to treatment claims; that there is no unfair burden on a particular group from an action; and that so may require government funding to ensure there is fair distribution and access to the benefits of an action. drugs are affordable for the poor.