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Core Concepts and Core Competencies
The GSA Education Committee maintains a list of core concepts and competencies that an undergraduate should acquire while taking an introductory genetics course. This learning framework is provided as a guide for educators to use while developing their classes.
Sample learning objectives are listed in drop-down menus, but are by no means a fully comprehensive list of objectives for that concept.
All GSA PREP original resources, recommended outside resources, and CourseSource genetics resources are presented using this genetics learning framework.
Click here for a PDF version of the Genetics Learning Framework.
| Core Category |
Core Concept |
Sample Learning Objectives
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Nature of Genetic Material |
How is DNA organized? |
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- Describe the types of DNA regions that do not encode proteins: the general organization, possible function, and frequency of genes and non-gene DNA sequences in a typical eukaryotic genome.
- Explain what is meant by single-nucleotide polymorphism (SNP) and short tandem repeat (STR), and explain how SNPs and STRs can be used as genetic markers even if they do not cause phenotypic changes.
- Discuss how DNA is packaged in the chromosomes in terms of histones, nucleosomes, and chromatin.
- Explain the meaning of ploidy (haploid, diploid, aneuploid etc.) and how it relates to the number of homologues of each chromosome.
- Describe how the positions of individual genes on a given chromosome are related to their positions on the homolog of that chromosome.
- Differentiate between a gene and an allele, including the recognition that genes may have many alleles.
- Explain the functional significance of packaging DNA into chromosomes and the lack of correlation between chromosome size and genetic information content.
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What are the molecular components and mechanisms necessary to preserve and duplicate an organism’s genome? |
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- Draw a simple line diagram showing a segment of DNA from a gene and its RNA transcript, indicating which DNA strand is the template, the direction of transcription and the polarities of all DNA and RNA strands.
- Describe the process of mitosis, transcription, and translation. How are mistakes in these processes identified and corrected?
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Transmission/Patterns of Inheritance |
What are the mechanisms by which an organism’s genome is passed on to the next generation? |
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- Distinguish between somatic and germline cells; listing similarities and differences.
- Compare and explain the inheritance of germline and somatic mutations.
- Describe, using diagrams, the sequence of events involving DNA in meiosis from chromosome duplication through chromosome segregation.
- Explain how meiosis is different from mitosis.
- Describe the difference between meiosis in mammalian males and females.
- Distinguish between sister chromatids and homologous chromosomes.
- Discuss how errors in chromosome number can arise during meiosis, and why such alterations can be detrimental.
- Calculate the probability of a particular gamete being produced from an individual, assuming independent segregation.
- Calculate the probability of a particular genotype, given independent segregation and random union of gametes between two individuals.
- Contrast the mechanisms of inheritance of nuclear and organellar genetic information
- Explain how independent assortment of alleles during meiosis can lead to new combinations of alleles of unlinked genes.
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How can one deduce information about genes, alleles, and gene functions from analysis of genetic crosses and patterns of inheritance? |
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- Interpret pedigree information to determine the suitability of a DNA marker for tracking a disease trait in a family.
- Draw a pedigree based on information in a story problem.
- Using pedigrees, distinguish between dominant, recessive, autosomal, X-linked, and cytoplasmic modes of inheritance.
- Predict the transmission of phenotypes associated with maternal effect genes.
- Explain why the terms “dominant” and “recessive” are context dependent and may differ at the cellular level or at the level of a pedigree.
- Calculate the probability that an individual in a pedigree has a particular genotype (using Bayesian inference if appropriate for course).
- Design genetic crosses to provide information about genes, alleles, and gene functions.
- Interpret the results of experiments comparing the phenotypes that result from single mutations in two different genes with the phenotype of the double mutant, contrasting epistatic and additive interactions.
- Explain how continuous traits are the result of many different gene combinations that can each contribute a varying amount to a phenotype.
- Evaluate how genes and the environment can interact to produce a phenotype.
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How does the phenomenon of linkage affect the assortment of alleles during meiosis? |
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- Use statistical analysis to determine how well data from a genetic cross or human pedigree analysis fits theoretical predictions including an explanation of the appropriate statistical test.
- Explain the meaning of a LOD score.
- Diagram the process of homologous recombination during meiosis and explain how it can lead to new combinations of linked alleles.
- Explain the role of homologous recombination in ensuring proper segregation of homologs in meiosis I.
- Explain how a specific combination of linked alleles (haplotype) can persist through many generations (linkage disequilibrium).
- Calculate gene linkage and genetic map distances and interference from the frequencies of progeny with recombinant phenotypes from genetic crosses.
- Explain how genetic distance is different from physical distance.
- Calculate the probability of a particular gamete being produced from an individual, provided map distance.
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Molecular Biology of Gene Function |
How is genetic information expressed so it affects an organism’s structure and function? |
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- Explain how the genetic code relates transcription to translation.
- Describe how expansion or retraction of triplet repeats can alter gene function and create a phenotype.
- Discuss how various factors might influence the relationship between genotype and phenotype (e.g. incomplete penetrance, variable expressivity, and sex-limited phenotype).
- Explain how abnormalities in gene dosage can affect phenotype.
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Gene Expression and Regulation |
How can gene activity be altered in the absence of DNA changes? |
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- Discuss the roles of types of RNA other than mRNA in expressing genetic information.
- Defend how most cells can have the same genetic content and yet have different functions in the body.
- Contrast the packaging of DNA into euchromatin versus heterochromatin in the context of histone modification, and DNA modification (where applicable).
- Discuss the potential roles of DNA modification, histone modification, and non-coding RNA in epigenetic inheritance, both somatic and germline.
- Discuss environmental impacts on epigenetic systems.
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How do genes and genomes control changes in an organism's structure and function throughout its life cycle? |
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- Describe how differential histone modification modulates gene activity and is utilized in developmental progression.
- Use a model systems to describe investigations of evo-devo.
- Describe genetic cascades; use the sex-determination cascade to explain how differential gene expression can result in the development of different sexes.
- Explain how polarity is established in a developing embryo using gene expression gradients.
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Genetic Variation |
How do different types of mutations affect genes and the corresponding mRNAs and proteins? |
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- Describe how duplications, deletions, inversions, and translocations can affect gene function, gene expression, and genetic recombination.
- Describe the same for transposable elements.
- Describe how mutations arise and how environmental factors can increase mutation rate.
- Cite examples of mutations that can be beneficial to organisms.
- Interpret results from experiments to distinguish between different types of DNA rearrangements.
- Distinguish between loss of function and gain of function mutations and their potential phenotypic consequences.
- Predict the most likely effects on protein structure and function of null, reduction-of-function, overexpression, dominant-negative and gain-of-function mutations.
- Compare the role of both loss and gain of function mutations in the origin of tumors.
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Evolution and Population Genetics |
What are the processes that can affect the frequency of genotypes and phenotypes in a population over time? |
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- Describe the mechanisms by which variation arises and is fixed (or lost) in a population over time.
- Calculate allele frequencies based on phenotypic or genotypic data for a population, and be able to explain the assumptions that make such a calculation possible.
- Model how random mating yields predicted genotype frequencies in Hardy-Weinberg Equilibrium (HWE), and how non-random mating affects allele and genotype frequencies.
- Test whether HWE has been reached in a population.
- Explain how inbreeding increases the number of homozygotes (and possibly disease) in comparison to HWE.
- Explain how natural selection and genetic drift can affect the elimination, maintenance or increase in frequency of various types of alleles (e.g. dominant, recessive, deleterious, beneficial) in a population.
- Interpret experiments to determine the relative influences of genes and the environment on a given phenotype.
- Describe how variation can be measured, and what can be done to distinguish genetic and environmental sources of variation.
- Interpret bioinformatics data to compare homologous genes in different species and infer relative degrees of evolutionary relatedness.
- Use comparative data from multiple species to identify which regions of a protein, pathway, regulatory system etc. are critical for function.
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Genetics of Model Organisms |
How do the results of molecular genetic studies in model organisms help us understand aspects of human genetics and genetic diseases? |
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- Justify why information on functions of human genes can often be acquired through studies of simple model organisms such as yeast, nematode worms, and fruit flies.
- Compare the benefits and limitations of using model organisms to study human genes and human genetic diseases.
- Identify specific cases where insights from model organisms have provided crucial insights into human disease.
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Methods and Tools in Genetics |
What experimental methods are commonly used to analyze gene structure, gene expression, gene function, and genetic variants? |
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- Explain reverse genetics and compare methods for generating specific mutations in the genome vs. generating phenocopies using techniques such as RNAi or morpholinos.
- Explain the method of SNP/STR mapping and interpret SNP/STR mapping data to pinpoint the chromosomal location of a human disease gene.
- Interpret complementation tests, including an assessment of the molecular interactions that might yield the results observed.
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Additionally, all GSA PREP and related resources promote proficiency in at
least one core competency:
Core Competencies (see Vision and Change) |
Students should be able to locate, read, and comprehend primary literature research papers on genetics topics. |
Students should be able to implement observational strategies to formulate a question. |
Students should be able to generate testable hypotheses. |
Students should be able to design an experiment using appropriate controls and appropriate sample sizes. |
Students should be able to gather and evaluate experimental evidence, including qualitative and quantitative data. |
Students should be able to apply statistical methods when analyzing their data, and use patterns to construct a model. |
Students should be able to generate and interpret graphs displaying experimental results. |
Students should be able to critique large data sets and use bioinformatics to assess genetics data. |
Students should be able to communicate experimental results effectively, including writing research papers and giving presentations. |
Students should be able to effectively explain genetics concepts to different audiences. |
Students should be able to tap into the interdisciplinary nature of science. |
Students should be able to identify and critique scientific issues relating to society or ethics. |
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