L10 - An Introduction to Genetics Flashcards
What is Molecular genetics?
The chemical nature of the gene itself. Focuses on molecular mechanisms of how genetic information is encoded, replicated and expressed. It includes the cellular processes of replication, transcription, and translation. As well as gene regulation. The focus in molecular genetics is the gene and its structure, organisation and function.
What is Transmission genetics?
The principles of heredity and how traits are passed from one generation to another. Often used to study disease. This subdiscipline addresses the relationships between chromosomes and heredity, the arrangement of genes on chromosomes, and gene mapping. The focus is on an individual organism; how it inherits its genetic makeup and how it passes its genes onto the next generation.
What is Population genetics?
Explores the genetic composition of populations and how the composition changes geographically and with the passage of time. Can be applied to conservation, or used to study evolution.
What are genes?
a ‘unit of information that helps determine a trait’
What are alleles?
Different forms of genes
What are genes the fundamental unit of?
Heredity, they are inherited from parent to offspring and they allow evolution to occur. All organism share a common coding system for their genes - they have a common ancestor. Studying genes in one organism can tell us about its function in another.
How many genes do humans have?
~20,000 genes. Alterations in just one of these can have a huge impact on our lives. Our genes (along with environmental factors) influence our phenotype, the ‘appearance or manifestation of a characteristic’. Genetic info is carried in DNA and (in a few viruses), in RNA.
Why is genetics important?
Important to individuals, to society, and to the study of biology.
- Why is genetics important? - Medicine
Medicine - genes affect our susceptibility to many diseases and disorders. E.g. Diastrophic dysplasia, a hereditary growth disorder that results in curved bones, short limbs, and hand deformities. Diastrophic dysplasia is due to the defect in the SL26A2 gene on chromosome 5.
- Why is genetics important? - Genetic testing and genetic counselling
Genetic testing and genetic counselling provide info to those concerned about genetic diseases or traits. Genetic testing - recognising the potential for a genetic condition at an early stage e.g. pre-natal test for down syndrome. Genetic counselling - education process providing information to patients with genetic disorders and those who are concerned about hereditary conditions
- Why is genetics important? - Evolution of superbugs
E.g. antibiotic resistance. Here, routine use of antibiotics kills bacteria without a resistance gene e.g. completely drug resistant forms of TB now exist. The spread of resistance can occur quickly due to gene transfer on plasmids. Creates a resistant population.
- Why is genetics important? - Medicine and evolution
E.g. Evolution of viruses, an evolutionary tree of COVID-19 variants. Phylogenetically very different and new variants. The vaccines are based on sequencing the viral RNA. This means that the vaccine can be easily modified if the viruses mutate to escape control by the vaccine.
- Why is genetics important? - Agriculture
We’ve been selective breeding (artificial selection) for ~10,000. In the 1950s/60s, the third agricultural revolution developed high yield crops and prevented mass starvation, but has no led to biodiversity crisis. Genetic modification (artificially inserting genes from one species into another) is controversial, especially in agriculture. GM is important in medicine e.g. insulin production.
- Why is genetics important? - Forensics
DNA profile analyses are often key in modern criminal cases, police forces have their own DNA databases and will sample suspects. Police have also used DNA databases such as 23andme and ancestry.com to find familial DNA matches. E.g. The rape and murder of Angie Dodge in Idaho, was solved after more than 20 years
- Why is genetics important? - Understanding Evolution
Ancestry testing, understanding human (pre) history and evolution. E.g. upper Paleolithic human Oase 2 had around 7.3% Neanderthal DNA (from an ancestor 4-6 generations back)
- Why is genetics important? - Racism, Sexism, Society
Genetics have been used to justify racism and sexism, sometimes to the extreme. Non-western people and cultures have often been considered to be ‘less evolved’, and results interpreted accordingly. Some indigenous people have been exploited. Some medicines have been incorrectly applied to different racial groups based on unsubstantiated genetic differences. Some medicines have been incorrectly applied to different racial groups based on unsubstantiated genetic differences. Science, history etc are all interpreted in the context of our cultures and prior, often subconscious, beliefs.
- Why is genetics important? - Conservation
Genetic diversity is hugely important for conservation : Understanding barriers to movement, inbreeding depression, captive breeding, reintroductions, hybridisation. Hedgehog are a species in severe decline, conservation genetics could help to understand barriers to movement and potential issues with inbreeding. Scottish wildcat, a species threatened by hybridisation with domestic cats, conservation program can use genetic methods to select purebred wildcats to breed from.
