Genetic Environment Flashcards
What are the four main causes of disease?
Genetic
Environment
Combination/multi-factorial
Unknown
What three ways can disease be identified?
Laboratory studies
Family studies
Epidemiology
Define Heritability
This is the extent that observed differences are due to genes
How do we measure heritability?
Family studies (bigger the better)
Twin studies
Adoption Studies
Migrant Studies
What are the two types of twins?
Monozygotic (identical) twins share genes and environment
• Dizygotic (non-identical) twins share same environment but share the same amount of genetic information as any other sibling
What are the potential problems which arise with twin studies?
Monozygotic twins share more environment than dizygotic twins therefore they are more dependant on each other
Monozygotic twins may not have shared the same uterine environment (small differences)
What is the equation for phenotype?
Phenotype = genes + environment + (genes x environment)
Show this as the proper equation
H2 = Vg / Vg + Ve + V(gxe)
This is based across a whole population
Name me some infectious agents
Bacteria Viruses Fungi Yeast Protozoa Parasites Prions Tropism
Name me some modes of transmission
Droplet • Faeco-oral • Venereal • Blood • Water • Food • Vectors/Fomites
- Horizontal = to other people
- Vertical = to children
- Zoonoses = from animal
- Nosocomial = a disease orginating in a hospital
What diseases is smoking associated with?
Mutagenic – cancer
• Inflammation – chronic obstructive pulmonary disease
• Nicotinic receptors – increases blood pressure and heart rate
• Endothelial damage
• Carbon monoxide levels – intrauterine growth retardation
What diseases can alcohol abuse lead to?
- Acetaldehyde - carcinogenesis
- Increases oestrogen levels
- Decreases NAD levels - alters lipid metabolism • Reactive oxygen - damages lipid membranes
- Decreases vitamin B levels
- Depresses CNS function
- Teratogenic
What irritations can dust cause?
Asbestos - mesothelioma
Asthma
Hayfever
Name me some injuries from physical agents
• Mechanical injury (trauma) • Thermal injury – Hypothermia – Fever (Pyrexia) – Burn • Radiation – Ionising – Non-ionising (UV)
What does the Hardy-Weinberg Principle state?
that allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences.
