Genetics

Question 1

Essential understandings

Answer 1

• patterns of behaviourcan be inherited as a means of adapting to our environment &increasing our chance of survival
• behaviour is the interaction of genetic inheritance & environmental factors
• important ethical considerations in the use of genetic research and testing
• technology has furthered our understanding of the role of genetics on behaviour

Psychologists are interested in behavioural genetics

• understanding both how genetics and environment influence variations in human behaviour

Question 2

Diathesis stress model

Answer 2

attempts to explain behaviour as a predispositional genetic vulnerability expressed as a result of stress from life experiences

Question 3

Epigenetics

Answer 3

• argues that in order for a behaviour to occur, genes must be ‘expressed’
  
  • genetic expression is a complex chemical reaction to environmental or physiological changes that allow a gene to ‘do its job’
    
    • important to know that environmental factors such as stress, exercise or diet may result in genetic expression, or the lack of genetic expression
      
      • this means that an individual may have a gene that could lead to a behaviour, but if the gene is never expressed, than this behaviour will not occur

Question 4

Methods of genetic research

Answer 4

• twin studies
• Comparing adopted children to adoptive parents and siblings, and biological parents and siblings, infering environmental or genetic influence if children are more similar to either biological or adoptive.
• adoption studies
  
  • Comparing adopted children to adoptive parents and siblings, and biological parents and siblings, infering environmental or genetic influence if children are more similar to either biological or adoptive.
• family studies
  
  • Uses principle of genetic relatedness but compares relatives on a broader scale and across generations
• molecular genetics
  
  • Genetic mapping and identifying particular genes + alleles in an individual, where genetic variants are compared with observable behaviour, used to identify specific genes responsible for behaviour

Question 5

5-HTT

Answer 5

• gene plays a role in the serotonin pathways that scientists believe are involved in controlling mood, emotions, aggression, sleep
  Responsible for the coding of transporter proteins in axon terminals specific to the re-uptake of serotonin after an action potential.
• number of serotonin transporters determines the length of time that serotonin will stay in the synaptic cleft before re-uptake

The 5-HTT gene has 2 alleles ’s’ (mutated) and a ‘l’ version

• where the s version produces less serotonin transporter proteins than the l version.

Those with an allele combination including at least one ’s’ allele have the higher rates of depression than those with two ‘l’ alleles

• ss is highest