Genotype & Phenotype
Genotype
- This is our genetic makeup, the particular set of genes a person possess
- Everyone has a unique genotype (apart from MZ who share 100% of their DNA)
- On average, a individual has around 100,000 genes
- One genotype determines certain characteristics such as eye and hair colour
Phenotype
- The expression of the genes
- This is the characteristics of an individual determined by both their genes and how they are expressed in their environment
- An individual's genotype will determine how tall they could potentially growl however, environmental factors, such as nutrition will determine whether or not they reach their maximum height
- Additionally, an individual may be predisposed to a certain behaviour e.g. criminality but this behaviour may only be expressed if specific environmental factors are in place e.g. lack of money; mixing with the 'wrong' crowd
Worked example
Explain what is meant by a ‘genetic basis to behaviour’. [6 marks]
AO1 = 6 marks
For 5-6 marks the answer should clearly and concisely explain what the term means, giving examples and linking each example to explicitly to the role of genetics in explaining behaviour. Effective use of examples should be given to illustrate each point made. There should be confident use of terminology.
For 3-4 marks the answer should explain what a genetic basis to behaviour means with some use of examples. There may be some lack of expansion or development of ideas. There should be some use of terminology.
For 1-2 marks the answer will be only partially successful in identifying key ideas as to the role of genetics and behaviour. Terminology will be sparse and there may be some vagueness or ambiguity to the response.
Possible answer content could include:
- A genetic basis to behaviour is part of the Biological Approach, rooting behaviours in physical/physiological contexts, including evolutionary psychology
- Both physical and internal (e.g. mental) characteristics are inherited. Traits present in current behaviour may be present as evolutionary processes have selected the most adaptable and useful genes for continued survival
- Some traits are innate rather than being the product of environmental influences e.g. physical characteristics such as eye colour, as well as ‘invisible’ traits e.g. having an innate predisposition for musical ability or sporting prowess
- Everyone has a genotype which comprises their total set of inherited genes from both parents
- The phenotype consists of the ways in which the genotype is expressed and may be influenced by environmental factors e.g. upbringing, nutrition, education
