Lesson 7: Genetics And Biological Structures

Question 1

Key assumptions of genetics and biological structures

Answer 1

• Behaviour has evolved through evolutionary adaptation
• The genes an individual possesses influence their behaviour
• The biological examination of animals can provide useful information about human behaviour
• Biological structures and neurochemistry control and influence our reactions to the environment

Question 2

Evolution

Answer 2

According to Charles Darwin, our behaviour has adapted and changed over time through natural selection. This is where profitable behaviours are selected in mates and therefore reproduced. Over time, advantageous behaviours will continue which will continually increase our ability to survive.

Question 3

The influence of genetics

Answer 3

• Heredity refers to the idea that characteristics are passed on from one generation to the next through our genetics. These characteristics can be physical or psychological. To examine the extent to which genes influence behaviour, work is often carried out on pairs of twins. These studies often involve comparing the likelihood of a behaviour occurring in identical twins to the likelihood of the beha jour occurring among non-identical twins. If the MZ twins show a higher concordance rate then there is argued to be a genetic component.
• It is very rare however, that the concordance rate for MZ twins is 100%. This suggests that, although there may be a genetic influence, some behaviours could be a mix of both genetics and environment.

Question 4

Genotype

Answer 4

• refers to the genes an individual possesses i.e. an individual’s genetic make-up

Question 5

Phenotype

Answer 5

• refers to the observable traits shown by an individual that are due to the combined effect of genes and environment

Question 6

The central nervous system

Answer 6

• This comprises of the brain and spinal cord which act as the centre from whcih the individual is controlled e.g. through the cognitive processing of the brain

Question 7

The peripheral nervous system

Answer 7

• This comprises of the somatic nervous system and autonomic nervous system. The somatic nervous system comprises the muscles attached to the skeleton and is therefore pivotal for movement. The autonomic nervous system oversees bodily organs and is involved in the fight or flight response.

Question 8

The endocrine system

Answer 8

• The endocrine system maintains levels of hormones in the blood that are released by glands. The most important gland is the pituitary gland which is located in the brain. This is sometimes called the master gland because it instructs the other glands in the body to secrete hormones when necessary.