The biological approach

• What is a genotype?


  The combination of all the genes within each cell of an individual. Genotype dictates characteristics such as hair & eye colour. Unique to each individual.
• What is a phenotype?


  The behaviour and physical structure of an individual arising from an interaction between their genotype & their environment.
• What is the difference between monozygotic and dizygotic twins?

  Monozygotic: identical

  Dizygotic: non-identical
• How many pairs of chromosomes are there in body cells?

  23
• Name the major endocrine glands.

  • Pituitary (P)
  • Hypothalamus (H)
  • Thyroid (TR)
  • Thymus (TM)
  • Adrenals (A)
  • Pancreas (P)
  • Ovaries (O)
  • Testes (T)
• What is the function of adrenaline?

  Fight or flight response.
• What is the function of testosterone?

  Testosterone regulates sex drive, muscle size and strength, and development of male secondary sexual characteristics.
• What is the function of oestrogen?

  Regulates the menstrual cycle, pregnancy and menopause, along with development of female secondary sexual characteristics.
• What is the function of melatonin?

  Regulating sleep and wake cycles.
• What is the function of oxytocin?

  Aids contraction of the womb during childbirth and aids in lactation.
• What is the function of insulin?

  Facilitates uptake of glucose into cells, thus lowering blood sugar levels.
• What is the function of thyroxine?

  Regulating metabolism, energy and growth.
• Describe what happens during the fight or flight response in the body.

  • The ANS changes from parasympathetic to sympathetic activation. Heart rate increases and pupils dilate.
  • The pituitary gland releases the adrenocorticotrophic hormone (ACTH)
  • ACTH stimulates the adrenal glands causing them to secrete adrenaline into the bloodstream
  • These hormones prepare the body for the fight or flight response by boosting the supply of oxygen and glucose to the brain and muscles
• What does the fight or flight response being maladaptive mean?

  Not adjusted adequately or appropriately to the environment or situation. Evolved when stressors were immediate & short lived. Unlike stressors of today which are prolonged. Our bodies cannot cope with prolonged activation of the sympathetic pathway without a negative impact on our health. Explains why when we are stressed we may lose weight or become ill/take longer to heal.
• What does the fight or flight response being androcentric mean?

  Focused or centred on men. Fight or flight often reflects how males will react to stressful encounters. Taylor et al (2000) suggests that women are more likely to 'tend and befriend' where they are more likely to protect their offspring or form allegiances with other women.
• Label the neurone.

  .

  A) Cell body

  B) Dendrite

  C) Nucleus

  D) Axon

  E) Nerve ending

  
• How do synapses work?

  • Nerve impulses cannot cross synapses - info is passes from one to the next using neurotransmitters
  • When an impulse arrives, the chemical messenger is released into the synapse
  • It diffuses across the synapse
  • On the other side, the neurotransmitter binds with a receptor molecule
  • As it binds it stimulates a new nerve impulse in the next neurone
• What are neurotransmitters stored in?

  Vesicles
• What is a gene?

  A part of the chromosome of an organism that caries information in the form of DNA
• What are excitatory neurotransmitters?

  The "on switch". Cause excitation of post-synaptic neuron by increasing its positive charge & making it more likely to fire. It causes an electrical charge in the membrane of that cell resulting in excitatory post synaptic potential (EPSP) making it more likely to fire.
• What are inhibitory neurotransmitters?

  The "off switch". Generally, calm the mind & body, including sleep and filtering out unnecessary excitatory signals. An inhibitory neurotransmitter binding with a postsynaptic receptor results in an inhibitory post synaptic potential (IPSP) so it is less likely to fire.
• It is possible to receive both ESPS's and ISPS's at the same time. Whether the cell fires or not is determined by adding up the excitatory and the inhibitory synaptic input. The net sum of this calculation (summation) determines whether the cell fires.
• What are advantages of the biological approach?

  • Practical applications - Insights from genetics and biochemistry help us to understand the causes of disorders which in turn helps us find drug treatments. Helps people live relatively normal lives.
  • Scientific - uses precise and reliable methods. Experimental studies take place in highly controlled environments.
• What are the disadvantages of the biological approach?

  • Causal conclusions - if a drug reduces symptoms of a disorder it is assumed that neurotransmitter causes the disorder, however association does not mean that it is a cause
  • Deterministic - suggests human behaviour isn't associated with free will. Has implications for wider society e.g. legal system.
  • Reductionist - reduces complex behaviour down into simple biological components & ignores other possible factors.
• What are twin studies?

  Studies that compare the similarities and differences between monozygotic and dizygotic twins to determine the relative contributions of genetics and environment to certain traits or conditions.
• What are family studies?

  Look at how common a behaviour is in the general public compared to how common a behaviour is within a family. If there is a higher rate within a family, then it might be genetic.
• What are adoption studies?

  Studies that examine the effects of genetics and environment by comparing adopted individuals with their biological and adoptive families. Similarities suggest genetic inheritance.
• What is selective breeding?


  Breeding two individuals with a certain characteristic to see if their off-spring inherits the characteristic.