Biological perspective
Emphasis is on physical or
neurological factors and how they
impact behavior, thought, and
emotion
Genetics
Nervous systems
Neurons
Neurotransmitters
Brain structures
Endocrine system (hormones)
Genetics
We have 23 pairs of chromosomes
Fathers contribute one chromosome and mothers
contribute the other chromosome in the pair
Chromosomes contain genes – over 1,000 genes
per chromosome
Individual attributes are determined by a single or
multiple pairs (polygenic) of genes
Only 5 – 10% of genes are active in any given cell
Activity in cells changes in different situations
Genes act differently in different cells
Genes may be switched on and off during different times in our
lives
1/5 of genes are switched on at any given time
Basic genetic terms
Genotype – gene pattern –
indicated by capital and lower case
letters (ie., BB, Bb)
Phenotype – outward, visual
expression of the gene (ie., brown
eyes, blue eyes)
More genetic terms
Homozygous pair – two genes in
the pair that are either both
dominant or both recessive (ie., BB
or bb)
Heterozygous pair – Pair of genes
are made up of one dominant and
one recessive gene (ie., Bb)
More genetic terms
Dominant gene – produces its effect
regardless if in a homozygous or
heterozygous pair (represented by
a capital letter)
Recessive gene – produces its effect
only when two recessive genes are
present in a pair (represented by a
lower case letter)
Punnett’s square
You can roughly
determine genetic
makeup of your
children by
crossing the
B b
b
*
*
genetic
contribution of the
father with the
mother
*Each cell
represents 25%
possibility
b
*
*
Genetic example – ie., Freckles
(Dominant)/ Clear skin (recessive)
Nervous System
Nervous system
Central nervous system – brain and
spinal cord
Peripheral nervous system –
connects the brain and spinal cord
to the rest of the body (tissues,
organs, muscles…)
Somatic nervous system – controls
voluntary muscles
Autonomic nervous system