Biology and Behaviour

deoxyribonucleic acid

a package of DNA

the basic unit of heredity / instructions for making proteins or controls other genes

a complete set of genetic materials in an organism

a different version of a gene that influences the same trait but leads to different outcomes

the genetic material an individual inherits

the observable expression of the genotype e.g. height / behaviour

- Information from a gene is used to produce protein
The combination of genes switched on and off will determine the cell - - The combination of genes switched on and off will contribute to phenotype
- Role of regulator genes
Role of external factors

cells that have the ability to express all genes

can only express genes associated with specialisation

- 46 chromosomes = 23 pairs (23 from each parent)
- Every individual has 2 copies of each gene

via gametes

members of a pair of chromosomes sometimes swap sections of DNA

a change in a section of DNA - caused by spontaneous errors / environmental factors - mostly harmful but sometimes can be due to evolution

· Dominant allele- expressed if present
Recessive allele- not expressed if a dominant allele is present

two of the same alleles for a trait

two different alleles for a trait

- Y chromosome smaller and contains less genes
- Recessive allele on X chromosome might not have a dominant allele on Y to override it
- Inherited disorders and conditions caused by recessive alleles on the X chromosome in XY individuals

- Parents genes influence their own abilities and prepaderenes, which influence the environment they provide for their children
Same genotype can result in different phenotypes in different environments \ • Each child evokes certain kinds of
responses from others
o Even siblings experience different
environments due to their own
behaviours
• Children shape their own
environment

· Recessive disorder, defective gene on chromosome 12
· Individuals with tow recessive copies are unable to metabolize phenylamine- builds up In the brain and blood
· Without treatment = PKU can affect nervous system and brain - learning disabilities and other symptoms
Management = early diagnosis - restricted diet

how genetic and environmental factors combine to influence individual differences in behavior, personality, cognition, and mental health

1. the closer two people are genetically (like identical twins), the
more alike they are expected to be if traits influenced strongly by
genetics
2. shared experiences and surroundings (environment) influence
development in a way that promotes similarity among those
raised together.

A measure of how
much of the variation
in a trait within a
population is due to
genetic differences. - between 0-1

Heritability estimate applies only to a particular population living in a
particular environment.
o Manly samples of Western, educated, industrialized, rich, and democratic
(WEIRD) participants