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Psychology Midterm Cheat Sheet by

Biological and Cognitive Bases of Psychology

Genetic and Evolution

Charles Darwin - Theory of evolution
Natural Selection is a theory developed through his observ­ations of the fitness of species charac­ter­istics to its enviro­nment
Natural selection and fitness
Animals that have certain traits that get an advantage
Evolution is a slow process
Fitness - organisms that are going to survive
not good enough that you survive, must pass traits on

Survival Adaptation

obtain food for yourself
physical traits
all these adaptation make your chance greater for survival

Reprod­uctive adaptation

passing on genes to the next genera­tions
some genes less useful, but are needed for reprod­uction
make animals more desirable to the opposite sex
example: abs, plumage of peacocks


are then passed on with greater frequency due to their associ­ation with greater mating sucess
when males fight with other males to win over the female
pressure on males to succeed
not always a physical deal - example: Satin bird

Inters­exual Selection

in this process, if members of one sex are attracted to certain qualities in mates
example: brilliant plumagem, signs of good health, or even intell­igence
female can select the winner
which one has the best genes/­traits

Evolution of Modern Humans

first brain cell: 700 mya
cell moving towards heat or light
starts getting collection of brain cell to work together and produce basic brain function
first brain cell: 250 mya
first primate brain: 7 mya
humans and chimpa­nzees share common ancestors about 7 million years ago
modern humans are relatively recent in geological record
substa­ntial physio­logical and cognitive changes compared to earlier species

Austra­lop­ith­ecus: Our distant ancestor

irst primate to show distinctly human charac­ter­istics
walk on two legs, chimpanzee walk on 2 but not very well
spending a lot of time on the ground than in trees on 2 legs
how smart, overall: as a modern chimpanzee
judged by tool use and tool making
chimpanzee can use tools but do not make them
austra­lop­ith­ecus, could also not make them, but could use them

Hominids: the earliest humans

homo habilis (handy human) manufa­cture simple stone tools
homo erectus (upright human) around on earth longer than we have been around
neande­rthals - better stone tools and higher intell­igence

Evolution of Modern Humans

adapta­tions to a changing enviro­nment
change in diet -> smaller facial muscles and teeth
not just focusing on meat but now fruit
allows cooking to soften the meal, we don't have big teeth = everything gets smaller
smaller facial muscles and teeth -> greater range of vocali­zation -> language
small changes to mouth, more room for vocal track
produce language
cognitive ability
better tool making ability
social organi­zation -> culture
from early to modern humans, brain size and cognitive ability increases


every cell in an organisms body contains the genetic blueprint for that organism
human body -> cell -> chromo­somes -> DNA -> Gene
gene -> protein -> expression
genotype - blueprint examples: blue eyes, plans is housed the gene themselves
phenotype - the physical expres­sions of the genotype example: person has blue eyes
complex things break down to simple ideas
four basic bases, which are linked to each other
adenine bonds with thymine
cytosine bonds with quanine

Gene to protein

the sequence of bases in gene determines which amino acids are used to build the specified protein
sequences of bases code for specific amino acids
bases -> amino acids -> proteins

amino acids to protein

amino acids
linked together by a peptide bond
a polype­ptide amino acids chain forms a protein
proteins are required to maintain cell function
proteins typically degrade within days
DNA ->mRNA -> Amino acid chain
transc­ription and traslation
mRNA leaves nucleus and moves to endopl­asmic reticulum
translates into different amino acids that need to be built
ribosomes move along translates the mRNA and codes for amino acids
codon codes for a specific amino acid
amino acids are chained together to make protein
golgi body is packaged into vesicles and transp­orted into different parts of the cell

Genetic techniques

introduce or remove genes of an embryo
knock in / knock out : Fur colour in mice, gene for genetic disorder,
knock in : mouse that is supposed to have white fur, introduce genes for black fur
knock out : turn off gene
genetic disorder, develop treatment, common practice in neuros­cience

Animals model for human disorders

the mammalian brain is struct­urally similar across species
animals models used to mimic human diseases such as Alzhei­mer's and Parkin­son's
introduce a gene into a rat then you can test treatment and you are not dealing with human subjects

Genetic techniques

"maze bright­" and "maze dull rats"
selective breeding
maze bright = rats that picked up learning the maze well
maze dull = rats that did not learn it well
only breed maze bright
generation later keep smart rat together and non-smart together

The human genome project

completed in 2003
human genetic code contains less than 30,000 genes
4 bases that make it all up
to what degree are human abilites geneti­cally determined vs. linked enviro­nement
genetics vs. what are you doing

Identical twins

studying genetic disorders in identical twins
share the same genetic code
identical twins raised apart share many of the same physical and person­ality traits
indivi­duals experi­ences
measures data of identical twins who were raised apart and live in different enviro­nment
can it be explained by genes or enviro­nment
you tend to see the same traits in this twin which is a strong genetic link
behavi­oural genetics are used to study genetic influence on a host of different behaviours
strong influence of genetics but does not answer the whole story: learning disabi­lites, mental disabi­lites


how a person experience can effect their gene
genes can explain variation between certain traits behaviours but not all
epigenetic drift - differ­ences
when you observe the twin boys at a genetic level they are almost identical as well
older in lifem you start to see differ­ences. similarity start to become epigenetic drift because the different experinces they are having in life

Epigenetic mechanisms

having their effects in this process
DNA transc­ription
histone modifi­cation - DNA does not get transc­ribed like it should. results in the protein that was not intended
DNA modifi­cation
they all represent how the plan can be changed
critical during develo­pment when genes have to turn on and off at a precise interval
silent genes to let it develop into a mature gene

Enviro­nmental effects on the genome

diseases linked to enviro­nmental exposure are difficult to track
different people respond differ­ently
person may not have a geneti­cally exposed to lung cancer but if they take up smoking


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