brain learning and motivation: brain behaviour- genetics

Question 1

mendalean genetics

Answer 1

19th century monk
demonstrated inheritance occurs through genes
• Genes are aligned along chromosomes (strands of genes) and come in pairs
• A gene is a por1on of a chromosome and is composed of deoxyribonucleic acid (DNA)

Question 2

DNA

Answer 2

serves as a model for the synthesis of ribonucleic acid (RNA)

Question 3

RNA

Answer 3

is a single strand chemical that can serve as a template/ model for the synthesis of proteins

Question 4

proteins

Answer 4

determine the development of the body by:
Forming part of the structure of the body
Serving as enzymes, biological catalysts that
regulate chemical reac1ons in the body

Question 5

homozygous for a gene

Answer 5

means that a person has an iden1cal pair of genes on the two chromosomes

Question 6

heterozygous for a gene

Answer 6

means that a person has an unmatched pair of genes on the two chromosomes

Question 7

how many genes control a characteristic

Answer 7

not just one

– Eye colour: at least 10 genes (Liu et al, 2010) – Height: at least 180 genes (Alen et al, 2010)

Question 8

gene expression

Answer 8

• Some genes are only expressed partly: in some cells and not others or only under certain circumstances

Question 9

types of genes

Answer 9

autosomal: all genes except for sex linked

sex linked genes: located on sex chromosomes

Question 10

human x chromosome

Answer 10

has genes for approx 15000 proteins

Question 11

sexlinked characteristics

Answer 11

usually refer to those on x chromosome e.g. red green colour blindness

Question 12

genes change in several ways…

Answer 12

mutation
microduplication
microdeletion

Question 13

mutation

Answer 13

a heritable change in a DNA molecule

Question 14

microduplication/microdeletion

Answer 14

part of a chromosome that might appear once might appear twice or not at all

Question 15

epigenetics

Answer 15

a field that is concerned with changes in gene expression without the modifica1on of the DNA sequence

Epigene1c differences are a likely explana1on for differences between monozygo1c “iden1cal” twins

Question 16

gene activity

Answer 16

some genes are only active at specific times in ones life or during the day

eg a malnourished mother would have pups who would easily consev energy but this could lead to obesity in the pups

Question 17

how experiences alter the activity of genes

Answer 17

What you do at any moment not only affects you now, but produces epigene1c effects that alter gene expressions for a longer period of 1me

Question 18

heredity and environment

Answer 18

• Almost all behaviors have both a gene1c component and an environmental component
• Researchers study monozygo1c (“from one egg”) and fraternal (“from two eggs”) twins to infer contribu1ons of heredity and environment
• Researchers also study adopted children and their resemblance to their biological parents to infer hereditary influences

Question 19

enviromental factors influence Schizophrenia

Answer 19

in those at risk of developing Schizophrenia, environmental factors such as stress influences its development
 Study of predisposed adopted children in psychologically healthy families vs. adopted children with families that were disturbed
 In healthy families, none became psycho1c
 In disturbed families, 11 percent of the children became psycho1c and 41 percent had severe psychological disorders

Question 20

heritability

Answer 20

refers to how much characteris1cs depend on gene1c differences
Researchers have found evidence for heritability in almost every behavior they have tested
• Heritability of a certain trait is specific to a given popula1on
• Strong environmental influences may cause gene1c influences to have less of an effect

Question 21

Traits with a strong hereditary influence

Answer 21

by modified by environmental interven1on
– e.g., PKU: a gene1c inability to metabolize the amino acid phenylketonuria
– Environmental interven1ons (a special diet) can modify PKU

Question 22

how genes influence behaviour

Answer 22

genes don’t directly influence behaviour

Question 23

heredity and environment

Answer 23

Genes produce proteins that increase the probability that a behavior will develop under certain circumstances
• Genes can also have an indirect affect
– Genes can alter your environment by producing behaviors or traits that alter how people in your environment react to you

Question 24

the evolution of behaviour

Answer 24

Evolu1on refers to a change in the frequency of various genes in a popula1on over genera1ons
regardless if the characteristic is helpful or harmful to the population

Question 25

evolution attempts to answer two questions

Answer 25

– How did some species evolve?

– How do species evolve?

Question 26

how species did evolve

Answer 26

involves the tentative production of evolutionary trees

Question 27

how species do evolve

Answer 27

rests upon these assumptions:
Offspring generally resemble their parents for gene1c reasons
– Muta1ons, recombina1on, and microduplica1ons of genes introduce new heritable varia1ons
– Certain individuals successfully reproduce more than others do

Question 28

artificial selection

Answer 28

refers to:

choosing individuals with desired traits and making them parents of the next genera1on

Question 29

natural selection

Answer 29

According to Darwin, nature also selects, and successful individuals’ genes will be prevalent in later genera1ons

Question 30

common misconceptions about evolution:

Answer 30

– Lamarckian evolu1on: “The use or disuse of some structure or behavior causes an increase or decrease in that structure/behavior.”
– “Humans have stopped evolving.”
– “Evolu1on means improvement.”
– “Evolu1on acts to benefit the individual or the species.”

Question 31

evolutionary psychology

Answer 31

focusses upon
func1onal and evolu1onary explana1ons of how behaviors evolved
assumes that:
Assumes that behaviors characteris1c of a species have arisen through natural selec1on and provide a survival advantage

Question 32

Altruistic behaviour

Answer 32

describes behaviour that benefits one individual a lot more than another

hard to find altruism outside of humans

Question 33

group selection

Answer 33

is a controversial hypothesis that states that altruis1c groups survive beUer than less coopera1ve ones

Question 34

kin selection

Answer 34

the favored explana1on: selec1on for a gene that benefit’s the individual’s rela1ves

Question 35

comparative psychology

Answer 35

the use of animals to study behaviour and the brain

Question 36

comparative psychology: animal research

Answer 36

has told us most o what we know about the nervous system

though poses an ethical dilemma

Question 37

reasons for animal research

Answer 37

the underlying mechanisms of behaviour are similar across species and often easier to stud in non-human species
information learned form animals sheds light on human evolution
tells us about animal evolution swell
some experiments cannot use humans for legal or ethical reasons

Question 38

examples of animal research

Answer 38

squid axons: human axons are too small
visual cortex in the cat
Pleasure centres in the brain and dopamine