PSYCH 1XX3 EXAM SCRIPT 2026/2027 QUESTIONS AND
SOLUTIONS RATED A+
✔✔Sex Chromosomes - ✔✔Females: XX
Males: XY
✔✔Expression of Genetic Information - ✔✔1. Dominant-Recessive Inheritance
2. Polygenic Inheritance
3. Codominance
4. Sex-Linked Inheritance
✔✔Genotype - ✔✔inherited genes
✔✔Phenotype - ✔✔expresses characteristics of the inherited genes
✔✔Dominant-Recessive Inheritance - ✔✔dominant allele is expressed in the
phenotype; recessive allele is not expressed but still heritable
✔✔Homozygous - ✔✔when two alleles have the same effect on the phenotype; dom +
dom or recessive + recessive
✔✔Heterozygous - ✔✔when two alleles have a different effect on the phenotype; dom +
recessive
✔✔Polygenic Inheritance - ✔✔when the expression of a trait is determined by the
inheritance of multiple genes; no single gene can account for complex behaviours
ex. height, weight
✔✔Codominance - ✔✔two dominant alleles are both fully and equally expressed to
produce a phenotype that is a compromise between the two genes
ex. ABO blood type proteins in humans
(A and B are both dominant, O is recessive; AB are both expressed so blood type is AB)
✔✔Canalization Principle - ✔✔all individuals are restricted to a similar phenotype
despite variations in the environment; genotype restricts the phenotype to a small
number of possible developmental outcomes; some developmental processes are
buffered against environmental variability
✔✔Range of Reaction Principle - ✔✔our genotype restricts us to a range of possible
phenotypes whose expression is dependent on environmental conditions
✔✔Gene Influence on Preferred Environment - ✔✔1. Passive Correlations; childhood
2. Evocative Correlations; throughout life
3. Active Correlations; adulthood
,✔✔Passive Correlations - ✔✔the environment that parents choose to raise their child in
was influenced by the parent's own genes
✔✔Evocative Correlations - ✔✔the traits that we have inherited affect how others react
to and behave towards us
✔✔Active Correlations - ✔✔our genotypes influence the kinds of environments that we
seek
✔✔Critical Period - ✔✔specific time window when certain experiences are required for
normal development
ex. 4 week for vision
✔✔Types of Brain Growth - ✔✔1. Experience-Expectant Brain Growth
2. Experience-Dependent Brain Growth
✔✔Experience-Expectant Brain Growth - ✔✔our brains have evolved to expect a
certain amount of environmental input, an with this input, our brains develop normally
✔✔Experience-Dependent Brain Growth - ✔✔our brains develop according to our own
experiences
✔✔Sensitive Periods - ✔✔brain maintains some capacity for change and growth in
adulthood; flexibility in the timing and type of stimulation required for normal
development
✔✔Adaptations - ✔✔functional traits or characteristics that help an individual survive
and reproduce in their environment; perform a specific function
✔✔Higher Mental Processes - ✔✔- selective attention
- memory encoding
- memory retrieval
✔✔Components of Natural Selection - ✔✔1. Individual Differences (variation)
2. Differential Reproduction
3. Heritability
✔✔Individual Differences - ✔✔the variation among individuals on a characteristic
✔✔Differential Reproduction - ✔✔chance of fitness is more or less depending on
characteristics
, ✔✔Heritability - ✔✔the ability of a trait to be passed down genetically from one
generation to the next
✔✔Stabilizing Selection - ✔✔selects against any traits that are dissimilar from species-
typical adaptive design; keeps traits stable for generations
✔✔Sexual Selection - ✔✔type of natural selection that selects for behaviours and traits
that increase the likelihood of reproducing
✔✔Modes of Sexual Selection - ✔✔1. Female Choice
2. Success in Combat
✔✔Sexually Selected Traits - ✔✔differs between the sexes and specific to breeding
season
✔✔Female Choice - ✔✔picking males with greatest resistance to locally prevalent
diseases
ex. in humans: deep voice, facial structure
✔✔Social Behaviours - ✔✔1. Cooperation
2. Selfishness
3. Altruism
4. Spite
✔✔Cooperation - ✔✔sometimes reaps more benefit to you than selfishness; cost to you
< benefit of your action
ex. geese foraging in groups
✔✔Altruism - ✔✔helping others survive and reproduce at a cost to yourself
✔✔Eusocial Hymenoptera - ✔✔includes all ants, some bees, and some wasps; most
individuals spend their lives serving the colony without reproducing
✔✔Direct Fitness - ✔✔fitness from personal reproduction
✔✔Indirect Fitness - ✔✔fitness from the reproduction of close genetic relatives
✔✔Inclusive Fitness - ✔✔direct fitness + indirect fitness
✔✔Hamilton's Rule - ✔✔rB>C; B is the benefit (in number of offspring equivalents)
gained by the recipient of the altruism, C is the cost (in number of offspring equivalents)
suffered by the donor while undertaking the altruistic behaviour, and r is the genetic
relatedness of the altruist to the beneficiary
SOLUTIONS RATED A+
✔✔Sex Chromosomes - ✔✔Females: XX
Males: XY
✔✔Expression of Genetic Information - ✔✔1. Dominant-Recessive Inheritance
2. Polygenic Inheritance
3. Codominance
4. Sex-Linked Inheritance
✔✔Genotype - ✔✔inherited genes
✔✔Phenotype - ✔✔expresses characteristics of the inherited genes
✔✔Dominant-Recessive Inheritance - ✔✔dominant allele is expressed in the
phenotype; recessive allele is not expressed but still heritable
✔✔Homozygous - ✔✔when two alleles have the same effect on the phenotype; dom +
dom or recessive + recessive
✔✔Heterozygous - ✔✔when two alleles have a different effect on the phenotype; dom +
recessive
✔✔Polygenic Inheritance - ✔✔when the expression of a trait is determined by the
inheritance of multiple genes; no single gene can account for complex behaviours
ex. height, weight
✔✔Codominance - ✔✔two dominant alleles are both fully and equally expressed to
produce a phenotype that is a compromise between the two genes
ex. ABO blood type proteins in humans
(A and B are both dominant, O is recessive; AB are both expressed so blood type is AB)
✔✔Canalization Principle - ✔✔all individuals are restricted to a similar phenotype
despite variations in the environment; genotype restricts the phenotype to a small
number of possible developmental outcomes; some developmental processes are
buffered against environmental variability
✔✔Range of Reaction Principle - ✔✔our genotype restricts us to a range of possible
phenotypes whose expression is dependent on environmental conditions
✔✔Gene Influence on Preferred Environment - ✔✔1. Passive Correlations; childhood
2. Evocative Correlations; throughout life
3. Active Correlations; adulthood
,✔✔Passive Correlations - ✔✔the environment that parents choose to raise their child in
was influenced by the parent's own genes
✔✔Evocative Correlations - ✔✔the traits that we have inherited affect how others react
to and behave towards us
✔✔Active Correlations - ✔✔our genotypes influence the kinds of environments that we
seek
✔✔Critical Period - ✔✔specific time window when certain experiences are required for
normal development
ex. 4 week for vision
✔✔Types of Brain Growth - ✔✔1. Experience-Expectant Brain Growth
2. Experience-Dependent Brain Growth
✔✔Experience-Expectant Brain Growth - ✔✔our brains have evolved to expect a
certain amount of environmental input, an with this input, our brains develop normally
✔✔Experience-Dependent Brain Growth - ✔✔our brains develop according to our own
experiences
✔✔Sensitive Periods - ✔✔brain maintains some capacity for change and growth in
adulthood; flexibility in the timing and type of stimulation required for normal
development
✔✔Adaptations - ✔✔functional traits or characteristics that help an individual survive
and reproduce in their environment; perform a specific function
✔✔Higher Mental Processes - ✔✔- selective attention
- memory encoding
- memory retrieval
✔✔Components of Natural Selection - ✔✔1. Individual Differences (variation)
2. Differential Reproduction
3. Heritability
✔✔Individual Differences - ✔✔the variation among individuals on a characteristic
✔✔Differential Reproduction - ✔✔chance of fitness is more or less depending on
characteristics
, ✔✔Heritability - ✔✔the ability of a trait to be passed down genetically from one
generation to the next
✔✔Stabilizing Selection - ✔✔selects against any traits that are dissimilar from species-
typical adaptive design; keeps traits stable for generations
✔✔Sexual Selection - ✔✔type of natural selection that selects for behaviours and traits
that increase the likelihood of reproducing
✔✔Modes of Sexual Selection - ✔✔1. Female Choice
2. Success in Combat
✔✔Sexually Selected Traits - ✔✔differs between the sexes and specific to breeding
season
✔✔Female Choice - ✔✔picking males with greatest resistance to locally prevalent
diseases
ex. in humans: deep voice, facial structure
✔✔Social Behaviours - ✔✔1. Cooperation
2. Selfishness
3. Altruism
4. Spite
✔✔Cooperation - ✔✔sometimes reaps more benefit to you than selfishness; cost to you
< benefit of your action
ex. geese foraging in groups
✔✔Altruism - ✔✔helping others survive and reproduce at a cost to yourself
✔✔Eusocial Hymenoptera - ✔✔includes all ants, some bees, and some wasps; most
individuals spend their lives serving the colony without reproducing
✔✔Direct Fitness - ✔✔fitness from personal reproduction
✔✔Indirect Fitness - ✔✔fitness from the reproduction of close genetic relatives
✔✔Inclusive Fitness - ✔✔direct fitness + indirect fitness
✔✔Hamilton's Rule - ✔✔rB>C; B is the benefit (in number of offspring equivalents)
gained by the recipient of the altruism, C is the cost (in number of offspring equivalents)
suffered by the donor while undertaking the altruistic behaviour, and r is the genetic
relatedness of the altruist to the beneficiary
