Chapter 3

Question 1

Adaptation

Answer 1

An inherited characteristic that increased in a population (through natural selection) because it helped solve a problem of survival or reproduction during the time it emerged.

Question 2

Adoption studies

Answer 2

Research studies that assess hereditary influence by examining the resemblance between adopted children and both their biological and their adoptive parents.

Question 3

Agonist

Answer 3

A chemical that mimics the action of a neurotransmitter.

Question 4

Antagonist

Answer 4

A chemical that opposes the action of a neurotransmitter.

Question 5

Behavioural genetics

Answer 5

An interdisciplinary field that studies the influence of genetic factors on behavioural traits.

Question 6

Critical period

Answer 6

A limited time span in the development of an organism when it is optimal for certain capacities to emerge because the organism is especially responsive to certain experiences.

Question 7

Dominant gene

Answer 7

A gene that is expressed when paired genes are heterozygous (different).

Question 8

Electrical stimulation of the brain (ESB)

Answer 8

Sending a weak electric current into a brain structure to stimulate (activate) it.

Question 9

Endorphins

Answer 9

The entire family of internally produced chemicals that resemble opiates in structure and effects.

Question 10

Excitatory PSP

Answer 10

An electric potential that increases the likelihood that a postsynaptic neuron will fire action potentials.

Question 11

Family studies

Answer 11

Scientific studies in which researchers assess hereditary influence by examining blood relatives to see how much they resemble each other on a specific trait.

Question 12

Fitness

Answer 12

The reproductive success (number of descendants) of an individual organism relative to the average reproductive success of the population.

Question 13

Forebrain

Answer 13

The largest and most complicated region of the brain, encompassing a variety of structures, including the thalamus, hypothalamus, limbic system, and cerebrum.

Question 14

Genes

Answer 14

DNA segments that serve as the key functional units in hereditary transmission.

Question 15

Genetic mapping

Answer 15

The process of determining the location and chemical sequence of specific genes on specific chromosomes.

Question 16

Genotype

Answer 16

A person’s genetic makeup.

Question 17

Heterozygous condition

Answer 17

The situation that occurs when two genes in a specific pair are different.

Question 18

Hindbrain

Answer 18

The part of the brain that includes the cerebellum and two structures found in the lower part of the brainstem: the medulla and the pons.

Question 19

Homozygous condition

Answer 19

The situation that occurs when two genes in a specific pair are the same.

Question 20

Inclusive fitness

Answer 20

The sum of an individual’s own reproductive success plus the effects the organism has on the reproductive success of related others.`

Question 21

Inhibitory PSP

Answer 21

An electric potential that decreases the likelihood that a postsynaptic neuron will fire action potentials.

Question 22

Lesioning

Answer 22

Destroying a piece of the brain.

Question 23

Limbic system

Answer 23

A densely connected network of structures roughly located along the border between the cerebral cortex and deeper subcortical areas.

Question 24

Midbrain

Answer 24

The segment of the brain stem that lies between the hindbrain and the forebrain.

Question 25

Mutation

Answer 25

A spontaneous, heritable change in a piece of DNA that occurs in the individual organism.

Question 26

Natural selection

Answer 26

Principle stating that heritable characteristics that provide a survival reproductive advantage are more likely than alternative characteristics to be passed on to subsequent generations and thus come to be “selected” over time.

Question 27

Perceptual asymmetries

Answer 27

Left–right imbalances between the cerebral hemispheres in the speed of visual or auditory processing.

Question 28

Phenotype

Answer 28

The ways in which a person’s genotype is manifested in observable characteristics.

Question 29

Polygenic traits

Answer 29

Characteristics that are influenced by more than one pair of genes.`

Question 30

Postsynaptic potential (PSP)

Answer 30

A voltage change at the receptor site on a postsynaptic cell membrane.

Question 31

Recessive gene `

Answer 31

A gene whose influence is masked when paired genes are different (heterozygous).`

Question 32

Split-brain surgery

Answer 32

A procedure in which the bundle of fibres that connects the cerebral hemispheres (the corpus callosum) is cut to reduce the severity of epileptic seizures.

Question 33

Twin studies

Answer 33

A research design in which hereditary influence is assessed by comparing the resemblance of identical twins and fraternal twins with respect to a trait.