Chapter 4: Genes, Evolution and Behaviour

Question 1

genotype

Answer 1

the specific genetic makeup of an individual

Question 2

phenotype

Answer 2

the observable characteristics produced by that genetic endowment

Question 3

chromosome

Answer 3

a structure of DNA in the nucleus that is formed when DNA is wrapped tightly around proteins

Question 4

zygote

Answer 4

a cell containing 23 chromosomes from egg and 23 from sperm

Question 5

gene

Answer 5

a segment of the DNA that codes for a protein that is used to express that trait on the organism

Question 6

allele

Answer 6

two genes that are located on homologous chromosomes that code for a similar polypeptide that helps express that same type of trait

Question 7

dominant

Answer 7

the particular characteristic that it controls will be displayed

Question 8

recessive

Answer 8

characteristic that will not show up unless the partner gene inherited from the other parent is also recessive

Question 9

epigenetics

Answer 9

refers to lasting changes in gene expression during development that were not due to genetic changes

Question 10

recombinant DNA procedures

Answer 10

researches use specific enzymes to cut the long threadlike molecules of genetic DNA into pieces, combine them with DNA from another organism, and insert the new strands into a host organism, such as bacterium

Question 11

knockout procedure

Answer 11

procedure done with animals that alters a specific gene in a way that prevents it from carrying out its normal function

Question 12

heredity

Answer 12

the passage of characteristics from parents to offspring by way of genes

Question 13

heritability

Answer 13

means how much of the variation in a characteristic within a population can be attributed to genetic differences

• applies to differences within a group, not to differences between groups

Question 14

adoption study

Answer 14

research method in which a person who was adopted easily in life is compared on some characteristics both with the biological parents and adoptive parents

Question 15

twin studies

Answer 15

one of the more powerful techniques used in behaviour genetics

• In conclusion, genetics and environmental factors almost always interact with each other to influence behaviour

Question 16

reaction range

Answer 16

the range of possibilities that the genetic code allows

Question 17

evolution

Answer 17

the change overtime in the frequency with which particular genes - and the characteristics they produce - occur within an interbreeding population

Question 18

mutation

Answer 18

random events and accidents in gene reproduction during cell division

• mutations that occur in the cells that become sperm and egg cells will alter the genes, and those genes will be passed onto offspring
• help to create variation within a population’s physical characteristics which makes evolution possible

Question 19

natural selection

Answer 19

• characteristics that increase the likelihood of survival and the ability to reproduce within a particular environment will be more likely to be preserved in the population and therefore will become more common in the species overtime

Question 20

adaptations

Answer 20

allows organisms to meet recurring environmental challenges to their survival, thereby increasing their reproductive ability

Question 21

parental investment

Answer 21

refers to the time, effort, energy and risk associated with caring successfully for each offspring

Question 22

monogamous mating system

Answer 22

if both male and female investment is high

Question 23

polyandry

Answer 23

one female mates with many males

Question 24

molygynandry

Answer 24

in which all members of the group mate with all members of the group

• for highly social species, this is one possible way to reduce competition for a mate

Question 25

cooperation

Answer 25

refers to situations in which one individual helps another and in so doing also gains some advantage

Question 26

altruism

Answer 26

occurs when one individual helps another, but in doing so he or she accrues some cost

• There are two important theories of altruism:
  1. kinselection theory - argues that altruism developed to increase the survival of relations
  2. theory of reciprocal altruism - theory that argues altruism is long-term cooperation - that is, one individual may help another but that assistance will be reciprocated sometime in the future