Chapter 9 - How species evolve

Question 1

adaptive potential

Answer 1

the ability for a population to adjust to new environmental selection pressures

Question 2

advantageous phenotype

Answer 2

a biochemical, physical, or behavioural trait that increases an organism’s fitness in its local environment

Question 3

allele

Answer 3

an alternate form of a gene

Question 4

allele frequency 

Answer 4

the proportion of certain alleles in a gene pool

Question 5

allopatric speciation

Answer 5

the geographic separation of a population from a parent population resulting in the formation of a new species

Question 6

aneuploidy

Answer 6

when a cell or organism varies in the usual amount of chromosomes in its genome by the addition or loss of a chromosome

Question 7

antigenic drift

Answer 7

small and gradual mutations in the genes encoding for viral surface antigens

Question 8

antigenic shift 

Answer 8

sudden and significant mutations in the genes encoding for viral surface antigens

Question 9

antimicrobial agent

Answer 9

an agent that kills or slows the growth of microorganisms. Examples include antiseptics, disinfectants, antifungals, antivirals, and antibacterial agents

Question 10

antimicrobial resistance

Answer 10

the ability of a microorganism to survive exposure to an antimicrobial agent

Question 11

bacterial conjugation

Answer 11

the process in which bacteria exchange genetic material via direct cell-cell contact

Question 12

block mutation

Answer 12

a mutation that affects a large chunk of DNA, or an entire gene

Question 13

bottleneck effect

Answer 13

the reduction in genetic diversity that occurs when a large proportion of a population is removed due to a chance event

Question 14

competition

Answer 14

interactions between organisms in which both are negatively impacted when vying for the same limited resource. Can exist within or between species

Question 15

degenerate

Answer 15

a property of the genetic code which means that a single amino acid can be coded for by more than one codon

Question 16

deleterious

Answer 16

used to describe alleles that have an overall negative effect on individual fitness when expressed

Question 17

deleterious allele

Answer 17

an allele that has an overall negative effect on individual fitness when expressed

Question 18

desirable trait

Answer 18

a heritable phenotype that humans select for during selective breeding

Question 19

disadvantageous allele

Answer 19

an allele that encodes for a biochemical, physical, or behavioural trait that lowers an individual’s fitness in its local environment

Question 20

ecological niche 

Answer 20

the specific environmental conditions and resources or selection pressures within a particular environment

Question 21

emigration

Answer 21

the movement out of a population

Question 22

environmental selection
pressure

Answer 22

a factor in the environment (e.g. limited resources, deforestation, changing temperature, predation) that impacts an organism’s ability to survive and reproduce

Question 23

epidemic 

Answer 23

a dramatically increased occurrence of a disease in a particular community at a particular time

Question 24

evolution

Answer 24

the change in the genetic makeup of a population over successive generations

Question 25

fertile

Answer 25

the ability to produce offspring

Question 26

fitness 

Answer 26

a measure of how well an organism survives and reproduces in its environment

Question 27

founder effect

Answer 27

the reduction in genetic diversity that occurs when a population is derived from a small unrepresentative sample of the original population

Question 28

frameshift mutation 

Answer 28

a mutation that involves the insertion or deletion of one or two nucleotides, altering every codon from that point forward

Question 29

gene flow

Answer 29

the flow of alleles in and out of a population due to the migration or interbreeding of individuals between two populations

Question 30

gene pool 

Answer 30

the complete set of alleles present within a particular population

Question 31

genetic diversity

Answer 31

the variation in genetic makeup or alleles within a population

Question 32

genetic diversity

Answer 32

the variation in genetic makeup or alleles within a population

Question 33

genetic diversity 

Answer 33

the variation in genetic makeup or alleles within a population

Question 34

genetic drift 

Answer 34

a random event that dramatically alters a population’s gene pool

Question 35

gene 

Answer 35

a section of DNA that carries the code to make a protein

Question 36

genotype

Answer 36

the genetic composition of an organism at a particular gene locus

Question 37

geographic barrier

Answer 37

a physical factor that prevents gene flow, and thereby stops two populations from breeding together

Question 38

germline cell 

Answer 38

a cell involved in the generation of gametes in eukaryotes

Question 39

heritability

Answer 39

the transmission from parent to offspring (i.e. encoded in genes)

Question 40

homozygous 

Answer 40

having identical alleles for the same gene on homologous chromosomes

Question 41

immigration

Answer 41

the movement into a population

Question 42

inbreeding 

Answer 42

sexual reproduction between two related individuals

Question 43

interbreeding 

Answer 43

when two individuals living in different populations mate and have offspring

Question 44

missense mutation 

Answer 44

a mutation in which a nucleotide is substituted for another, changing the codon and coding for a different amino acid. Therefore, there can potentially be an effect on protein structure

Question 45

mutagen

Answer 45

an agent that can cause mutations in DNA

Question 46

mutation

Answer 46

a permanent change to a DNA sequence

Question 47

natural selection

Answer 47

a mechanism through which organisms that are better adapted to their environment have an increased chance of surviving and passing on their alleles

Question 48

nonsense mutation

Answer 48

a mutation in which a nucleotide is substituted for another, changing the codon to a stop codon, prematurely ceasing translation of the gene’s mRNA. Therefore, there is an effect on protein structure

Question 49

normal flora 

Answer 49

naturally occurring, non-pathogenic microbes present in an organism

Question 50

pandemic

Answer 50

an epidemic that has spread across multiple countries and/or continents

Question 51

phenotype

Answer 51

the physical or biochemical characteristics of an organism that are the result of gene expression and the environment

Question 52

point mutation 

Answer 52

a mutation that alters a single nucleotide in a DNA sequence

Question 53

polyploidy 

Answer 53

when an organism contains additional sets of chromosomes in its genome

Question 54

population

Answer 54

a group of organisms of the same species living in the same area

Question 55

reading frame

Answer 55

the order in which nucleotide triplets or codons are divided into a consecutive, non-overlapping sequence

Question 56

recessive allele

Answer 56

a trait that can be masked by a dominant allele on a homologous chromosome

Question 57

selective advantage

Answer 57

an organism conferred a beneficial allele, which increases its chances of survival against a specific environmental selection pressure

Question 58

selective breeding

Answer 58

the changing of a population’s gene pool due to humans altering the breeding behaviour of animals and plants to develop a selected trait. Also known as artificial selection

Question 59

silent mutation

Answer 59

a mutation in which a nucleotide is substituted for another, changing the codon, but still coding for the same amino acid. Therefore, there is no effect on protein structure

Question 60

somatic cell

Answer 60

any cell in an organism that is not a germline cell

Question 61

species

Answer 61

a group of individuals who are able to breed with each other and produce viable and fertile offspring

Question 62

sympatric speciation 

Answer 62

the divergence of a species from an original species without the presence of a geographical barrier

Question 63

unrepresentative sample

Answer 63

a small selection of individuals from a larger group that does not reflect the characteristics of the larger group

Question 64

viable

Answer 64

able to survive

Question 65

viral recombination

Answer 65

the combination of surface antigens from two or more different strains of a virus to form a completely new virus subtype

Question 66

virulence

Answer 66

the potential of a pathogen or disease to cause serious illness or harm