chap 9- glossary

Question 1

amino acid sequence

Answer 1

Amino Acid Sequence- the primary structure of a protein; comprises the order of the 20 possible amino acids in the polypeptide, sometimes referred to as ‘polypeptide sequence’.

Question 2

antibiotic resistance

Answer 2

Antibiotic resistance- the capacity for a microbe to withstand the lethal effects of an antibiotic to which it was once susceptible.

Question 3

antibiotic resistance gene

Answer 3

Antibiotic resistance gene- a gene that codes for an antibiotic resistant phenotype.

Question 4

antigenic drift

Answer 4

Antigenic drift- a change in the antigen of a virus that would otherwise be recognisable by the adaptive immune system, resulting from the gradual accumulation of mutations in the virus.

Question 5

antigenic shift

Answer 5

Antigenic shift- a sudden change in the antigen of a virus resulting from the rearrangement of genetic material from two or more strains or subtypes of the virus.

Question 6

artificial selection

Answer 6

Artificial selection- breeding of plants and animals over successive generations to produce traits hat are desirable to humans; also known as ‘selective breeding’.

Question 7

beneficial mutation

Answer 7

Beneficial mutation- a mutation that increases the organisms chances of survival and reproduction.

Question 8

block mutation

Answer 8

Block mutation- a mutation involving rearrangements of chromosomal segments.

Question 9

bottleneck effect

Answer 9

Bottleneck effect- when a catastrophic event or a period of adverse conditions drastically reduces the size of a population and its genetic diversity.

Question 10

broad spectrum

Answer 10

Broad spectrum- describes an antibiotic (or insecticide) that is effective against a variety of organisms.

Question 11

conserved

Answer 11

Conserved- amino acids of polypeptide sequences or nucleotides of DNA sequences that remain consistent across species.

Question 12

deleterious mutation

Answer 12

Deleterious mutation- a mutation that decreases the organisms chances of survival and reproduction.

Question 13

deletion mutation

Answer 13

Deletion mutation- a mutation in which nucleotide pairs have been lost from a segment of DNA.

Question 14

double-strand break

Answer 14

Double-strand break- a mutation involving breaks in the sugar-phosphate backbones at the same nucleotide pair, resulting in the complete breakage of a chromosome.

Question 15

duplication

Answer 15

Duplication- a mutation that occurs when one or more extra copies are made of a section of chromosome.

Question 16

extinct

Answer 16

Extinct- when al the members of a population or species have died out.

Question 17

fitness

Answer 17

Fitness- the capacity of an individual to survive and produce viable offspring.

Question 18

fixed

Answer 18

Fixed- describes an allele when it is the only variant available for a particular gene in the gene pool of a population.

Question 19

founder effect

Answer 19

Founder effect- the type of gene flow that occurs when a few individuals that have become isolated from a larger population do not carry all the alleles that were present in the original population.

Question 20

gene duplication

Answer 20

Gene duplication- generating an extra copy of a gene within a genome as a result of duplication of a chromosomal segment.

Question 21

gene flow

Answer 21

Gene flow- the transfer of alleles that results from emigration and immigration of individuals between populations.

Question 22

gene pool

Answer 22

Gene pool- the range of genes and all their alleles present in a population.

Question 23

gene sequence

Answer 23

Gene sequence- the sequence of nucleotides in a gene.

Question 24

genetic drift

Answer 24

Genetic drift- the change in the gene pool of a population as a result of chance, usually occurs in small populations.

Question 25

genotype

Answer 25

Genotype- a specific combination of alleles for a particular gene locus belonging to an individual.

Question 26

germline

Answer 26

Germline- a cell line in eukaryotic organisms from which the gametes are derived.

Question 27

heritable

Answer 27

Heritable- capable of being passed on to the next generation.

Question 28

horizontal gene transfer

Answer 28

Horizontal gene transfer- the process by which genetic material from one organism becomes incorporated into the genome of another organism.

Question 29

insertion mutation

Answer 29

Insertion mutation- a mutation in which nucleotide pairs have been added to a segment of DNA.

Question 30

inversion mutation

Answer 30

Inversion mutation- a mutation resulting in the normal sequence of genes being reversed in a chromosome.

Question 31

missense mutation

Answer 31

Missense mutation- a mutation that results in one amino acid being replaced by another amino acid in the encoded protein.

Question 32

monoculture

Answer 32

Monoculture- the practice of cultivating a single genetically uniform breed of plant or livestock.

Question 33

multidrug resistance

Answer 33

Multidrug resistance- when a bacterium becomes resistant to two or more antibiotics.

Question 34

mutagen

Answer 34

Mutagen- an agent capable of inducing mutations.

Question 35

mutation

Answer 35

Mutation- when a gene or chromosome has undergone a change relative to the original gene or chromosome; it may also refer to he process of generating such changes.

Question 36

natural selection

Answer 36

Natural selection- the process whereby individuals with certain heritable traits survive and reproduce more successfully than other individuals.

Question 37

neutral mutation

Answer 37

Neutral mutation- a mutation that has no effect on the organisms chances of survival and reproduction.

Question 38

nonsense mutation

Answer 38

Nonsense mutation- a mutation in which a codon for an amino acid is changed to one that codes for a stop codon, terminating translation.

Question 39

phenotype

Answer 39

Phenotype- the actual form taken by a specific feature in a particular individual based on their genotype; can be used in reference to particular traits or characteristics or to the overall form of an individual.

Question 40

point mutation

Answer 40

Point mutation- a mutation that affects a single base-pair position within a gene.

Question 41

population

Answer 41

Population- a group of individuals of the same species that live in the same area and interbreed, producing fertile offspring.

Question 42

population genetics

Answer 42

Population genetics- the study of allele frequencies in population and how they change over time.

Question 43

selection pressure

Answer 43

Selection pressure- a factor that favours the survival of some individuals over others within a population.

Question 44

silent mutation

Answer 44

Silent mutation- a mutation in which the DNA codon for one amino acid becomes another DNA codon for the same amino acid; also referred to as synonymous mutation.

Question 45

somatic

Answer 45

Somatic- describes a body cell that will not pass its genes on to the next generation.

Question 46

species

Answer 46

Species- a group of similar organisms capable of breeding and exchanging genes with one another and whose offspring are capable of doing he same; also describes the lowest formal taxonomic rank and forms the second part of an organisms scientific name.

Question 47

subspecies

Answer 47

Subspecies- the level of classification below species, referring to races of a species that are geographically isolated from each other.

Question 48

substitution mutation

Answer 48

Substitution mutation- a mutation in which a single nucleotide is swapped for another in the original gene sequence.

Question 49

translocation

Answer 49

Translocation- a mutation occurring when a section of one chromosome breaks off and reattaches to another chromosome.