Higher Biology

Unit 2Genetics and

Adaptation

Glossary

NAME:

Artificial Selection – Glossary

Process by which only the organisms with the best features are chosen as the parents of the next generation.Plant cell consisting of cell membrane, cytoplasm and nucleus but lacking a cell wall.Process by which protoplasts from two species form a hybrid containing a mixture of genetic traits.Enzyme used to seal a new gene into a bacterial plasmidProcess by which one variety of organism is crossed with a different variety to try to produce offspring better than either parent.Short length of single-stranded DNA capable of binding to single stranded DNA of required geneEnzyme used to cut DNA into fragments and open up bacterial plasmidsCondition shown by offspring from cross between two different inbred parental strainsEnzyme which digests cellulose in plant cell wallsProcess by which genetic material from one organism is inserted into the genome of another.Single haploid set of chromosomes typical of a speciesProcess by which close relatives are bred with one another and prevented from mating at random.

cellulaseendonucleasegene probegenetic engineeringgenomehybrid vigour

hybridisationinbreeding

ligaseprotoplastselective breedingsomatic infusion

Natural Selection – Glossary

Process by which individuals best adapted to the environment survive and pass their genes on to succeeding generations.Characteristic shown by some mutant plants enabling them to thrive in soil polluted with copper or lead.Benefit gained by mutant organisms in an environment which suits them but not other members of the populationVersion of a gene containing genetic material different from the originalCondition where the person’s blood contains some haemoglobin S making them resistant to malariaType of micro-organism whose growth is not inhibited by chemicals such as penicillinMember of a pair of plant ecotypes that grows best on acidic soilsMember of a pair of plant ecotypes that grows best on calcium-rich soilsChemical made by one micro-organism that inhibits the growth of some other micro-organismsForm a contact between two bacteria which allows the transfer of genetic material from one to another.

Antibioticantibiotic resistantcalcicolecalcifugeconjugation

heavy metal tolerancemutant allelenatural selection

selective advantagesickle cell trait

Speciation – Glossary

Total of all the different alleles present in the genotypes of the members of a population

barrier which prevents gene exchange between sub=populations of a species

formation of new species

process by which the frequency of an allele increases if its phenotypic expression gives the organism an advantagegroup of organisms that produce fertile offspring and share the same basic anatomy and physiologyfrequency with which an allele occurs in agene pool compared to the other alleles at the same locusterm used to describe organisms which only occur in a particular region such as an island

introduction to a gene pool of new alleles from a different gene pool

process by which the world's land masses have gradually moved apart

variation in gene frequency within a splinter group that is atypical of the main population

Endemiccontinental driftgene frequencygene migrationgene poolgenetic driftisolating mechanismnatural selectionspeciation

species

Meiosis– Glossary

one of the two longitudinal sub-units of a duplicated chromosomepossessing two sets of chromosomes the characteristic number of chromosomes typical of a speciescross-shaped arrangement of two chromatids at a point of crossing oversmall region of chromosome which becomes associated with spindle fibres during meiosisunit of heredity occupying a specific site on a chromosomea form of nuclear division producing four haploid gametes from a diploid celltwo chromosomes identical in size and matching one another gene for gene (although alleles may differ)differences that exist amongst the members of a species that are determined by genesbreaking and rejoining of adjacent chromatids leading to exchange of genetic materialthread-like structure composed of genes and found in the nucleus of a cellarrangement of homologous pairs of chromosomes that allows their segregation at meiosis

possessing one set of chromosomes

centrometre genechiasma haploidchromatid homologous pairchromosome independent assessmentchromosome complement inherited variationcrossing over meiosisdiploid

Monohybrid cross – Glossary

genotype possessing two different alleles of a gene

form of gene that is masked by the presence of the dominant form

breeding experiment involving two true-breeding parents differing in only one way

condition of heterozygote in which one allele is fully expressed in the phenotype and the other is masked

the complete set of genes possessed by an organism

condition of heterozygote in which partial expression of alleles produces a phenotype intermediate between the two homozygotes

genotype possessing two identical alleles of a gene

an organism's appearance resulting from genetic information inherited from parents

complete dominancegenotypeheterozygoushomozygous

incomplete dominancemonohybrid crossphenotyperecessive allele

Sex Linkage – Glossary

inheritance pattern of alleles of genes carried on one sex chromosome but not on the other

sex-linked condition where blood fails to clot properly

smaller of the two human sex chromosomes

larger of the two human sex chromosomes

gene present on X chromosome but not on Y chromosome

female who is heterozygous for a sex-linked gene

able to form one type of sex cell only

able to form two types of sex cell

type of chromosome not involved in sex determination

relative number of males to females in a population

autosomecarrierhaemophiliaheterogametichomogametic

sex linkagesex-linked genesex ratioX chromosomeY chromosome

Mutation – Glossary

doubling up of a part of a chromosome involving several genes

loss of a segment of chromosome consisting of several genes

condition characterized by the chromosome complement 2n = 44 + XOform of mutation involving one or more extra sets of chromosomes being added to a species' chromosome complementtransfer of a segment of genes from one chromosome to another non-homologous oneincrease in chromosome number of a cell caused by spindle failure during meiosis or mitosisreversal of the gene order of a segment of chromosome as a result of two breaks in the same chromosome condition resulting from non-disjunction of chromosome 21 during meiosis

condition characterized by the chromosome complement 2n = 44 + XXY

display of matched chromosomes showing their number, form and size

.

deletionDown's syndromeduplicationinversionkaryotype

Klinefelter's syndromenon-disjunctionpolyploidytranslocationTurner's syndrome

Adaptive radiation – Glossary

term describing the evolution of structures that differ in function but share a common ancestor

body parts of different species that share the same evolutionary origin but may differ in function

inherited characteristic that makes an organism well suited to its environment

mammal whose young are born after a relatively long gestation period in the mother's uterus

mammal whose young are born after a relatively short gestation period and reared in a pouch

term describing the evolution of structures that perform the same function but do not share a close common ancestor

process by which organisms evolve along separate lines involving adaptation to different environments

role played by a species within a community

adaptive radiationconvergentdivergentecological niche

homologousmarsupialplacentalstructural adaptation

Extinction and conservation – Glossary

heritable variation that exists amongst living things

irreversible loss of a species of living thing from planet Earth

types of living organism that thrive in habitats degraded by human activities

centre specializing in unusual or otherwise extinct relatives of farm animals

region of the world possessing wild relatives of modern crop plants

protection and careful management of a natural resource

human activity leading to possible extinction of many species

long-term storage site of seeds and sex cells of rare and valuable species

cell bankcentre of diversityconservationextinction

genetic diversityhabitat destructionopportunist speciesrare-breed farm

Maintaining a water balance-animals – Glossary

lower in water concentration compared with another solution

control of water balance by a living organism

process by which water passes from a hypotonic to a hypertonic solutioninherited characteristic which suits an organism to its environment and increases its chance of survival

equal in water concentration to another solution

nitrogenous waste made by freshwater fish

nitrogenous waste made by saltwater fish

nitrogenous waste made by mammals

site of active transport of salt ions into a freshwater fish and out of a saltwater fish

site of filtration of blood in a kidney

higher in water concentration compared with another solutionbehavioural adaptation which enables an animal to spend part of its life in one environment and part in another

adaptation migrationammonia osmoregulationchloride secretory cell osmosisglomerulus trimethylamine oxidehypertonic ureahypotonic isotonic

Maintaining a water balance-plants – Glossary

the continuous passage of water through a plant from its roots to its leavesinstrument used to measure the rate of water uptake by a plantforce caused by the flow of water into a plant from the soil solution by osmosismajor force responsible for the ascent of water in the transpiration stream

pore in a leaf surface controlled by guard cells

force of attraction between particles which makes water rise up narrow tubesloss of water by evaporation from the aerial parts of a plantplant adapted to life completely or partially submerged in waterplant adapted' to a habitat where soil water is lacking or conditions are excessively windy'normal' plant adapted to a habitat where soil water is plentifulinstrument used to measure the rate of evaporation of water from a non living surface

control of water balance by a living organism

atmometer transpirationcapillarity transpiration pullhydrophyte transpiration steammesophyte xerophyteosmoregulation root pressurepotometer stoma

Obtaining food-animals – Glossary

social signal used by a low-ranking member of a social hierarchy to indicate acceptance of the dominant leaderstruggle for existence between members of different species when a resource is scarcearea inhabited and defended by an individual animal or a breeding pair

time spent by a foraging animal to locate food

result of interspecific competition where one species ousts another from an ecosystemsystem of social organization where the members are graded into a rank ordersocial signal used by the leader in a dominant hierarchy to assert authoritycompetition amongst members of the same species for territoriestype of foraging behaviour employed by a group of predators resulting in mutual benefits

time spent by a foraging animal to obtain food

struggle for existence between members of the same species when a resource is scarceoverall profit made by an animal when foraging costs are subtracted from benefits

competitive exclusion ritualised threat gestureco-operative hunting search timedominance hierarchy subordinate responseinterspecific competition territorialityintraspecific competiton territorynet energy gain pursuit time

Obtaining food-plants – Glossary

arrangement of leaves which results in minimal overlap and maximum absorption of light

autotrophy that thrives in brightly illuminated habitats

ability of a living organism to move its whole body from place to place

the light intensity at which a plant's rate of photosynthesis equals its rate of respiration

autotrophy that thrives in dimly lit habitats

mode of life where an organism remains fixed to one position in its habitat

term describing an organism that requires a ready-made source of food

struggle for existence between members of the same species when a resource is scarce

term describing an organism able to make its own food by photosynthesis

struggle for existence between members of different species when a resource is scarce

autotrophiccompensation pointheterotrophicinterspecific competitionintraspecific competitionmobilitymosaic patternsessilityshade plant

sun plant

Coping with dangers – Glossary

process by which an animal learns not to respond to a harmless stimulussocial defence mechanism enabling musk oxen to fend off carnivorous predatorsmeans by which an animal attempts to be ignored by a predator which only eats freshly killed preygeneral term for behaviour involving modification of the response made to a stimulusstructural adaptations possessed by some insects which can be used to startle a predatorauditory warning signal used as a social defence mechanism by many birds and mammalsuse of bogus eye spots to deceive predators about the true identity of a prey's head and tail endsmeans by which parent bird diverts a predator's attention from the young in a nest on the groundgeneral term for the means by which an animal copes with danger as a member of a co-operative groupgeneral term for a response made by an animal in order to escape potential dangerpassive defence mechanism which enables an animal to blend effectively with its backgroundgeneral term for the means by which a solitary animal copes with danger

alarm callavoidance behaviourcamouflagedeflection displaydistraction displayfeigning death

habituationindividual defence mechanismlearningmobbingsocial defence mechanismwing markings

Dihybrid Cross and Linkage -Glossary

Name given to the position of a gene on a chromosome

Segregation of different alleles of two genes on different chromosomes during gamete formation

Point of crossing over between adjacent chromatids during meiosis

Process by which new combinations of parental characteristics occur in a future generation

Breeding experiment involving heterozygous F1 organisms and individuals with the double recessive genotype

Form of a species that occurs most commonly in an ecosystem

General term for a breeding experiment involving two true-breeding parents differing in two different respects

Breaking and rejoining of adjacent chromatids leading to exchange of genetic material

Units of heredity located on the same chromosome

chiasmacrossing overdihybrid backcrossdihybrid cross

independent assortmentlinked geneslocusrecombinationwild type