Studied by 20 people
Asexual reproduction
produces new individuals that are identical to their parents; does not involve the fusion of gametes
Gamete
a specialised sex cell formed by meiosis
Runners
long shoots from plants, such as strawberries, that are used for asexual reproduction
Meiosis
cell division that forms daughter cells with half the number of chromosomes of the parent cell
DNA
nucleic acid molecules that contain genetic information and make up chromosomes
Chromosomes
long molecules found in the nucleus of all cells; made from DNA
Gene
part of a chromosome, made of DNA, which codes for a protein
Genome
all the genetic material found in an organism or a species
Polymer
a large molecule that is made up of many repeating units
Nucleotide
a molecule made of a phosphate group, a sugar and an organic base
Collagen
a protein found in connective tissue under the skin and in tendons
Mutation
a spontaneous change in the genetic material of a cell
Allele
an alternative form of a particular gene
Genotype
the combination of alleles an individual has for a particular gene, e.g. BB, Bb or bb
Phenotype
the physical expression of the genotype, i.e. the characteristic shown
Dominant
an allele that only needs to be present once in order to be expressed; represented by a capital letter
Recessive
an allele that will only be expressed if there are two present; represented by a lower case letter
Homzygous
when an individual carries two copies of the same allele for a gene, e.g. BB or bb
Heterozygous
when an individual carries two different alleles for a gene, e.g. Bb
Monohybrid inheritance
the pattern of inheritance shown when a characteristic is controlled by a single gene
Punnett square
a type of diagram used to work out the outcome of genetic crosses
Polydactyly
a genetic disorder caused by a dominant allele, where affected people have extra fingers or toes
Cystic fibrosis
a genetic condition that causes a build-up of mucus in the lungs
Sex chromosomes
the pair of chromosomes that determine the sex of organism
Variation
differences between individuals of the same species
Evolution
a gradual change in a group of organisms over a long period of time
Natural selection
the survival of individual organisms that are best adapted to their environment
Fossils
the remains of animals / plants preserved in rock
Selective breeding
the breeding process used by scientists and farmers to produce organisms that show the characteristics that are considered useful
Genetic engineering
the process of moving a gene from one organism to another
Genetically modified (GM)
organisms that have had specific areas of their genetic material changed using genetic engineering techniques
Clone
an offspring that is genetically identical to the parent organism
Cuttings
a method of asexually reproducing plants, used by gardeners, by planting small lengths of plant shoots
Tissue culture
a method of producing large numbers of plants asexually by growing small parts of plants in a nutrient jelly
Surrogate
a female that gestates and gives birth to an organism that has not been produced from one of her own egg cells
Binomial system
the method of naming organisms by using their genus and species
Genus
a group of closely related species
Species
a group of organisms that can reproduce with each other to produce fertile offspring
Three-domain system
a new classification system that divides organisms into three domains rather than five kingdoms
Extinct
describes a species that has died out
Speciation
where populations have become so different that successful interbreeding is no longer possible
Note
Flashcard