Biology section 6 key words Inheritance variation and evolution Flashcards
Allele
A version of a gene
Amino Acid
Small molecules from which proteins are assembled
Archaea
Primitive bacteria existing in extreme environments
Binomial system
The universal system of naming organisms using their genus and species
Asexual reproduction
A form of reproduction involving a single parent . creates genetically identical offspring.
Charles Darwin
The scientists who developed the theory of evolution by natural selection
Chromosomes
A long coiled molecule of DNA that carries genetic information in the form of genes
Classification
The organisation off organisms into grouped based on their characteristics and structure
dna
A double stranded polymer wound to form a double helix. carries the genetic code
Cystic fibrosis
A cellular membrane disorder resulting from the presence of a recessive allele
Dominant
Describes an allele that is always express. represented by a capital letter
Embryo screening
A procedure used to determine the presence of faultily genes in an embryos produces through ivf. a few embryonic cells are removed and screened for defective alleles
Evolution
The gradual change in inherited traits within a population over time. occurs due to natural selection
Evolutionary tree
A diagram which illustrates the evolutionary relationships between organisms
extinction
The death of all members of a species
Family tree
A chart used to show the inheritance of a condition in a family
fossil
The remains of dead organisms found in rocks which are millions of years old
Fertilisation
The fusion of the nucleus of males and female gametes. restores the full chromosome number.
gametes
Sex cells(sperm egg pollen) with half the usual number of chromosomes
gene
A section of DNA that codes for a specific sequence of amino acids which undergo polymerisation to form protein
Genetic engineering
The modification of the genome of an organism by the insertion of a desired gene from another organisms enabling the formation of organisms with beneficial characteristics
genome
The complete genetic material of an organism
genotype
An organisms genetic composition describes all alleles
gm crops
crops that have had their genomes modified by the insertion of a desired gene from another organism
Inbreeding
The formation of offspring from the breeding of closely related individuals
Heterogynous
gene when someone has two different alleles e.g Ff
Linnaean system
The classification of organisms into kingdom phylum class order family genus and species as developed by Carl Linnaean
Homozygous
When someone has two identical alleles of a gene e.g. FF
meiosis
A form of cell division that produces gametes non identical calls with half the usual number of chromosomes
mitosis
A form of cell division that produces two genetically identical daughter cells ( with a full set of chromosomes ) from one parent cell
mrsa
A type of bacteria that is resistant to the antibiotic, methicillin
mutation
A random change in DNA which may result in genetic variation
natural selection
The process by which the frequency of advantageous traits passed on in gene gradually increases in a population over time
phenotype
An organism’s observable characteristics due to interactions of the genotype and the environment
polydactyly
A condition where an individual is born with extra fingers or toes due to the presence of a dominant allele
Punnett square
A grind used to predict the potential outcomes of a genetic cross
recessive
Describes an allele that is only expressed in the absence of a dominant allele represented by a small letter
ribosomes
Sub-cellular structure where protein synthesis takes place
sex chromosomes
A pair of chromosomes responsible for the determination of gender xy in male and xx in females
selective breeding
The process by which humans artificially select organisms with desirable characteristics and bred them to produce off spring with desirable phenotypes
Sexual reproduction
A form of reproduction involving the fusion of male and female gametes creating genetic variation
Species
A group of similar organisms that are able to bread with one another to produce fertile offspring
Three domain system
A method of classification in which organisms are categorised into three groups: archaea bacteria an eukaryote which was developed by carl woese
Variation
The differences between individuals due to genes, the environment or a combination of both
Vector
A carrier used to transfer a gene from one organism to another
