Changes in genetic makeup Flashcards
An allele is ?
a variation of a gene at a particular gene locus
A species is defined as …
A group of organisms that interbreed to produce viable and fertile offspring
Phenotype is the ?
physical, behavioural or physiological characteristic of an organism which are a result of the combination of genotype and the environment
Allele frequency is ..
The proportion of one allele in a population
A point mutation is when ?
one single nucleotide is changed
A silent mutation is where the ?
Base changes but still codes for the same base as the DNA code is degenerate
A missense mutation is where ?
Base changes and so does the amino acids coded for so may affect the function of the protein
A nonsense mutation is where ?
Base changes and so does the amino acids coded creating a stop codon and a non-functional protein
A population is defined as ?
a group of individuals of the same species in the same defined geographical area
Evolution is the ?
change in allele frequency over time
Gene flow is ?
The movement of individual in and out of of a population changing allele frequency
Allopatric speciation is ?
Speciation due to geographical barriers separating a population
Genetic drift is the ?
change in allele frequencies in a population by chance
Founder effect is when ?
A group of individuals, whose allele frequency unrepresentative of the normal population, breakawayand found a new population
Bottleneck effect is ?
A severe reduction in genetic diversity due to a catastrophe that may change allele frequency
Extinction is defined as ?
When no member of a particular species exists
Selective breeding is ?
Humans choosing which organisms will breed, and pass on their alleles, based on desired traits
Define biological fitness
The ability to survive, reproduce and pass on alleles to the next generation
Define selective agent/pressure
A factor in an organism’s environment that removes unsuited individuals from a population
Using the acronym list the 5 steps of Natural Selection
VA – There is variation in the phenotypes in the xxxxxxx population due to random mutations as they have xxxxxxx
ST – All organisms face a daily struggle to survive and reproduce. Thexxxxxx withxxxxxx struggle because xxxxx (selection pressure)
SE – The xxxxx with xxxhave a selective advantage as they xxxxx
IN – The organisms that have a selective advantage (xxxx), survive, reproduce and their offspring inherit the alleles for the trait of XXXXXX
E – Evolution occurs by natural selection and there is a change in allele frequency over time and theXXX population becomes better suited to its environment.
Define gene pool
The complete set of alleles present in a population.
Aneuploidy is ?
A diploid cell with too many or too few chromosomes compared to their normal diploid number.
Polyploidy is ….
A cell with more than one paired set of chromosome
The structure for an allopatric speciation question must include
Geographical barrier - no gene flow
Populations have different selection pressures and so allele frequencies change
Overtime the two populations are so different they cannot interbreed to produce viable fertile offspring
