meaning of “diploid”
two copies of each gene/chromosome, one from maternal and one from paternal
meaning of “haploid”
one copy of each gene/chromosome such as sperm/egg/gamete
meaning of “gene”
a fragment of DNA encoding RNA
meaning of “Alleles”
> alternative forms of same gene
> pair of genes on a chromosome that determines characteristics such as hair colour
meaning of “homologous”
same gene in different species
meaning of “homologues”
copies related by descent
meaning of “homolog”
anything the same, same function
meaning of “orthologs”
type of homolog that are a result of speciation
meaning of “paralogs”
type of homolog that is a result of duplication
meaning of “analogous”
similar function but having a different evolutionary origin, such as the wings of insects and birds.
meaning of “genotype”
specific allele composition
meaning of “phenotype”
form that is seen- characteristics such hair colour, given by genotype
meaning of “haplotype”
DNA variations (polymorphisms) that tend to be inherited together from a single parent
meaning of incomplete dominance
Incomplete dominanceis a form of intermediate inheritance in which one allele for a specific trait is not completely expressed over its paired allele. This results in a third phenotype in which the expressed physical trait is a combination of the phenotypes of both alleles.
For example, If you had a blue allele and a yellow allele then the outcome would be neither blue or yellow but would be green due to mixture of both and none being dominant over the other, because the outcome is green, which is a 3rd phenotype
meaning of homozygote
same
meaning of heterozygote
different
meaning of co-dominance
both alleles contributing to the phenotype
for example if you had blue and yellow, the outcome of a co-dominance would be blue and yellow (blue flower with yellow dots)
example of disease caused by dominant mutation
> dwarfism
> huntingtons disease
where is the mutation that causes dwarfism?
Fibroblast growth factor receptor 3 (FGFR3) gene which causes an abnormality of cartilage formation
Huntington’s disease gene info
> gene has CAG repeats (polyglutamine)
normal gene has 6-39 CAG repeats
disease gene has 35-121 CAG repeats
possible molecular explanations of dominant mutations
> not enough protein made if only one gene copy is active
> genes constantly expressed
meaning of Epistasis
interaction of two or more genes on separate chromosomes which effect the phenotype
