Mendelian Patterns of Inheritance Flashcards
what is a phenotype
the physical trait of the gene
what is the genotype
the gene e.g. (BB) (Bb) (bb)
Provide an example of a trait which may be inherited from multiple alleles
In most cases, a gene has only two alleles. There are more than two potential alleles for multiple allele traits. You’d still have only two copies of the gene, one per parent, however the population will have a variety of alleles. A good example is blood type in dogs, in which there are three alleles: iA, iB or i. As a result, a person can be iAiB, iAi, iBi, or ii.
Which chromosome are sex-linked genes usually carried on?
It is the sex chromosomes, sex-linked features are carried, X or Y
what is Incomplete dominance?
The two versions (alleles) of the same gene are not expressed as dominant or recessive; rather, the expressed trait is a combination of both alleles e.g. white horse and brown horse have baby, baby is a pale brown colour/ roan
what is Codominance
Two versions (alleles) of the same gene are expressed separately. One trait is not dominant over the other and so both traits appear e.g. brown cow and white cow have baby, baby is brown and white coated
what is Polygenic inheritance
The inheritance of traits that are determined by more than one gene. When several genes, known as polygenes, are expressed together, they produce unique features. Dog size can be an example of this.
what is Multiple allele?
Multiple allele traits have more than two possible alleles. You would still only have two copies of each gene, one from each parent, but there will be a range of possible alleles within the population. An example of this is blood type in humans, where there are three possible alleles, iA, iB or i.An individual can therefore be iAiB, iAi, iBi or ii.
