Inheritance Of Blood Groups Flashcards
how many potential blood types do humans have and what are they
- humans have 4 potential blood group types
- they are a, o, b and ab
how many different alleles can the gene for blood type have and what are they
- there are 3 different alleles
- they are Ia Ib and Io
what is the relationship between la and lb alleles
they are co dominant with each other
what does the co dominance between alleles la and lb mean if an individual inherits them
when someone has both of those alleles (genotype la and lb) they will have the blood type ab
what does co dominant mean
that one allele isnt dominant over the other one
which allele responsible for blood type is recessive
lo
what blood type would you get if you were to have in individual with an lo and la genotype
if someone had the genotype of lo,la you would only see the effect of la because la is dominant over lo (lo is recessive)
- so their blood type would be a
when would someone have the blood type of o
if they had two of the recessive alleles, lo lo
what is different when drawing a genetic diagram for blood type compared to other factors such as sex
- when you have worked out the potential genotypes, predicting the potential phenotypes is harder
- because you need to remember how the different alleles of blood type interact with each other, like co dominance
what would be the phenotype of a man with the genotype la lo
- the la is dominant over the lo
- they are different alleles
- so his phenotype is heterozygous blood group a
what would be the phenotype of a woman with the genotype lb lo
- the lb is dominant over the lo
- they are different alleles
- so her phenotype is heterozygous blood group b
if a man with the phenotype of heterozygous blood group a and a woman with the phentype heterozygous blood group b were to have off spring, what would be punnett square of their different genotype possibilities look like
- man is heterozygous blood group a
- woman is heterozygous blood group b
- meaning man has gentype of la lo
- meaning woman has gentype of lb lo
- combinations of gametes alleles are:
- la lb (group ab)
- la lo (group a)
- lo lb (group b)
- lo lo (group o)
if a man with the genotype la lo and a woman with the gentype lb lo were to have off spring what would be chances of the child having one of the four blood groups
- the child could have any one of the four different blood groups
- so the child had an equal chance (25% or 1 in 4 chance) of having each blood group
why is someone with the blood type o so rare
because the allele coding for the blood type (lo) is recessive and is usually dominated by the other alleles la and lb
