Variations in heredity (genetics) Flashcards
what are 3 of mendels laws? (name)
- the Law of Dominance
- the Law of Segregation
- the Law of Independent Assortment
what is the law of dominance?
In a cross of parents that are pure for contrasting traits, only one form of the trait will appear in the next generation (F1). (1 alelle dominates over the other)
Offspring that are hybrid for a trait will have only the dominant trait in the phenotype.
But the recessive trait will still be passed down
the law of segregation?
offspring/organism inherit 2 copies of genes, one from each parent
parents can only give 1 copy of their genes to a gamate (sex cell)
the law of indepedent assortment
-> all allelles of different traits are distruibted to sex cells and offspring independently
-> there is no links between allelles
-> everything is randomized
what is the spectrum of dominate and what are the 3 types of dominances
Alleles can show different degrees of dominance and recessiveness in relation to each other
complete dominance -> incomplete dominance -> co-dominance
what is complete dominance?
1 allele is complete dominate over the other, and if present it will always be physically expressed
what is incomplete dominance?
-> neither alleles dominate each other, therefore both express the indivdual and are partially expressed
-> a “mix happens”
–> ie: red + white = pink (red and white are alleles that are partially dominate
codominance?
alleles are both dominate and if present will be expressed fully no matter what, causing a third phenotype
ie: black cow + white cow = spotted cow
what are blood types (type of inhertiance)
what are the 4 blood types and their alleles?
blood types are an example of complete dominance and codominance
Type A (I^A I^A, I^A i)
Type B (I^B I^B, I^B i)
Type AB (I^A I^B)
Type O (ii)
Who is the universal recipant of blood? Who is the universal donar?
Type AB can receive anytype of blood
Type O can give anytype of blood
What is polygenic inheritance?
Phenotypes determined by the additive effects of 2 or more genes on a single character phenotypes