In: Anatomy and Physiology
Let us assume the gene controlling the Height as T gene and the alleles of the gene as T and t
So, genotype of the true breeding homozygous Tall pea plant will be TT
genotype of the true breeding homozygous short pea plant will be tt
TT and tt are the parental (p) generation)
F1 generation is obtained when the parental generation are crossed
TT X tt
Gamete from the TT will be T
Gamete from the tt will be t
so punnet square of F1 generation will
t | t | |
T | Tt | Tt |
T | Tt | Tt |
genotype ratio is 1 ,all the offsprings will be Tt
phenotypically they will be Tall pea plant(due to the dominance of tall allele over short allele)
F2 generation is obtained when the F1 is crossed together, that is
Tt X Tt
Gamete will T and t
Ff2 generation punnet square
T | t | |
T | TT | Tt |
t | Tt | tt |
Genotype ratio will be TT :Tt: tt -----------> 1:2:1
phenotyep ratio tall : small -----------> 3: 1
PATTERN OF INHERITANCE SHOWN BY THE ABO BLOOD GROUP IS CODOMINANCE
That is in ABO blood grouping ,When the Alelle of the A gene and allele of B group come together , Both the gene get dominated and the blood group will AB group.