I believe it is organ level
The history of life on Earth began about 3.8 billion years agohumans have been around for a mere 0.004% of the Earth's history
Answer: Codominance
Explanation:
Since neither type A blood nor type B is dominant over the other (i.e both are codominant), the offspring of both parents will be with type AB blood.
Thus, codominance explains how the two alleles are present in the Heterozygous individual IAIB, showing they are both fully expressed.
It may either be man#1 with blood group b or man#2 with blood group ab
The scientist can conclude that the plants that were used in this experiment contained both a dominant and recessive allele. That the plants were hybrids which causes the off springs to have a 3:1 ratio.