You can't have a carrier with a dominant pedigree because other wise than individual or organism would be afflicted by the gene and render them incapable of being a carrier. A carrier is an individual/organism that has a normal phenotype (meaning it is not afflicted by said gene) but is carrying the gene that could cause disease or whatever the affect may be. In this case the gene would have to be homozygous recessive to be expressed. Hopefully this helps!
Answer:
1) Aa refers to the heterozygous of the genes. In this gene, both allele are different from one another.
2) AA is a gene which is homozygous in nature. Homozygous means that both allele are the same. Capital letters i. e. AA is used for the trait that is dominant.
3) aa is a gene which is homozygous in nature. Lower case letters i. e. aa is refer for the trait that is recessive.
In geometry the base is the side or face of a geometric figure to which an altitude is drawn,
Mutualism
Explanation: a relationship between two species of organisms in which both benefit from the association.