How many different phenotypes are possible in a one gene/three allele system that displays codominance to each other?

3 homozygous and 3 heterozygous combinations. Each unique combination of two alleles results in a distinct phenotype. Possible combinations are: 
a1/a1 
a1/a2 
a1/a3 
a2/a2 
a2/a3 
a3/a3

1. the energy lost to disorder metabolism     -entropy

2. related to or possessing motion potential     -kinetic

3. all of the chemical reactions in an organism required for maintenance of the processes of life entropy     -metabolism

4. possible; ability to go into action or perform work kinetic     -potential

5. the study of energy and its transformations thermodynamics     -thermodynamics

ans.

gregor john mendel is known for study of inheritance in pea plants. he used garden pea plant for his study, having alternative traits for various characters. he performed cross-breeding in pea plants to check how characters are transmitted between parents to offspring, such as cross between pure tall and pure dwarf plant. mendel studied the inheritance patterns in pea plants for various generations.

thus, the correct answer includes options and f).