Answer: a) genetic
b) environmental
Step-by-step explanation:
Phenotype is a function of genotype and environment
P=G+E
Where P= phenotype
G=Genotype
E=Environment
The phenotype of an individual i.e what is seen or expressed is a product of the gene he or she carries and the environment they occupy.
Gene is the genetic makeup of an individual.
The Identical and fraternal twin are products of their gene and the environment such as uterine environment, parenting style they grow, Identical twins have 100% of identical genes while fraternal twin have 50% gene in common
Hence, the difference is a function of their genetic makeup and the environment they grow.
Culture and evolution can also be regarded as part of the environment.