Question

how is genotype related to phenotype? what else contributes to phenotype?

Answer 1

Genotype are the pair of genes present in an organism DNA that are responsible for a particular trait.

And a phenotype is the physical expression of those genotypes.

For example a tall looking pea plant can have either same genotype (TT) or different genotypes (TT and Tt) although they have same phenotype (tall). Similarly a tall and a dwarf pea plant have two distinct genotypes TT/Tt and tt respectively.

Other than genotype environmental factors like temperature, humidity nutrition and mutagens affect the phenotype. They affect which of animal genes are expressed and which are suppressed, which ultimately affects the phenotype of an organism.