Course: Science Subtest II
Lesson: Genetics and Evolution
Topic: Inheritance of Traits      Page 10 of 18  

Environmental Influences on Genetic Expression

Two organisms with the same genetic makeup can have very different traits. For example, identical twins can vary in how they look, act and develop . This is because appearance and behavior can be modified by environmental conditions.For example, your parents provided the genes that determined your potential height. However, environmental factors, such as your diet, influenced how your genetic potential was "expressed".

Genotype is the genetic makeup of an organism

Phenotype is the outward expression of the environmental effects on an organism's genotype. Phenotype includes all of an organism's actual traits such as its morphology, development, behavior.

Identical brothers who have the same genotypes. Differences in their appearances are due to different environmental factors such as diet, exercise, exposure to disease, etc..