what is a trait in biology

In biology, a trait is a specific characteristic of an individual that can be described or measured. Traits can be determined by genes, environmental factors, or a combination of both. They can be physical, such as hair color, leaf shape, or height, or behavioral, such as bird nesting. Traits can be qualitative, such as eye color, or quantitative, such as blood pressure. A given trait is part of an individuals overall phenotype, which is the observable traits expressed by an organism. In genetics, traits are controlled by genes that one inherits from both parents. An organisms underlying genetic makeup, consisting of both physically visible and non-expressed alleles, is called its genotype. The observable traits expressed by an organism are referred to as its phenotype.