Which concept includes both homozygous and heterozygous traits?

The concept that includes both homozygous and heterozygous traits is genotype. Genotype refers to the genetic makeup of an organism, specifically the alleles that it possesses for a particular trait. When an organism has two identical alleles for a trait, it is referred to as homozygous. Conversely, when it has two different alleles for the same trait, it is considered heterozygous. Since genotype encompasses all possible combinations of these alleles—whether both are the same (homozygous) or different (heterozygous)—it serves as the foundational concept that describes an organism's genetic characteristics.

Phenotype, on the other hand, pertains to the observable traits or characteristics of an organism that result from the interaction of its genotype with the environment. Recessive and dominant refer to the specific expressions of alleles but do not encompass the overall genetic combinations that signify an organism's genotype. Thus, genotype is the correct answer as it encompasses both homozygous and heterozygous traits.