Multiple alleles
Blood types are controlled by multiple alleles.
Some of the human traits determined by multiple alleles would be hair color, hair texture, eye color, built, physical structures, etc. One notable and most common example of multiple alleles in humans would be of the blood groups.
Traits controlled by a gene with multiple alleles can vary in terms of expression or phenotype. For example, human blood type (A, B, AB, O) is controlled by a gene with multiple alleles. The different alleles can result in different phenotypes (A, B, AB, O) for the same trait.
The ABO blood groups in humans are controlled by multiple alleles.
Human blood type is determined by codominant alleles.
In humans good examples are blue eyes, blonde hair, type "O" blood, sickle cell anemia, and hemophilia.
Blood type in humans is an example of multiple alleles.
Eye color Height Hair texture Blood type
It depends on which context, and what you would define as human traits: If you are referring to mythology in that humans become vampires, then they share many traits with humans, as they were originally that species. Such traits as human skeletal structure, musculature, facial features, hair, eyes, ears, the capacity to breath and digest nutrients (although the food source would be different (i.e. blood). When referring to other species which require blood ingestion (for whatever reason, for example: to postpone coagulation of their own blood), such as vampire bats and various insects, the similarities to humans decreases. Taking into account vampire bats, they do share more human traits as opposed to insects, such as a skeletal and muscular structure and similar organs in which to receive sensory information, as well as beating hearts and a vascular system. However, given their physiology, these traits would only be considered as human traits in the sense that humans have them.
In the Korean culture, personality is often associated with a person's blood type. For example, people with blood type A are thought to be more inclined to being perfectionists. Blood type B people are thought to be more creative and optomistic. The personality traits associated with blood type AB are cool, controlled, and rational. And lastly people with blood type O are ambitious and self-confident.
Codominance occurs when two different alleles for a gene are both expressed in the phenotype of a heterozygous individual. This results in a blending or mixing of the traits associated with each allele, rather than a dominant-recessive relationship. An example is blood type in humans, where the AB blood type is codominant, expressing traits of both A and B alleles.
Traits governed by multiple alleles are controlled by three or more alleles, rather than two. An example in humans is the ABO blood group system. There are three alleles in the ABO blood group system, IA, IB, IO. These three alleles can produce six genotypes, AA, AO, BB, BO, AB, OO. These genotypes can produce four different phenotypes, A (genotypes AA or AO), B (genotypes BB or BO), AB, (genotype AB) and O (genotype OO).