Yes.
There are some traits like skin color that are controlled by multiple genes within an individual.
There is also a problem called nondisjunction that causes a gamete to wind up with two chromosomes instead of one. The offspring then has three chromosomes and three genes for each trait carried on that chromosome.
(Nondisjunction of the 21st chromosome causes Down syndrome, so someone with Down Syndrome has three genes for each trait on the 21st chromosome.)
Single gene diseases only effect one typeof gene where im a complex genetic disease many genes are effected. An example of a single gene diseas is sickle cell anemia. Cancer would be an eexample of a complex gene disease.
These are terms used in a punnet square. Dominant is the Phenotype, or a gene that is predicted to be expressed in a heterozygous being- the offspring of two beings with different traits. Recessive is the Genotype, or a gene that is predicted to be hidden in the Deoxyribose Nucleic Acid, (DNA,) of a heterozygous being. Sometimes there is Codominance, where both genes are fully expressed, or incomplete dominance, where the genes are mixed, and are partially expressed.
Codominance means that neither allele can mask the expression of the other allele. An example in humans would be the ABO blood group, where alleles A and alleles B are both expressed.
genetic traits
If a point mutation occurs in a location that is not critical to the structure and function of the protein, it will not change the way the gene is expressed. Also, since most amino acids have more than one codon, if the point mutation resulted in a codon for the same amino acid without the mutation, it will not change the way the gene is expressed.
heterozygous gene. In this situation, both alleles are different and both are expressed, resulting in a blending or mixing of their traits.
C. Alleles
Dominant traits are expressed when just one copy of the gene is present, while recessive traits require two copies to be expressed. Dominant traits mask recessive traits when they are both present.
Dominant traits are characterized by a single copy of a gene being sufficient to express a certain trait, whereas recessive traits require two copies of the gene (one from each parent) for the trait to be observed. Dominant traits typically mask the expression of recessive traits when both are present.
Dominant Traits
This is known as a dominant trait. Dominant traits require only one copy of the gene to be expressed in an individual. The presence of one dominant allele is sufficient to display the trait, even if the individual also carries a different allele for the same gene.
These traits are called dominant traits. They will overcome the recessive gene and the dominant trait will be expressed. A recessive gene needs two alleles present in its genotype to be expressed.
It is a dominant trait. You only need one gene of a dominant trait for that trait to be expressed. You need two copies of the recessive trait in order for the trait to be expressed.
Dominant trait due to doominant gene (as against recessive trait)
Dominant genes will always be expressed however recessive genes would need to be inherited from both parents
Traits that typically will only be expressed in offspring if they inherit two copies of the genes for the trait are called Recessive traits. - Nikkkki
A pattern where both versions, or alleles, of a gene are fully expressed in the phenotype is called codominance. In this scenario, the traits associated with both alleles are visible in the offspring. An example is the ABO blood group system, where an individual can have both A and B antigens expressed on their red blood cells if they inherit both A and B alleles.