Explanation: Genes are the specific set of nucleotides (DNA) in a particular order that make up a chromosome.
Alleles that show expression of one gene from another is incorrect as an answer because genes are part of a genetic makeup therefore alleles that show an expression of one gene from the other are not genes at all.
Dominant alleles being expressed do not fit the criteria of being grouped as genes. Genes also include recessive traits that may happen to be inherited by future offspring.
Small subtle changes do not constitute as genes because the changes can be influenced by external factors and DNA can rarely be altered by these.
The specific sequences of DNA in an organism are what makes up its genes. The DNA making up the nucleotide and it being arranged in a specific order to making up a chromosome.
