Genes determine traits such as skin, hair, or eye color, and each gene consists of two alleles, one from the mother and the other from the father. Alleles can either be dominant or recessive. The terms dominant and recessive describe the inheritance patterns of certain traits, and they describe how likely it is for a certain phenotype to pass from parent to offspring. Here are some key points about dominant and recessive traits:

Dominant traits:

• Dominant alleles show their effect even if the individual only has one copy of the allele (also known as being heterozygous) .
• Dominant traits are always expressed when the connected allele is dominant, even if only one copy exists.
• Dominant allele is denoted by a capital letter.

Recessive traits:

• Recessive alleles only show their effect if the individual has two copies of the allele (also known as being homozygous) .
• Recessive traits are expressed only if both the connected alleles are recessive. If one of the alleles is dominant, then the associated characteristic is less likely to manifest.
• Recessive allele is denoted by a small letter.

Dominant and recessive inheritance are useful concepts when it comes to predicting the probability of an individual inheriting certain phenotypes, especially genetic disorders. However, it is important to note that there is no universal mechanism by which dominant and recessive alleles act. Dominant alleles do not physically “dominate” or “repress” recessive alleles. Whether an allele is dominant or recessive depends on the particulars of the proteins they code for.