Australian Year 10 Biology Practice Test

The term that describes an allele that is masked when a dominant allele is present is known as a recessive allele. In genetics, alleles are variants of a gene that can produce different traits. When an individual has one dominant allele and one recessive allele for a particular trait, the dominant allele will determine the phenotype, or observable characteristics, while the effect of the recessive allele will not be expressed in the presence of the dominant one. This is a fundamental concept in Mendelian inheritance, where the expression of dominant and recessive traits can be observed in offspring. For example, if an organism inherits a dominant allele for a trait, such as tall height in plants, and a recessive allele for short height, the organism will exhibit the tall phenotype because the dominant allele overshadows the effects of the recessive allele. Understanding this distinction helps explain how traits are passed on and expressed in different generations.