What is true about recessive inheritance?

In recessive inheritance, a trait associated with a recessive allele will only be expressed in the phenotype when an individual possesses two copies of that allele, making it homozygous for the recessive trait. This means that both gene copies, one inherited from each parent, must carry the recessive allele for the associated trait to manifest. If an individual has only one recessive allele (and one dominant allele), the dominant trait will prevail, and the recessive trait will not be expressed.

The incorrect choices include aspects that do not accurately represent the principles of recessive inheritance. For instance, the statement about needing only one recessive allele is incorrect, as it is only in the presence of two recessive alleles that the trait is expressed. Additionally, the assertion that recessive inheritance can only involve monogenic disorders is misleading; recessive traits can appear as part of polygenic traits as well. Finally, stating that recessive inheritance always leads to severe conditions does not hold true, as many recessive traits may be benign or not lead to significant health issues.