According to Mendel's First Law of Segregation, what is true about alleles?

Mendel's First Law of Segregation states that individuals possess two alleles for any particular trait (gene), one inherited from each parent. During the formation of gametes (sperm and egg), the alleles segregate so that each gamete carries only one allele for each trait. This principle is foundational in understanding inheritance patterns, as it explains that traits are not blended but instead maintain distinct alleles that can be passed on. Therefore, the statement about individuals possessing two alleles for any trait accurately reflects Mendel's findings and directs attention to how genetic variation is achieved through the separation of alleles during gamete formation.

Other options do not align with Mendel's principles. For instance, alleles are not always inherited together, as they can segregate independently depending on the traits. The expression of alleles in a dominant-recessive manner refers to how traits are phenotypically expressed rather than how they are inherited. Additionally, it is not true that all offspring will inherit the dominant allele, since offspring receive one allele randomly from each parent, which can be either dominant or recessive.