From LibreTexts, under CC BY-SA 3.0, as the source states it; its equations are written in TeX, which the PDF shows typeset. This page at LibreTexts.
4.S: Genetic Analysis of Single Genes (Summary)
Opening the book…
A diploid can have up to two different alleles at a single locus. The alleles segregate equally between gametes during meiosis.
Phenotype depends on the alleles that are present, their dominance relationships, and sometimes also interactions with the environment and other factors.
Classical geneticists make use of true breeding lines, monohybrid crosses, Punnett squares, test crosses, reciprocal crosses, and the chi-square test.
Sex-linked genes are an exception to standard Mendelian inheritance. Their phenotypes are influenced by the type of sex chromosome system and the type of dosage compensation system found in the species.
The male/female phenotype (sex) can be determined by chromosomes, genes, or the environment.