For example, the gene for seed shape in pea plants exists in two forms, one form or allele for round seed shape (R) and the other for wrinkled seed shape (r). A true-breeding round seed plant would be (RR) for that trait and a true-breeding wrinkled seed plant would be (rr).
Chromosomes and Gender
Chromosomes are long, stringy aggregates of genes that carry heredity information. Gender is determined by the presence or absence of certain chromosomes.
Law of Segregation
The principles that govern heredity were discovered by a monk named Gregor Mendel in the 1860's. One of these principles is now called Mendel's law of segregation.
This principle of heredity formulated by Gregor Mendel states that traits are transmitted to offspring independently of one another.