Traits passed from parents to offspring via genetic material are called **inherited traits**. Gregor Mendel, the "Father of Genetics", selected the **Garden Pea plant (*Pisum sativum*)** for his research because it possessed distinct, easily identifiable contrasting characters (like tall vs. short, round vs. wrinkled seeds).
A cross analyzing the inheritance of a single pair of contrasting features (e.g., Plant Height):
Mendel crossed plants tracking two different traits simultaneously (e.g., Round Yellow seeds × Wrinkled Green seeds). In the F2 generation, traits segregated independently to produce a unique phenotypic ratio:
Humans carry 23 pairs of chromosomes. The 23rd pair dictates biological sex:
When a sperm fertilizes an egg, an X-bearing sperm creates a female child (XX), while a Y-bearing sperm creates a male child (XY). Thus, the biological sex of a child is determined entirely by the paternal gamete.
Law of Independent Assortment: When two pairs of traits are combined in a hybrid cross, the inheritance of one pair of characters is entirely independent of the inheritance of the other pair. This allows traits to mix freely, creating completely new combinations in later generations.