Final answer:
The term that best describes the phenomenon where certain traits appear in offspring more frequently and do not show predictable combinations with other traits in hybrid pea plants is termed 'independent assortment.' This concept, along with 'dominance,' were key findings from Gregor Mendel's pea plant experiments. The correct option is c Independent assortment
Step-by-step explanation:
When Gregor Mendel crossed hybrid pea plants, he observed two significant phenomena. Firstly, the trait that was expressed in the hybrid offspring (such as yellow peas) is referred to as dominant, and the trait that was not expressed (like green peas) is called recessive. This observation describes the concept of dominance. Secondly, Mendel's work with multiple traits led him to formulate the principle of independent assortment. This principle explains why not all tall plants had green peas and not all short plants had yellow peas, meaning that each pair of alleles segregates independently during gamete formation.
Dominance refers to the observed pattern where one characteristic overshadows another in hybrid offspring, while independent assortment means that different characteristics segregate and recombine independently, leading to a variety of combinations in the offspring. The correct option is c Independent assortment