In Mendelian genetics, what does a "true-breeder" represent?

• A. A plant that produces hybrid offspring
• B. A plant that consistently produces the same trait
• C. A plant with varied traits
• D. A plant that requires cross-fertilization

Answer: (B)

A true-breeder is defined as an organism that, when self-fertilized or bred among like individuals, produces offspring that consistently exhibit the same traits across generations. This characteristic means that the genetic makeup of a true-breeder is homozygous for those traits. For instance, if a true-breeding plant has purple flowers, all offspring produced from self-pollination of this plant will also have purple flowers, demonstrating stability in the trait being expressed.

This concept is fundamental to Mendelian genetics, as it allows researchers to understand inheritance patterns and the effects of dominant and recessive alleles. In contrast, options referencing hybrid offspring, varied traits, or cross-fertilization do not align with the true-breeding definition, as true-breeding organisms are characterized by their predictability in trait inheritance, rather than variability or dependence on cross-fertilization.