Final answer:
The statement that a trait is a specific characteristic varying among individuals is true; traits are variations in genetic makeup resulting from the unique combination of inherited genes, which can be influenced by Mendelian or polygenic inheritance.
Step-by-step explanation:
The statement 'A trait is a specific characteristic that varies from one individual to another' is true. Traits are indeed variations of characteristics that can differ among individuals. For instance, consider the characteristic of hair color; its traits could be blonde, brown, or black. These traits result from the combination of genes inherited from both parents. These genes are located on chromosomes, and each parent contributes one chromosome to the pair, making the genes themselves unique in every individual. As a result, even a slight alteration in the sequence of nucleotides within a gene can lead to a different trait being expressed.
Mendelian genetics further exemplifies this concept. Gregor Mendel's classic experiments on pea plants demonstrated that traits, such as flower color, can be passed from parents to offspring and can vary (purple vs. white flowers). These traits can be dominant or recessive, with the dominant trait being the one that is expressed in the presence of another allele. Mendelian traits are influenced by discrete alleles and can exhibit patterns of inheritance that follow Mendel's laws. However, many human characteristics, such as height, are polygenic, meaning they are controlled by multiple genes, leading to a range of phenotypes.