Final answer:
The correct option is False. It is false that a single codon can encode multiple amino acids. While the genetic code is unambiguous with each codon specifying only one amino acid, it is redundant, meaning multiple codons can encode for a single amino acid. The genetic code is nearly universal across all organisms.
Step-by-step explanation:
For the genetic code, it is false that multiple amino acids can be encoded by the same codon. Each codon within the genetic code is unique and specifies a single amino acid; hence, the genetic code is said to be unambiguous. This characteristic is crucial for maintaining the fidelity of protein synthesis. However, the genetic code is also redundant, meaning that a single amino acid can be specified by more than one codon. For example, the amino acid threonine is encoded by four different codons: ACU, ACC, ACA, and ACG.
The start codon, usually AUG in eukaryotes, serves a dual purpose. Not only does it signal the commencement of protein synthesis by establishing the correct reading frame, but it also encodes the amino acid methionine. This dual function signifies the well-designed efficiency of the genetic code in initiating the translation process.
The universality of the genetic code is one of its remarkable features. With few exceptions, the same codon encodes the same amino acid in different organisms, whether they are plants, animals, or bacteria. For instance, the codons for tyrosine are the same in humans as they are in plants. This commonality suggests that the genetic code was an early evolutionary development, maintained across species over time.