Which statement best explains how the genetic code is considered universal?

• A. The genetic code varies significantly between different species, leading to different amino acids being encoded by the same codons.
• B. The genetic code is the same in all living organisms, allowing for the same amino acids to be encoded by the same codons.
• C. The genetic code is unique to each individual organism, ensuring that no two organisms have the same genetic sequence.
• D. The genetic code is only applicable to eukaryotic organisms, excluding prokaryotes from its universality.

Answer: (B)

Verified step by step guidance

1. Understand the concept of the genetic code: The genetic code refers to the set of rules by which information encoded in genetic material (DNA or RNA sequences) is translated into proteins (amino acid sequences) by living cells.
2. Recognize the universality of the genetic code: The genetic code is nearly universal, meaning that the same codons specify the same amino acids in almost all organisms, from bacteria to humans.
3. Identify the exceptions: While the genetic code is universal, there are a few exceptions, such as in mitochondria and some protozoa, where slight variations occur. However, these exceptions are rare and do not significantly alter the universality of the genetic code.
4. Consider the implications of universality: The universality of the genetic code suggests a common evolutionary origin for all life on Earth, as it allows for the same genetic instructions to be used across different species.
5. Evaluate the statements: The statement 'The genetic code is the same in all living organisms, allowing for the same amino acids to be encoded by the same codons' best explains the universality of the genetic code, as it highlights the consistent encoding of amino acids across different species.