University of Central Florida (UCF) BSC2010C Biology I Practice Exam 3

RNA differs from DNA primarily in its structure and some of its nucleotide components. One significant difference is that RNA is typically single-stranded, whereas DNA is double-stranded, forming a double helix. This single-stranded nature of RNA allows it to fold into various shapes and perform diverse functions within the cell.

Additionally, RNA contains uracil instead of thymine, which is one of the key distinctions between the two nucleic acids. In DNA, adenine pairs with thymine, while in RNA, adenine pairs with uracil. This substitution is important for the different functional roles that RNA plays in cellular processes, such as transcription and translation during protein synthesis.

While RNA is found primarily in the nucleus during transcription and then in the cytoplasm during translation, it is not restricted solely to the nucleus. Furthermore, RNA plays a crucial role in protein synthesis, acting as a messenger between DNA and the ribosomes, where proteins are synthesized. Thus, the choice highlighting the single-stranded structure of RNA and the presence of uracil accurately captures these fundamental differences.