Which of the following statements best describes a feature of tRNA?Group of answer choicestRNAs help position primase molecules on the leading strandtRNAs consist of a single strand of RNA folded into a precise 3D structureThere is at least one tRNA molecule for each strand of DNATheir catalytic activity is dependant on the attached amino acid PreviousNext

The statement that best describes a feature of tRNA is "tRNAs consist of a single strand of RNA folded into a precise 3D structure".

tRNA, or transfer RNA, is a type of RNA molecule that helps decode a messenger RNA (mRNA) sequence into a protein. tRNAs function at specific sites in the ribosome during translation, which is a process that synthesizes a protein from an mRNA molecule.

Here's a step-by-step explanation of how tRNA works:

1. Each tRNA has a specific anticodon, a sequence of three bases that is complementary to a codon in the mRNA sequence.

2. The tRNA recognizes the codon on the mRNA by using its anticodon, and binds to it.

3. The tRNA has an amino acid attached to it, which is added to the growing protein chain when the tRNA binds to the mRNA.

4. The tRNA then leaves the ribosome, and goes back to the cytoplasm to attach to another amino acid, and the process repeats.

So, the statement "tRNAs consist of a single strand of RNA folded into a precise 3D structure" is correct because it is this 3D structure that allows the tRNA to carry out its function. The shape of the tRNA molecule is a result of specific base pairing, and it allows the tRNA to recognize the mRNA codon and bind to it.

The other statements are not correct descriptions of tRNA. tRNAs do not help position primase molecules on the leading strand, there is not one tRNA molecule for each strand of DNA, and their catalytic activity is not dependent on the attached amino acid.