It's important to note that the term "helix" itself doesn't necessarily imply double strandedness. Here are some examples of single-stranded helix molecules:

* Single-stranded DNA (ssDNA): While DNA is usually double-stranded, it can exist in a single-stranded form in certain biological processes.

* RNA: RNA is typically single-stranded, though it can sometimes form double-stranded regions.

* Some proteins: While not as common as DNA or RNA, certain proteins can fold into helical structures.

So, the term "single-stranded helix" encompasses a variety of different molecules.