geno

Learn this one with the hat on the next word, not this one.

• geno, no hat, hard g as in go - a gene.
• ĝeno, with the circumflex, the sound of English j in jam - bother, trouble, annoyance. It is the noun of ĝeni, to disturb, which you met at rank 869.

That is a minimal pair separated by one diacritic, and it is the kind that actually bites, because both words are common enough to turn up in the same paragraph and neither is nonsense in the other's place. Liaj genoj is his genes. Lia ĝeno is his annoyance. Written without the hat, in the x-system, they are geno and gxeno and the difference is obvious; written carelessly without either, they collapse, which is one of the plainer arguments for writing the diacritics properly.

Geno is regular international vocabulary and its family builds itself: genetiko genetics, genetika genetic, and genaro the genome, with the collective suffix -ar- doing exactly what it does in arbaro and vortaro. One more to keep out of the set: genio is a genius, a different root that only looks like a relative.

Scientific Esperanto is a real register with real conventions, and this word is a good example of how it works: the specialist term arrives whole from the international form, and the ordinary grammar of the language then applies to it without exception. This chapter's article on scientific Esperanto sets out how the rest of that vocabulary is built.