Move over X files; here comes the X word trials!

Words: X chromosome, xenophobia, x-ray, xylem

X chromosome determines, specie gender everywhere.
But if scientists' used an x-ray,
The same results they'd get, I swear.
Without a lab, without test tubes,
Minus scientific laws and rules,
The variety tested would remain,
Plus, that testing's advantage,
Would be a huge financial gain.

And from xenophobia, I guess I suffer,
To some degree, most acutely,
I'm leary of strangers of foreign descent,
I fear danger quite absolutely.

A xylem conducts plants' water 'n salt,
From roots, to stems 'n leaves,
Like people, plants have vessels,
Which bolsters my reason to believe.