Final answer:
Peptide hormones are the most variable in size, produced in the Rough ER, and packaged in the Golgi for vesicular release. They are water-soluble and require vesicular transport, unlike lipid-soluble lipid-derived hormones like steroids.
Step-by-step explanation:
The hormone class that varies the most in size, is produced in the Rough Endoplasmic Reticulum (Rough ER), and is packaged in the Golgi apparatus before being released in vesicular form is the peptide hormones. Peptide hormones are not lipid-soluble and hence are unable to diffuse across the plasma membrane.
Furthermore, these hormones are water-soluble, and they are produced as larger preprohormones in the Rough ER, then cleaved into prohormones, folded into their active conformation, and finally packaged into vesicles by the Golgi apparatus for release into the bloodstream. In contrast, lipid-derived hormones like steroids are lipid-soluble and can pass directly through cell membranes without the need for vesicular transport. The primary class of lipid hormones in humans is the steroid hormones, such as estradiol and testosterone, which are derived from cholesterol and insoluble in water.