Final answer:
The root 'aden-' is related to glands, seen in terms such as 'adrenocorticotropic hormone (ACTH)' and 'adrenal gland'. 'Algae-' is related to algae and not glands.
Step-by-step explanation:
The word root that means 'gland' is 'aden-'. This can be seen in terms such as adrenocorticotropic hormone (ACTH), which is a hormone produced by the pituitary gland that stimulates the adrenal glands. Other terms related to the gland include adrenal gland, adrenal cortex, and adrenal medulla. These terms all relate to the glands and their functions in the human body. It's worth noting that the root 'algae-' relates to algae, such as in the term unicellular photosynthetic algae, and is not associated with glands.