Answer: C) Apical
Explanation: An epithelium has a free surface, the apical surface, exposed to the outside, and an attached surface, the basal surface, resting on the underlying connective tissue.
<span>When cells were first taken from Henrietta Lacks, she was suffering from cervix cancer. Henrietta Lacks was a woman whose cervix cancer cells were used as the source of the HeLa cell line nowadays used in medical research. During treatment for cervical cancer in 1951, the cells were taken without her knowledge. The cells were cultured by George Otto Gey who created the HeLa cell line.</span>
The kidneys filter the blood to remove wastes and produce urine. The ureters, urinary bladder, and urethra together form the urinary tract, which acts as a plumbing system to drain urine from the kidneys, store it, and then release it during urination.
