Semen has a(n) ___ pH

A. 3, 6, 2, 1, 5, 4: Urine formation begins in the nephron and enters the collecting duct for final concentration. Fluid then flows into the minor calyx, then the major calyx, through the ureter to the bladder, and finally exits the body via the urethra. This sequence accurately reflects the anatomical flow of filtrate.

B. 2, 1, 3, 6, 5, 4: This sequence incorrectly places the minor and major calyces before the nephron and collecting duct. Filtration must occur in the microscopic nephron unit before any fluid can enter the macroscopic drainage system of the renal pelvis. The calyces are receiving structures, not forming structures.

C. 3, 1, 2, 6, 5, 4: This arrangement suggests that the major calyx precedes the minor calyx and collecting duct, which is anatomically impossible. The minor calyces merge to form major calyces, which then form the renal pelvis. The collecting duct is the final microscopic segment before the calyces.

D. 6, 3, 2, 1, 5, 4: The collecting duct receives fluid from the distal convoluted tubules of the nephron, so the nephron must come first in the sequence. While both are microscopic, the nephron is the site of initial ultrafiltration and tubular processing. The sequence must start at the renal corpuscle.

A. a tertiary follicle: This term refers to a mature, fluid-filled antral follicle that contains the oocyte before it is released. While the tertiary follicle is the structure that ruptures, it is the cellular unit within it that is ovulated. The follicle remains in the ovary to become the corpus luteum.

B. a secondary follicle: A secondary follicle is an immature stage of follicular development characterized by the presence of a small, fluid-filled antrum. It has not yet reached the maturity required for ovulation. It contains a primary oocyte that has not yet completed its first meiotic division.

C. a primary oocyte: The primary oocyte is arrested in prophase 1 from before birth until just before ovulation. The LH surge triggers the completion of meiosis 1, transforming the primary oocyte into a secondary oocyte. Therefore, the cell released during ovulation has already progressed past the primary stage.

D. a primary follicle: This is an early stage of follicular development consisting of a primary oocyte surrounded by one or more layers of cuboidal granulosa cells. It is far from the stage of maturity required for ovulation. Many primary follicles exist in the ovary but only one typically matures monthly.

E. a secondary oocyte: Upon the LH surge, the primary oocyte completes its first meiotic division to become a secondary oocyte and a first polar body. This is the specific cell stage that is released from the ovary during ovulation. It remains arrested in metaphase 2 until fertilization occurs.