Blood plasma osmolarity is higher than intracellular fluid osmolarity.

A. Uterine tube: Fertilization typically occurs in the uterine tube (also known as the fallopian tube). The sperm travels from the cervix through the uterus and into the uterine tube, where it meets and fertilizes the egg.

B. Uterus: The uterus is where the fertilized egg implants and develops into a fetus, but it is not where fertilization occurs.

C. Ovary: The ovary is where eggs are produced and released during ovulation, but fertilization does not occur here.

D. Urinary bladder: The urinary bladder is part of the urinary system, not the reproductive system, and has no role in fertilization.

A. Ca2+: prevents the entrance of any more sperm- While calcium ions play a role in the slow block to polyspermy, the fast block involves sodium ions.

B. Na+: prevents the entrance of more Na- The fast block to polyspermy involves sodium ions (Na+), but the depolarization of the egg membrane prevents the entrance of more sperm, not just more Na+.

C. Na+: prevents the entrance of Ca2+. The fast block prevents additional sperm from entering, not calcium ions.

D. Na+: prevents the entrance of any more sperm: The fast block to polyspermy involves the opening of sodium ion channels, leading to depolarization of the egg membrane. This depolarization prevents other sperm from binding to and penetrating the egg.