Regarding various excretory processes and structures, which statements are accurate?
a. Uricotelic animals, like birds and reptiles, excrete nitrogenous waste as a pellet or paste.
b. Protonephridia in Platyhelminthes are primarily for osmoregulation.
c. The functional units of the kidney are called calyces.
d. In cortical nephrons, the loop of Henle extends deep into the medulla.
e. The GFR in a healthy individual is about 180 litres per hour.
f. The counter-current mechanism is facilitated by the special arrangement of Henle’s loop and the peritubular capillaries.
g. Human kidneys can produce urine nearly four times concentrated than the initial filtrate.
