Q13 - Glomerulus Size and Habitat Shape Kidney Concentrating Power
In kidneys, glomeruli are sieves which filter plasma into nephrons. Nephrons modify this fluid, and reabsorb or excrete it. The volumes of individual glomeruli, leading to two types of nephron, were measured in different animals. In all species, juxtamedullary nephrons are much fewer in number than cortical nephrons, but produce more concentrated urine.
Using the information and data, determine which of the statements are true or which are false.
A. Glomerular volume is proportional to body size.
B. Bush Babies (Galagidae) live in arid habitats.
C. Jerboa (Dipodidae) and Bush baby nephron volume distribution has evolved convergently (not inherited from a common ancestor).
D. In rats (Rattus), the majority of urine is derived from juxtamedullary nephrons.
Question reproduced from IBO 2017, Theoretical Exam B, licensed under CC BY-NC-SA 4.0 - attributed to the International Biology Olympiad. Open the full exam PDF · Official answer key & worked solutions