Question

The longest loop of Henle is found in

• A. Opossum
• B. Porcupine
• C. Kangaroo rat
• D. Rhesus monkey

Answer 1

The correct option is C

Kangaroo rat

The correct option is C.
Explanations for the correct option:

1. The loop of Henle is a U-shaped tubule in the nephron that conducts urine and aids in the reabsorption of water and sodium ions.
2. Kangaroo rats are nocturnal rodents found in the north and central America.
3. They consume dry food and don't have a high water intake. Thus their kidneys are well organized to produce only small amounts of highly concentrated urine.
4. They have long loops of Henle that enable efficient water absorption.

Explanations for the incorrect options:
Option A:

1. Opossums are small marsupials found in Mexico that are non-aggressive.
2. They belong to the Didelphimorphia order and possess a pouch to carry their young ones.

Option B:

1. Porcupines are rodents that contain sharp spines on their coat that helps shield them from predators.
2. They belong to the rodent family and are found in Italy, Asia, and Africa.

Option D:

1. Rhesus monkeys are well-known macaque that is mainly herbivorous.
2. They belong to Cercopithecidae family and are highly similar to humans.

Final answer: The longest loop of Henle is found in option (C) Kangaroo rats.