Which Statement Concerning the Countercurrent System Is INCORRECT

question 258

Multiple Choice

Which statement concerning the countercurrent system is INCORRECT?

• A) The loops of Henle of juxtamedullary nephrons are responsible for establishing a vertical osmotic gradient in the interstitial fluid of the renal medulla by countercurrent multiplication.
• B) The active NaCl pump of the ascending limb of Henle's limb can establish a 1,200 mosm/litre concentration difference between the ascending and descending limbs at any given horizontal level.
• C) By means of countercurrent exchange, the vasa recta preserve the vertical osmotic gradient while supplying blood to the medullary tissue.
• D) The collecting tubules of all nephrons utilize the driving force of the vertical osmotic gradient to accomplish variable H₂O reabsorption under the control of vasopressin, which governs their permeability.

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Definitions:

Cladogenesis

A process in evolutionary biology where a species splits into two distinct species, rather than evolving as a single lineage, leading to increased biodiversity.

Y Chromosome

A sex chromosome found in males that carries genes involved in sex determination and other biological functions related to male development.

Genetic Information

Data regarding an organism's genes, their functions, and their influence on physical and behavioral characteristics, derived from DNA analysis.

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Groups of organisms that are selected and mated to perpetuate certain genetic traits or to increase the genetic diversity of offspring.