Gills and Gaseous exchange

Which organs of a bony fish allow oxygen to be exchanged between the fish’s blood and the surroundings?

• Lungs

• Gills

• Fins

• Trachea

Which of the following is a defining aspect of the countercurrent exchange principle?

• The blood in the capillaries of the lamellae flows in the same direction as the water passing over the lamellae

• The oxygenated and deoxygenated blood in the capillaries of the lamellae mix and flow in the same direction

• The blood in the capillaries of the lamellae flows in the opposite direction to the water passing over the lamellae

What is the primary purpose of the countercurrent exchange system in fish?

• To streamline the gills and enable efficient swimming

• To increase the surface area of the gills

• To maintain a high oxygen concentration gradient

• To remove waste products, like urea

• To Shorten the diffusion pathway

Which of the following Graphs correctly demonstrates the countercurrent flow of water and blood in fish gills?

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The diagam shows a simplified outline of fish' respiratory system.

Which of the following structures are indicated by X?

• Spiracles

• Alveoli

• Gill Tracheoles

• Gill Filaments

The diagram shows a close-up view of a stack of gill filaments.

which of the following structures are indicate by X

• Tracheoles

• Bronchi

• Alveoli

• Spiracles

• Lamellae

Which of the following correctly describes the general structure of fish gills?

• The gill lamellae are long tubes that connect to the surface of the body which directly supply the tissues with oxygenated water

• The gill filaments are arranged in stacks, and each gill filament has multiple gill lamellae projected from its surface

• The gill filaments are arranged in long tubes which branch off into gill lamellae that supply the tissues with blood

• The gill lamellae are arranged in layers, and each gill lamella has multiple gill filament projected from its surface

The graph compares gill surface area and body weight for various different species of fish (indicated by different circles).

what is the trend shown?

Suggest why we see this trend.

• As body mass increases, the surface area of the gill increases

• As body mass increases, the surface area of the gill decreases

• As body mass increases, there is no significant change in the surface area of the gills

• The surface area of the gills has no relation to body mass, as this is determined by nutrition and available space

• A larger body mass requires more gas exchange to take place to provide all the cells with the required oxygen