Aves are warm-blooded animals and have a ______ heart.

four-chambered

The correct answer is Option (1) - four-chambered

Aves (birds) are warm-blooded animals and have a four-chambered heart.

Four-chambered heart:

• Birds, like mammals, have a four-chambered heart, which consists of two atria and two ventricles.
• The four-chambered heart allows for efficient separation of oxygenated and deoxygenated blood, providing birds with the high metabolic rate and energy demands required for flight.
• This adaptation is crucial for maintaining a constant and elevated body temperature, characteristic of warm-blooded or endothermic animals.