[Campbell Biology P.788] Which of the following is NOT described as a weight-saving modifica... | Practice Question

Which of the following is NOT described as a weight-saving modification or physiological adaptation primarily for flight efficiency in birds, according to the provided text?

  • A: Females having only one ovary.
  • B: Lack of a urinary bladder.
  • C: Being toothless.
  • D: Having a four-chambered heart.

Explanation

While a four-chambered heart is crucial for the high metabolic rate required for flight, the text describes it as supporting oxygen and nutrient supply and high metabolism, not as a weight-saving modification. The other options single ovary, lack of urinary bladder, being toothless are explicitly mentioned as adaptations for reducing weight.