Which of the following characteristics is closely associated with mammals and birds but not other groups of animals?
A) They have spinal cords.
B) They have brains.
C) They are endothermic.
D) They are arthropods.
E) They are very plentiful compared to other animal groups.

Question

Quizplus · Accepted Answer

Endothermy (the ability to internally regulate body temperature) is a characteristic that is unique to mammals and birds among animals. Spinal cords and brains are found in many other animal groups, and arthropods are a completely separate and distinct group from mammals and birds. The statement about abundance is not a relevant characteristic to this question.

Which of the Following Characteristics Is Closely Associated with Mammals