Question

Which of the given characteristics is not found in the mammals?

• A. They have mammary glands.
• B. They have a ventral nerve cord.
  
• C. They have presence of hair or fur.
  
• D. They have four-chambered heart.

Answer 1

The correct option is B They have a ventral nerve cord.

Mammals have the presence of mammary glands, hair or fur, and a four-chambered heart. Mammals are chordates and have a dorsal nerve cord which gives rise to the central nervous system.

The presence of a ventral nerve cord is not a chordate characteristic, so, the correct answer is option B.