Question

which of the following traits is shared by birds and reptiles but not by any other group in the cladogram? a) vertebrae b) four limbs c) egg shells d) hair/fur

Explanation:

• Option A: Vertebrae is a trait shared by all groups (fish, amphibians, reptiles, birds, rodents, primates) in the cladogram, so it's not unique to birds and reptiles.
• Option B: Four limbs are shared by amphibians, reptiles, birds, rodents, and primates (fish don't have four limbs, but multiple groups beyond birds and reptiles have this trait).
• Option C: Egg shells are a trait connected to both reptiles and birds in the cladogram, and no other group (like fish, amphibians, rodents, primates) is shown to have this trait.
• Option D: Hair/fur is a trait of rodents and primates, not birds or reptiles.

Answer:

C) Egg shells