Sea urchin spines, snail shells, and rosebush thorns illustrate which predator avoidance strategy?

• A. Mechanical defense
• B. Camouflage
• C. Mimicry
• D. Chemical defense

Answer: (A)

Physical barriers that deter predators are a mechanical defense. Sea urchin spines, snail shells, and rosebush thorns are hard, physical obstacles that make predation costly or painful, discouraging predators from attacking. They rely on structure and toughness rather than hiding (camouflage), imitating another organism (mimicry), or releasing toxins or tastes (chemical defense). So, these examples illustrate a mechanical defense.