Q: What do many mollusks secrete for their protection? Choices: - mucus - sedimentation shell - microscopic shell - calcareous shell A:
calcareous shell

Q: Birds evolved from what type of ancestor? Choices: - apes - insect - fish - reptile A:
reptile

Q: Most enzymes are classified as what? Choices: - lipids - acids - hormones - proteins A:
proteins