For question 12:
Cats and dogs, both mammals, could be classified as distinct animals based on their physical characteristics. Cats typically have retractable claws, while dogs do not. Cats also have a more flexible spine compared to dogs.
For question 13:
Having an exoskeleton, like snails and beetles, provides protection from predators and environmental factors. However, it can limit growth and movement due to the rigidity of the exoskeleton.
For question 14:
Reptiles and mammals are both vertebrates, but reptiles typically have scales and lay eggs, while mammals have fur or hair and give birth to live young. Reptiles are cold-blooded, while mammals are warm-blooded and produce milk for their young.