

EXAMPLES!
Living organisms can be divided into two main groups,
__(1)__ and animals. Animals can be divided into two main sub-groups. Animals without backbones are called
__(2)__ and those with backbones are called
__(3)__. The vertebrates can be further classified into groups called
__(4)__, whose bodies exist at the temperature of their surroundings, and
__(5)__, which must maintain a particular body temperature.
Which missing word(s) matches space
__(1)__? [7d-26]