| A | B |
|---|
| cell | smallest living unit of an organism |
| vertebrate | cat |
| invertebrate | worm |
| spine | backbone |
| warm blooded | constant body temperature |
| cold blooded | temperature depends on temperature of the environment |
| control | standard for what you observe |
| test set up | one different factor |
| stromatolites | oldest evidence of life on earth |
| fossils | remains of organisms from the past |
| paleontologists | person that studies/hunts for fossils |
| extinct | gone forever |
| genes | sequence of chemicals in organism's cells |
| mutations | change in genes that can be passed on |
| traits | characteristics of organisms |
| natural selection | best-fit organism survives and reproduces |
| artifical selection | breeding organisms to get desirable traits |
| micro-organism | so small you need a microscope to see it |
