The title must be self-explanatory, meaning that a casual reader can find out what you did without having to go through the paper. Hence, titles such as "A Biology 109 Lab Report" or "The Pine Lab" really are useless. The title should indicate the following three things:
1. The factor that was manipulated.
2. The parameter that was measured.
3. The organism that was used, preferably identified by genus and species.
For instance, a title such as "The effect of temperature on the rate of heartbeat in Xenopus laevis tadpoles" fulfills the three criteria above because it specifies the factor manipulated (temperature), the parameter measured (heartbeat rate), and the organism (Xenopus laevis) used.