How long will it take three quarters of a sample of a radioactive element to decay if its half-life is 4 days?
a. 2 days
b. 3 days
c. 4 days
d. 8 days
5
Another word for variation is
a. similarity
b. difference
c. adaptation
d. mutation

Directions: read the descriptions of the four islands presented in the lesson. 1. list two new traits that each new species of rat might demonstrate as it adapts to the conditions on each island. 2. introduce one of the four new rat species to another island and describe one challenge it would encounter and one success as it adapts to its new environment.