Which best describes the relationship of the embryo and the fetus?
o
o
o
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the embryo and the fetus are both formed when the sperm and egg fuse.
the fetus differentiates into the embryo and the placenta.
the embryo has more cells than the fetus has.
the fetus is more developed than the embryo.

If scientists are wrong about earth's age based on radioactive material and the decay rates are really much faster, how would nuclear power plants be affected?

In the practice of science, this type of reasoning is used to develop explanations.

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.