4. To be considered a fossil an
organism must have lived only during a short
part of Earth's history; many fossils of the
organism must be found in rock layers; the
fossil must be found over a wide area of
Earth; the organism must be unique.

mendel's first law states that during the formation of reproductive cells , pairs of hereditary factors for a specific trait separate so that offspring receive one factor from each parent.

explanation:

the relative standard reduction potential of the half-cell in which reduction occurs; more positive than the other half-cell. reduction is a chemical process in which electrons are added to an atom or an ion; it always occurs accompanied by oxidation of the reducing agent.