<span> A scientific law always applies under the same conditions, and implies that there is a causal relationship involving its elements.</span>
an organism is resistant to a chemical if it has a gene that protects it from the chemical.
Common mistakes and misconceptions
Natural selection is a mechanism, or cause, of evolution. Adaptations are physical or behavioral traits that make an organism better suited to its environment. Heritable variation comes from random mutations. Random mutations are the initial cause of new heritable traits.
Meristems are cell divisions. Trees grow by the cell divisions
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