Organ systems are made up of tissues which are made up of cells.
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This is referred to as: spontaneous recovery
Spontaneous recovery is a theory of learning and memory which involves unexpected and recurrence of a conditioned response after a period of reduced response or delay. Spontaneous recovery is associated with classical conditioning and operant conditioning. Extinction will happen quickly after a spontaneous recovery, if the conditioned and unconditioned stimulus is not connected.
He observed 15 different finch species that originated as one ancestral bird. all differing in body shape, beak size, and mating habbits
An organism that obtains energy and nutrients by feeding on other organisms or their remains. A food web is a model of the feeding relationships between many different consumers and producers in an ecosystem. Without plants (the primary producers) consumers and decomposers would not be able to live. Producers always start every food chain. A consumer, also called a heterotroph, is an organism that cannot make its own food. It must eat producers or other organisms for energy.