When examining the fossil record, a large environmental change, like an asteroid hitting the earth and wiping out a number of species, followed by adaptive radiation, would best be described by what kind of model?
a: habitat preference
b: punctuated equilibrium
c: temporal isolation
d: allopolyploidy
e: gradual speciation

The Answer is B: Punctuated Equilibrium

Explanation:

Punctuated equilibrium describes how the process of evolution works and are usually coined from first appearance and subsequent histories and number species available in the fossil record.

/the trachea, commonly known as the windpipe

the answer that best describes the relative refractory period in the neuron is the resting membrane potential is restored, but concentrations of sodium and potassium are not restored to their original state.

the refractory period is the time during which another stimulus given to the neuron will not lead to a second potential. thus, because na+ channels are inactivated during this time, additional depolarizing stimuli do not lead to new action potentials.  

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