Answer:
it cannot be easily degraded in our environment.Like humans, animals and plants are exposed to PBTs in the environment through air, water and food. ... Persistent bioaccumulative toxic substances (PBTs) are chemicals that do not degrade easily in the environment.
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.
Rigid skeletons are formed from materials including chitin (in arthropods), calcium compounds such as calcium carbonate (in stony corals and mollusks) and silicate (for diatoms and radiolarians).
The vinegar is a charged molecule, whereas, the oil is neutral. As like dissolves like, the vinegar can be dissolved with charged molecules and the oil can be dissolved with neutrals. So, to mix vinegar and oil shaking is required.
In case, the person does not mix oil and vinegar dressing before pouring this on the salad, it would not produce a good taste, as the content of vinegar and the oil would not be appropriate.
