<h3><u>Answer;</u></h3>
d. a neuron recharges before it can fire again.
<h3><u>Explanation;</u></h3>
- <em><u>Refractory periods are a short phase in time following an action potential where another action potential cannot be generated. </u></em>
- <em><u>It is the period immediately following the transmission of an impulse in nerve or muscle, in which a neuron or muscle cell regains its ability to transmit another impulse. </u></em>
- There are two types of refractory period, that is the absolute refractory period and the relative refractory period. Absolute refractory period is the first part of a refractory period during which, the neuron will not fire again no matter how great the stimulation and this only lasts for a short time.
- Relative refractory period occurs when a stronger than usual stimulus is required to trigger the action potential before the neuron returns to resting state.
Answer:
NOAA scientists primarily use sonar to develop nautical charts, locate underwater hazards to navigation, search for and map objects on the seafloor such as shipwrecks, and map the seafloor itself.
This type of fossil is called a mold. A cast fossil forms when a mold
fossil is filled with some form of mineral, usually through the seepage
of water depositing the minerals within the mold. In time, the mold is
filled and the materials deposited harden, creating a replica of the
original fossil.
Hope this helps you :p
Homeostasis, my friend.
Homeostasis is the process of maintaining a constant internal environment (temperature, water content, available energy, available oxygen & concentration of wastes in the blood.) Some animals are able to do this and are called endothermic or 'warm-blooded' (like humans). However, not all animals are able to do all of this - and they are referred to as ectothermic or 'cold-blooded.'
Animals need to be able to maintain a stable internal environment because if they do not, they will most likely die. Animals need warmth to survive, so they need to be able to have a constant body temperature whether it be by using their body to create warmth or having to sit in the sun to keep warm,
Hope this helps.