Which technology are environmental scientists using to photograph poaching activities in africa? a. unmanned aerial systems (uas) b. gel electrophoresis c. environmental dna (edna) surveillance d. acoustics

Option A. Unmanned aerial systems (UAS)

Explanation:

Unmanned aerial systems are cheap method of monitoring an area with radius of thousands of acres/km.  

These systems work by using infrared light which are able to capture images and videos in night also.  

Due to this, UAS  is now being used an essential equipment in anti-poaching missions where it assists in doing Bird’s nest surveys, tracking activities of animals, automated species identification etc.  

 Being cheaper makes it financially suitable for African countries.

Thus, option A is correct.

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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volcanoes (an event in the geosphere) release a large amount of particulate matter into the atmosphere. these particles serve as nuclei for the formation of water droplets (hydrosphere). rainfall (hydrosphere) often increases following an eruption, stimulating plant growth (biosphere).