Es orcas, or killer whales, are natural predators of sea otters. it has been observed that in regions where the sea otters are not
present, sea urchins grow rapidly and destroy much of the natural kelp vegetation
which of these statements is correct in this context?
kelp is the keystone species because their survival is key to the survival of
the entire ecosystem.
sea otters cannot be considered the keystone species because they are not
the top predators in the ecosystem.
sea urchins are the keystone species because they multiply rapidly in the
absence of their natural predators,
sea otters are a keystone species as they prevent a herbivorous species
from completely destroying a plant species.
submit
interdependence of organisms

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.  

read more on -

the denominator has a very specific role.

as the gila monster consumes the eggs or young of the desert cottontail and gambel's quail, thus its main food supply is only accessible for a restricted time duration every year. however, for this, the gila monsters exhibit three adaptations, which elevate their survival rate in the desert condition.  

first, is that they possess huge bodies, and can consume greater concentrations of food during a small period. secondly, they require to feed infrequently as they can accumulate fat in their tails. ultimately, their rate of metabolism is very low, so that they can burn their reservoirs of fat gradually.