Answer:
Oxygen was not present on early earth
Answer:
For this receptor, the stimulus begins with an explosion of action potentials.
that would be the correct option.
Explanation:
A tonic receptor is one that is activated when the action potentials were maintained over time and during the signaling of the receptor.
Tone receptors require continuous stimulation over a period of time to trigger a response and deliver it to the central nervous system.
It keeps the nervous system constantly active in the environment that surrounds it.
They are slowly adaptable, an example of these receptors are the merkel and ruffini receptors.
The organisms show slowed growth during the winter.
Answer:
The history of the human evolution can be studied by the fossil and DNA evidence. The similarities and advancement in certain characters has revealed the human evolution.
Different evidences like change in the diet, locomotion, brain size, walking ability as compared with the present species and species appeared 6 million years ago. The human genetics evidence and different paintings explain the culture of earlier homo species.The H. sapiens species has highly advance character that help them to survive than any other hominid species. The neanderthals extinction might occur due to their aggressive behavior, low social ability and their large cranial size.
Answer:
C. Disruptive Selection
Explanation:
Disruptive selection occurs when two extremes of continuous variation are favored more than intermediate traits.
The extremes of continuous variation exhibited in this species of snail is the color of their shell which allows them to blend with the background of their habitat.
The shady forest of the habitat makes the dark-shelled individuals to be better hidden from bird predators, while the light-shelled individuals are better hidden in well-lit brushy edge areas. This disruptive coloration exhibited by both individuals makes both individuals of this species of snail less vulnerable to predation.
Both individuals of this species both extremities would naturally survive in this habitat as snails with intermediate extremities would be highly preyed on since there is no area of intermediate brightness in the habitat to make them invisible to predators
