<span>An eon is a geologically around tens of millions of years. A period is a million year included in an eon which is also made up of several eras. Therefore my answer is a period due to it being a subset of an era which is a subset of an eon.</span>
In fact, since the Moon is constantly rotating on it's own axis, there is no area of the planetoid which is permanent darkness, and the far side of the Moon is only completely devoid of sunlight during a Full Moon - when the Sun is facing the Moon with the Earth in between.
The correct answer is - biosphere conditions.
The ecosystems and the structure of the vegetation are parts of the wider term that is the biosphere. According to that, any changes that will appear in the functioning of the ecosystems, or if the structure of the vegetation is affected by something, it means that the biosphere is experiencing changes, thus it is becoming affected by this changes.
Once energy is produced in the core of the Sun, it needs a way to travel from the solar center to the outer regions. ... In the radiation zone of the Sun the temperature is a little cooler than the core and as a result some atoms are able to remain intact.