The Precambrian era envelopes the major bulk of the history of the Earth, beginning from the creation of the planet approx 4.5 billion years ago and terminating with the origination of composite, multicelled forms of life approximately 4 billion years after.
The Precambrian refers to the earliest of the geologic ages that are signified by the distinct layers of sedimentary rock. The Earth was about more than six hundred million years old when life started. The planet had cooled down from its native molten state, creating a solid crust and oceans formed by water vapor in the atmosphere.
At about three billion years ago, the atmosphere of the Earth was virtually devoid of oxygen. At approximately 2.4 billion years ago, oxygen was discharged from the seas as a waste product of photosynthesis by cyanobacteria. The levels of the gas slowly raised, attaining about 1 percent around two billion years ago.
Approximately 800 million years ago, the levels of oxygen attained about 21 percent and started to breathe life into more composite species. The oxygen-rich ozone layer was also created, protecting the surface of the Earth from the harmful solar radiation.
True rib : the first seven ribs attach to the sternum (the breast bone) in the front and are known as true ribs (or sternal ribs)
False ribs: the lower five ribs do not directly connect to the sternum and are known as false ribs
Floating ribs :The floating ribs are less stable and risk breaking because they have only one attachment
Dorsally to the vertebrae and have very thin bone tissue locked in muscle as they extend
Laterally.
I think the answer would beeeeeeeeee!!!!!!! May be autotrophs is the answer hope I helped
I'm not 100% sure which biology class you are in are you doing the moth activity? If so then I would believe that the light moth would be easier to see on a dark tree trunk