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.
The carbon cycle describes the way the element carbon moves between the Earth's biosphere, hydrosphere, atmosphere, and geosphere. It is important for a few reasons: Carbon is an essential element for all life, so understanding how it moves helps us to understand biological processes and factors that influence them.
Source: Google
Hope this helps you :)
Answer:
The picture is just a black screen so I can’t see the question
GLUCOSE IS CONVERTED INTO CELLULOSE FOR MAKING CELL WALLS. GLUCOSE IS COMBINED WITH NITRATES (COLLECTED FROM THE SOIL) TO MAKE AMINO ACIDS, WHICH ARE THEN MADE INTO PROTEINS. GLUCOSE IS TURNED INTO LIPIDS FOR STORING IN SEEDS.
Answer:
Ostia are tiny pores present all over the body of sponges. its function is to let the water, along with desire nutrient flows interior of the sponges.
