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 mid Atlantic rift is in the middle of the Atlantic Ocean where 2 plates diverge. That means that the 2 plates are moving away from each other, and the mantles lava is filling the gap between the two plates. The newest land is located closest to the ridge, and the oldest land is located farther away from the ridge.
PLEASE MARK BRAINLIEST!!! Thanks!!
Answer:
This is what I put (its kinda bad so don't judge)
Explanation:
A) Examining Table 1 with cancerous cells and HeLa cells we can see that with both HeLa and cancerous cells when treated with EGF increase in cells. Examining Table 2 we can see that HeLa cells create the most cells when treated with a concentration of 25 ug of EGF.
B) Normal cells increased by 33 when treated with a concentration of 10 ug of EGF. Cancerous cells increased by 405 when treated with a concentration of 10 ug of EGF. We can conclude from this that the cancerous cells multiply faster than normal cells with a concentration of 10 ug of EGF.
C) The mitotic index of HeLa cells with zero EGF treatment is 11 mitotic figures noted per 73 high power fields. The mitotic index of HeLa cells with 10 ug of EGF treatment is 8 mitotic figures noted per 90 high power fields. The mitotic index of cancerous cells with zero EGF treatment is 22 mitotic figures noted per 60 high power fields. The mitotic index of cancerous cells with 10 ug of EGF treatment is 27 mitotic figures noted per 465high power fields.
I'm on D right now so I'll put that in when I'm done with it
Answer:
DNA is present in chromosomes
