Answer :There was enough oxygen in the atmosphere to support a major burst of life on Earth
Explanation:
The Great Oxygen Event marks the time, approximately 2.5 billion years ago, when there was enough oxygen in the atmosphere to support a major burst of life on Earth
For the first half of the Earht's history, there was no oxygen in the atmosphere. It was inhabited only by single-celled organisms.Of those simple life forms, the cyanobacteria may have. evolved a way to take energy from sunlight, and used it to make sugars out of water and carbon dioxide. They used the same chemical process we know as photosynthesis. This released vast quantities of oxygen into the atmosphere and triggered the evolution of complex life.
The correct answer is Galen.
Galen considered anatomy as the foundation of medical knowledge, and he recurrently dichotomized and tested on the lower animals like pigs, sheep, and goats. Galen's supported dissection as the method to better the skills of surgery and research works.
In his work, he illustrated seven pairs of cranial nerves, observed the structural distinctions between the veins and arteries, and illustrated the valves of the heart.
Scientists use fossils to learn about organisms' lives and evolutionary relationships, to understand geological change, and even to locate fossil fuel reserves.
No generations or hybrid would form before meselson and stahl would have observed evidence of a band in the cscl gradient.
The conservative model predicts that, following a single replication, half of the newly formed DNA double helices will be made entirely of the original, or old, DNA, and the other half will be entirely new. Then, each double helix would be completely replicated during the second round of replication. After that, 25% of the double helices would be all new, and 25% would be entirely old. Thus, the fraction of entirely new DNA double helices would increase with each succeeding round of replication, but the total number of completely unique DNA double helices would remain constant. Therefore, no hybrid DNA molecule containing 14N and 15N is replicated in the conservative model.
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<span>B.
exhibit identical biochemical makeup</span><span>B.
exhibit identical biochemical makeup</span><span>B.
exhibit identical biochemical makeup</span>