The answer to your question is A.) Charles Darwin
Answer:they won't for a pair
Explanation:Basically it all depends on process called complementary base pairing, the structure of thymine and adenine is such that it forms two hydrogen bonds and therefore pair up
2.guanine and cytosine have such structure that they form three hydrogen bonds and pair up
So Adenine complements only thymine and guanine complements cytosine and there aren't any chances of guanine pairing up with thymine.
I think it would be Carbohydrates.
I think the answer would be B but that could be wrong. I hope this helped!!
Answer:
The appearance of free oxygen in the Earth's atmosphere led to the Great Oxidation Event. This was triggered by cyanobacteria producing oxygen which developed into multicellular forms as early as 2.3 billion years ago
Explanation:
To clarify what I said here are some questions to help!
How did oxygen first appear?
Whiffs in the air is how oxygen first appeared billions of years ago.
For the most part, scientists agree that oxygen, though lacking in the atmosphere, was likely brewing in the oceans as a byproduct of cyanobacterial photosynthesis as early as 3 billion years ago
When was oxygen found?
2.33 billion years ago
Since its first appearance 2.33 billion years ago, oxygen accumulated in high enough concentrations to have a weathering effect on rocks just 10 million years later.
I don't know if this helped you but if it does, please let me know!