Which one of the following is present today but was absent about 4.6 billion years ago?
Which one of the following is present today but was absent about 4.6 billion years ago?
The correct option is B Oxygen
It is believed that the planet earth came into existence about 4.6 billion years ago. The earth existed without life on it for nearly 750 million years. The air was devoid of oxygen, and all that existed was molten lava flowing into the oceans. There were other chemicals in the air though, and these were supposedly washed down by rains into the ocean, and converted into a so-called organic “soup”. It was from here that life originated in a series of small steps. Simple organic molecules gradually joined together and served as building blocks of complex organic molecules such as nucleotides (DNA/RNA). These nucleotides self-replicated and have progressively led to the various life forms that we see today.
It is believed that the planet earth came into existence about 4.6 billion years ago. The earth existed without life on it for nearly 750 million years. The air was devoid of oxygen, and all that existed was molten lava flowing into the oceans. There were other chemicals in the air though, and these were supposedly washed down by rains into the ocean, and converted into a so-called organic “soup”. It was from here that life originated in a series of small steps. Simple organic molecules gradually joined together and served as building blocks of complex organic molecules such as nucleotides (DNA/RNA). These nucleotides self-replicated and have progressively led to the various life forms that we see today.
