D I believe, in the picture that is attached explains
Answer:
Due to presence at early days of the planet.
Explanation:
We only find the remains of single celled organisms in the oldest fossils because the single celled organisms are the organisms that were present in the early days of this planet. These single celled microbes were present about 3.7 billion years ago while on the other hand, the oldest rocks are only a little older i. e. 3.8 billion years so these single celled organisms are considered as oldest fossils on this planet.
Answer:B there were soon be insufficient food for the growing human populatio
I suggest you watch the Amoeba Sisters video again, 1-2x and take notes.
Biomagnification is when toxins / heavy metal are present in small amounts in fish, but accumulate as you move into higher trophic levels. This is one reason why it can be toxic for humans to eat tertiary or quaternary consumers, such as swordfish, shark, etc.
