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.
The greatest issue facing
society that results from the development of new applications of cell
technology is that it can make the arteries narrower especially for patients
with heart diseases. Although cell technology has been revealed as an ideal
cure for heart related diseases.