Answer:
The last one: dinosaur footprints preserved in mud turned to rock
Fossils have to be physical remains of an animal.
Hope this helps!
Thank you for posting your question here at brainly. Below are the choices. The answer is 4.
1)Cell signaling is observed in single-celled organisms that reproduce asexually through binary fission.
<span>2)The mechanisms of cell signaling are similar in organisms whose last common ancestor lived a billion years ago. </span>
<span>3)The pathways in primitive organisms, such as bacteria, are shorter than in those in advanced organisms, such as humans. </span>
<span>4)Simple forms of life that have not evolved much since the origin of life, such as prokaryotes, use cell signaling.</span>
Prokaryotes are single-celled organisms of the domains Bacteria and Archaea. All prokaryotes have plasma membranes, cytoplasm, ribosomes, a cell wall, DNA, and lack membrane-bound organelles. Many also have polysaccharide capsules. Prokaryotic cells range in diameter from 0.1–5.0 µm.
Like a prokaryotic cell, a eukaryotic cell has a plasma membrane, cytoplasm, and ribosomes, but a eukaryotic cell is typically larger than a prokaryotic cell, has a true nucleus (meaning its DNA is surrounded by a membrane), and has other membrane-bound organelles that allow for compartmentalization of functions. Eukaryotic cells tend to be 10 to 100 times the size of prokaryotic cells.
