Question

The era called 'age of prokaryotic microbes' is
A)Archaeozoic
B)Precambrian
C)Phanerozoic
D)Proterozoic

Answer 1

Hint: Prokaryotes need mitochondria or some other eukaryotic layer bound organelles; and it was once believed that prokaryotes needed cell compartments, and along these lines, all cell parts inside the cytoplasm were unenclosed, aside from an external cell film.

Complete answer:
The term Proterozoic comes from the Greek words Proteros (meaning first) and Zoon (meaning life). Although the earliest fossils are believed to be found in older Archean rocks, the oldest evidence of life from the Proterozoic stratum has been known for many years. The Proterozoic is the last phase of the so-called Precambrian Period, 3.7 billion years before the Paleozoic. Many of these life forms have developed photosynthetic abilities. As a byproduct of photosynthesis, they create oxygen, and over billions of years’ oxygen changes the Earth's atmosphere. Because oxygen is poisonous to some early life forms, many of them will be lost. Others thrive and thrive in the first multicellular organisms to be preserved as the ediacaran fauna.

The beginning and end of the Proterozoic were characterized by extensive glaciation. About a billion years ago, the dominant organisms on earth were cyanobacteria and protozoa, which is why it was known as the Proterozoic. The proterozoic is known as the age of prokaryotic microbes. Microbes were not dominant during the Archaeozoic, Precambrian, and phanerozoic Eras. Therefore, they are not referred to as prokaryotic microbes.

Hence, the correct answer is option (D)

Note: A prokaryotic cell can have a cell wall, but it is not made of cellulose. These cells may have extra DNA in structures called plasmids. Prokaryotic cells are small (the average bacterial cell is about 8 microns long).