Single celled eukaryotes are considered some of the most complex cells on earth. Why would scientists believe that single celled
organisms(eukaryotes) are more complex than multi celled
organisms?

Eukaryotic cells are more complex than prokaryotes, and the DNA is linear and found within a nucleus. Eukaryotic cells boast their own personal "power plants", called mitochondria.The complex eukaryotic cell ushered in a whole new era for life on Earth, because these cells evolved into multicellular organisms.

Explanation:

The ability to maintain different environments inside a single cell allows eukaryotic cells to carry out complex metabolic reactions that prokaryotes cannot. In fact, it's a big part of the reason why eukaryotic cells can grow to be many times larger than prokaryotic ones.

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One theory that may explain how eukaryotes became so complex is the endosymbiotic theory. This theory proposes that organelles like mitochondria and chloroplasts were once free-living prokaryotic cells that began to live within a larger host cell.

c. movement because i took the test and it lets me review my answers

the answer is d.) homologous; have mammary glands