endosymbiosis and origin of eukaryotes

endosymbiosis and origin of eukaryotes - Sarah Ahmed...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Sarah Ahmed Biology 110 Extra Credit Report 11 April 2009 Endosymbiosis and the Origin of Eukaryotes Two different types of organisms are prokaryotes and eukaryotes. The oldest eukaryotic fossils that we have found are 1.5 billion years ago. The oldest microfossils, though, are 3.5 million years old. This shows that eukaryotes were not the first organisms on earth. Prokaryotic fossils are older than eukaryotic fossils. They showed up at least one billion years before eukaryotes (Raven 70). The structure of prokaryotes is very simple compared to eukaryotes. The main difference between the two is that prokaryotes do not have a nucleus and eukaryotes do. Prokaryotes are very simple. They “are small, consisting of cytoplasm surrounded by a plasma membrane and encased within a rigid cell wall, with no distinct interior compartments” (Raven 84). Eukaryotes are not as simple as prokaryotes. They “are far more complex than prokaryotic cells” (Raven 85). Eukaryotic cells have an actual nucleus to hold the genetic information. They also have many organelles. Two of the many organelles in eukaryotic cells have their own DNA. One is the mitochondria and the second, which is in only plants, is the chloroplast. These two organelles are bounded by two membranes. Most organelles divide when the cell it is in
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
divides. The mitochondrion is different from most organelles from this aspect as well. It
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 4

endosymbiosis and origin of eukaryotes - Sarah Ahmed...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online