Unit 6 discussion PDF

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Introduction to Biology...

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Introduction Lumen learning (n.d) categorised all living things into Archea, bacteria and Eukayra. The first and second categories are considered to be prokaryortic cells as they don’t have nucleus (Lumen Learning, n.d). The third group which consist of all the eukaryotes have the nucleus Lumen Learning (n.d) confirms that among the three group, bacteria appears to be the earliest, this is due to the fossils that vividly support the hypothesis. By comparing the fossils, biologist has established that all eukaryotes have single common ancestors (Learning, n.d). Libretexts (2020) suggested that fossil records and genetic evidence entails that prokaryotic cells were the first organisms on earth Endosymbiosis and the Evolution of Eukaryotes One of the major themes of the origin of Eukaryotes is the symbiosis relationships known as endosymbiosis (Libretext, 2020). According to Lumen Learning (n.d), endosymbiosis is a symbiotic relationship that states that eukaryotes are a product one prokaryotic cell engulfing another. Both the engulfing and engulfed prokaryotes survived and that there was a mutual benefit between them over time until the cells were not recognisable over time (Lumen Learning, n.d). A microscopic observation taken in 1800s supports this hypothesis that when the cell was put under a microscope, it showed the mitochondria moving around in the cells like worms. This suggested to the early biologist that the moving mitochondria were probably bacteria living inside the host cell (Lumen Learning, n.d). Libretext (2020) highlights that through endosymbiosis, aerobic bacteria and photosynthetic bacteria were consumed and evolved to mitochondria and chloroplast respectively.

Reference Libretexts. (2020, August 15). 13.2:Eukaryotic Origins. Biology LibreTexts. Retrieved December 21, 2020 from https://bio.libretexts.org/bookshelves/introductory_and_General_Biology/book %3A_Concepts_in_Biology_(Openstax)/13%3A_Diversity_of_Microbes_ung_and_p rotista/13.2%3A_eukaryotic-origns/

Lumen Learning. (n.d.). Eukaryotic Origins | Bio 101 https://courses.lumenlearning.com/bccbio101/chapter/eukaryotic-origin/...