Zusammenfassung der Ressource
The Origin of Cells
- Cell division and the origin of cells
- can only form by division
of pre-existing cells
- all cells in our body came from a zygote
- the zygote formed through the fusion a sperm and egg cell
- our parents can be traced back to their zygotes
- this traces back millions of years and shows our origins
- cell artificially developed in 2010
- original theory was spontaneous generation
- disproved by Louis Pasteur
- Origin of the first cells
- must have arisen from non-living material
- theories
- production of carbon compounds
- assembly of carbon compounds into polymers
- Development of a mechanism for inheritance
- Membrane formation
- Endosymbiosis and eukaryotic cells
- creation of eukaryotic cells
explained by endosymbiotic theory
- mitochodria - free living prokaryotic organisms
- mit. developed aerobic processes
- Larger anaerobic prokaryotes took them in by endocytosis
- allowed them to live in cytoplasm
- evolved to today's eukaryotic cells
- prok. features of mit. and chloroplasts
- circular molecule with genes
- prok. like 70S ribosomes
- transcribe own DNA
- use mRNA to synthesize own proteins
- only can be produced by division of pre-existing
- two prokaryotes in symbiotic relationship
- mutualistic
- food for mit.
- energy for large prok.
- natural selection
- also applies to chloroplasts