3.1 Early life and Classification of Prokaryotes

components of cell theory

cells are fundamental units of life, all living organisms are composed of cells, all cells come from pre-existing cells and modern cells evolved from a common ancestor (recently added)

why is cell size limited by Surface Area Volume Ratio

Cell size is limited by the surface area-to-volume ratio because as a cell grows, its volume increases faster than its surface area. This limits the ability of the cell to transport nutrients and waste efficiently.

2 types of microscopes

light microscopes - poorer resolution and can view living cells

electron microscopes - higher resolution but can only view dead cells bc they must be prepared in a vacuum

3 domains of life

bacteria, archaea, eukarya

bacteria and arch - are are both prokaryotic

Eukaryotes have membrane-enclosed compartments (organelles) including nucleus where cells’ DNA is

How is archaea different to bacteria

half their genes are unique compared to bacteria, no peptidoglycan, archaean lipids are linked by ether bonds and not ester bonds. Has 2 biological processes (translation and transcription) more similar to eukaryotes and doesn’t reproduce resting spores. Also often thrives in extreme environments and have unique ribosomal RNA sequences compared to bacteria.

Describe cyanobacteria’s role in the “Great Oxygenation Event”. What key feature of our atmosphere was a result of this event?

Earth’s atmosphere had virtually no oxygen and extreme radiation due to no ozone layer. Early Earth Cyanobacteria performed photosynthesis taking carbon dioxide from the atmosphere and released oxygen and glucose = increase in oxygen in the atmosphere until eventually there was enough that an ozone layer to begin to form. Allowed organisms to move from oceans onto land