Biology · Unity and diversity
A2.1 — Origins of cells
Biology · SL / HL · syllabus-mapped notes
A2.1.1
Conditions on early Earth and the pre-biotic formation of carbon compounds
Describe conditions on early Earth, and explain how they allowed carbon compounds to form spontaneously.
A2.1.2
Cells as the smallest units of self-sustaining life
Discuss what separates living from non-living, why the cell is the smallest self-sustaining unit, and why viruses are not living.
A2.1.3
Challenge of explaining the spontaneous origin of cells
Explain why the spontaneous origin of cells is hard to account for, and name the four developments it required.
A2.1.4
Evidence for the origin of carbon compounds
Evaluate the Miller–Urey experiment as evidence for the origin of carbon compounds.
A2.1.5
Spontaneous formation of vesicles by coalescence of fatty acids into spherical bilayers
Explain how fatty acids spontaneously form spherical bilayers, and why an enclosed compartment matters.
A2.1.6
RNA as a presumed first genetic material
Explain why RNA is presumed to have been the first genetic material.
A2.1.7
Evidence for a last universal common ancestor
Give the evidence for a last universal common ancestor.
A2.1.8
Approaches used to estimate dates of the first living cells and the last universal common ancestor
Outline how the dates of the first cells and of LUCA are estimated.
A2.1.9
Evidence for the evolution of the last universal common ancestor in the vicinity of hydrothermal vents
Give the evidence that LUCA evolved near hydrothermal vents.