Early life Flashcards
1
Q
How long has Life existed?
A
3.5 Billion
2
Q
Describe the diversification of life
A
life has evolved from simple to complex
3
Q
What are the 3 elements of cell theory?
A
- All cells come from pre-existing cells
- All organisms are composed of cells and the products of cells
- Cells are the smallest unit of life
4
Q
Describe the possible roles of RNA and ribozymes in the first simple cell
A
RNA is a nucleic acid which can self replicate and sustain life.
RNA can Fold in on itself to form a ribozyme which can catalyses reaction
5
Q
There is evidence that prokaryotic cells existed before eukaryotic cells. · Describe this evidence, including fossil evidence.
A
Fossils containing prokaryotic cells have been found to bee millions of years older than the oldest fossils that contain eukaryotic cells.
6
Q
What about the structure of mitochondria and chloroplasts indicates that they were involved in an endosymbiotic event?
A
- double membraned - the inner membrane is prokaryotic, outer membrane is eukaryotic
- both have prokaryotic (circular) DNA
