Week 2 (origins of life) Flashcards
7 characteristics of life
1.Display Order (cell is the fundamental unit of life)
2. Harness and utilize energy(require energy )
3. Reproduce
4. Respond to stimuli (can make changes in response to external environment)
5. Exhibit homeostasis (regulate internal environment)
6. Growth and development
7. Evolve
cell theory
-all organisms are composed of one or more cells
-a cell is the smallest unit of life
-cells arise from pre existing cells
when did life begin ?
earth formed at around 4.6 BYA and 3.5 BYA prokaryotes evolved
what was the earliest organism and what did they diverge into ?
prokaryotes
into bacteria and archaea
when did O2 begin accumulating in atmosphere and why?
2.5 BYA
photosynthesis as it split water, releasing O2 as a product
Oparin and Haldane
described early earth as a reducing atmosphere / synthesis of organic compounds from inorganic
Miller-Urey Apparatus
-methane
-ammonia
-hydrogen
-water vapour
+spark
proved that organic molecules for life could be formed from inorganic components
polymerization
monomers combine to form a link called a polymer
protobionts
precursors to living cells
do not reproduce precisely
early protobionts are similar to liposomes
Eukaryotic cells
-came after prokaryotes
-arose from endosymbiosis
-generally larger and more complex
endosymbionts
mitochondria and chloroplasts
endosymbiosis
two organisms living together- one inside the other
-absorbed into
endomembrane
infolding of outside membrane to create inside membrane
first hereditary material ?
RNA
chromosomes in pro vs euk cells
prokaryote
-single circular chromosome
euk
-set of chromosomes located in nucleus
