History of life Flashcards
What is the Big Bang theory? How old is the universe?
A massive explosion that brought time space and matter into existence which is ongoing so the big bang is still ongoing. The universe is 14 billion years old.
What is the Big Bang theory? How old is the universe?
A massive explosion that brought time space and matter into existence which is ongoing so the big bang is still ongoing. The universe is 14 billion years old.
What is the approximate age of the earth?
4.6 billion years
What were the conditions of the early earth?
NO oxygen, radiation, lightning, hostile, ammonia, methane, hydrogen gas volcanoes, water vapor, hotter than boiling
What is spontaneous generation?
the theory that life appears from nonliving things
What are the four main stages in the origin of life?
1: abiotic synthesis of small organic molecules.
2:macromolecules
3:packing of macromolecules into membranes (protocells)
4: origin of self replicating molecules.
What experiments did Stanley Miller perform?
he demonstrated abiogenesis of small organic molecules by placing simple molecules in a chamber and introducing electric sparks, which generated simple organic molecules like amino acids.
what are protocells ?
simple vesicle-like structures that harbor nucleic acids and a wide array of various molecules.
What makes the origin of DNA and protein problematic?
protein cannot form without the instructions from DNA, but DNA cannot form without protein.
What is the RNA world hypothesis?
The hypothesis that RNA was the first nucleic acid to evolve and early life was based on RNA rather than DNA or proteins.
When did each of the following events occur in the history of life on earth? (prokaryotic cells, free
oxygen in the atmosphere, eukaryotic cells, multicellular life, animals, modern humans
prokaryotic cells-3.5B
oxygen-3.0B
eukaryotic-2.0B
multicellular life-1.5B
animals-1.0B
humans-100k
What is the endosymbiotic theory?
the endosymbiotic theory states that the mitochondria and chloroplasts in eukaryotic cells where once aerobic bacteria that where ingested by a large anerobic bacteria.
who proposed the endosymbiotic theory? what is the evidence?
Lynn Margulis. the prokaryotic cells is similar to the mitochondria in shape and function. its genes are homologous to those of bacteria. both have their own ribosomes. both perform binary fission.
when were the Paleozoic, Mesozoic, Cenozoic eras?
Paleozoic- 600m to 250m
Mesozoic- 250 to 65
Cenozoic- 65 to now.
which organisms dominated each era?
Paleozoic-fish, amphibians, ferns.
Mesozoic-reptiles, conifers.
Cenozoic-mammals, flowering plants.
