BIOL 1202 : Test 1 Study Guide
Document Summary
50 trillion: before fossil records no multicellular organisms, earth is about 4. 5 billion years old, observational fact. 3 domains: we first rose about 200 thousand years ago, animals and fungi share a common ancestors. 2 billion years ago we only had prokaryotes- bacteria and archaea. 4 billion years ago we had life on planet (gave us 10 million species that can be placed on family tree that came from the single life form on this planet( bacteria) 8 to 10 million species on the planet. Earth is 4. 5 billion years old life created. Cells that make up the human body -50 trillion cells. All cells come from pre-existing cells that come from haploid egg, and sperm. All life on the planet comes from a common ancestor therefore all life on the planet is related to all other life on the planet. All life on earth is the biggest group of living organisms that we know of.
