Domains Of Life Flashcards
(12 cards)
What is a prokaryote?
A bacterial cell without a membrane surrounding it’s DNA (NO NUCLES)
What are the 3 domains of life?
Bacteria archaea eukarya
List features of bacteria cells?
Cell wall, cytoplasm, ribosomes, long DNA molecule, flagella, cell membrane
What was the first evidence of bacteria?
Layered fossils in risk from mineralized warm springs 3.5 billion years ago
What is archaea?
- most similar modern domain of organisms to the original life form
What are archaeans? And were are they found?
Earths first inhabitants, today are found in most extreme environments
What are eukarya?
- have cells with a nucleus and other structures enclosed within membranes
- nucleus is necessary as DNA is at risk if enzyme degradation when food is taken in
- eukarya line evolved 3.5 billion years ago
How did mitochondria arise in eukaryotes? What evidence is there for this?
By an engulfment process, where aerobic bacteria were enslaved to produce more energy using oxygen. Double membrane, own DNA, divide by binary fission (bacterial asexual reproduction) pelomyxa has no mitochondria but symbiotic bacteria
What are the 6 most important changes in Eukaryote evolution?
Mitochondria, motor proteins, photosynthesis and chloroplasts, mitosis, multicellularity, sex
List similarities of Eubacteria and Archaea
Prokaryotes, can have capsules, have flagellum, have DNA, cell membrane + cytoplasm, reproduce asexually, can be heterotrophs or autotrophs, similar shapes/sizes, ribosomes, cell walls
Elements of archaea that eubacteria DO NOT have
Diverse metabolism since O2 is required, found in extreme environments, nono layer of lipids with branched side chains, no proof of being associated with diseases, cell wall doesn’t contain peptidoglcan
Elements of Eubacteria that ARE NOT in archaea
They are anaerobic, found everywhere, have plasma membrane, cause human diseases, cell wall contains peptidoglcan
