1stLivingThingsLEC19 Flashcards
What were Earth’s sole living inhabitants for how many years?What do they do as they evolve?
Prokaryotes (bacteria & archea).
1.5 billion years.
They change the condition of the earth.
The first organisms to do photosynthesis & produce oxygen are what? when did they appear?
Cyanobacteria! 3.5 billion years ago.
They are still doing fine today.
What prokaryote is a rich source of vitamins and protein in Africa & Mexico?
Cyanobacterium spirulina!
What new natural fuel system will recycle CO2?
The convertion of CO2 into fuel through modified Cyanobacteria.
When did oxygen began to build in the atmosphere?
2.7 billions years ago!
Oxygen-making organisms caused one of first extinction.
Oxygen is toxic to plants, any anaerobic organisms.
What organisms were driven away to areas where oxygen can’t reach?
Anaerobic organisms!
Eons later the growth of photosynthetic organisms almost caused another mass extinction. What is example?
Snowball earth!
The oldest eukaryotic fossils were tiny algae that date back how many years?
2.1 billion years ago!
How did first eukaryotic cells evolved? Through what process?
They arouse from prokaryotes, through the process of endosymbiosis!
What proposes that mitochrondria and chloroplasts were formaly small prokaryotes living in host cells?
The theory of endosymbiosis!
When did the earliest multicellular eukaryotes appear?
1.5 billions of years ago!
The first multicellular organisms were what?
Colonies!
What is colonies?
Clusters of autonomously replicating cells.
Major animals appear suddenly. This is called the what? When did it take place?
The Cambrian Explosion!
540 million years ago.
Dating from the Proterozoic eon during the Camdrian period 542mya, what are the two oldest animal groups?
Cnidarians(Jellys) and Porifera(Sponges)!
