Lecture 17 Flashcards
What are the three super-kingdoms?
Bacteria, Archaea, Eukaryotes
What are the six kingdoms of organisms?
Bacteria,Archaea,Protista, Plantae, Fungi, Animalia
What are the characteristics of the kingdom Bacteria?
-unicellular -cells lack nuclei and membrane-bound organelles -distinctive cell walls -some autotrophs and some heterotrophs
What are the characteristics of the kingdom Archaea?
-unicellular -cells lack nuclei and membrane-bound organelles -distinctive cell walls -some autotrophs and heterotrophs
What are the characteristics of the kingdom Protista?
-unicellular or multicellular -cells with nuclei and membrane bound organelles -some have cell walls -some autotrophs and heterotrophs
What are the characteristics of the kingdom Plantae?
-multicellular land plants -cells with nuclei and membrane bound organelles -cell walls of cellulose -autotrophs -complex organ systems
What are the characteristics of the kingdom Fungi?
-most multicellular thread-like hyphae -cells with nuclei and membrane bound organelles -cells walls of chitin -heterotrophs (by absorption)
What are the characteristics of the kingdom Animalia?
-multicellular -cells with nuclei and membrane bound organelles -no cell walls -heterotrophs (by ingestion) -complex organ systems
How does evolution arise?
Evolution through natural selection. All living organisms result from descent, with modification, from a common ancestor, and share a common cellular biochemistry and genetics.
Where did life first evolve and how?
The Origin of Life in Primitive Oceans! 1. Primitive Oceans - a dilute, hot, smelly soup of ammonia, formaldehyde, formic acid, cyanide, methane, hydrogen sulfide and organic hydrocarbons. 2. UV light contributed to organic synthesis, yet UV light also destroys organic molecules. 3. Therefore, life evolved in the oceans, protected by water that filters out the UV.
Is it possible that primodial oceans were cooler than we thought
-yes, possibly got cool about half a billion years before we thought= so more time for evolution.
What do we know about the first cells?
• were prokaryotic • were heterotrophs-and liked it hot! (or did they?) • are not in the fossil record • First fossils reveal photosynthetic Cyanobacteria, which eventually changed the earth’s atmosphere forever by generating oxygen.
What is today’s atmosphere like?
• photosynthesis resulted in an oxigenic atmosphere • is 21% oxygen, a oxidizing atmosphere where the spontaneous formation of complex carbon molecules cannot occur • shielded from ultraviolet radiation by a layer of ozone gas (O3) in the upper atmosphere.!
What is the snowball earth?
snowball= 10million yrs ago ice age that kept on going and stopped evolution- plants- organisms survived around volcanoes=warmer
What is the evidence for evolution? (5)
• Palaeontology and the fossil record • Comparative anatomy of cells and organisms • Embryology • Comparative biochemistry and molecular biology • Structure of DNA, gene sequences