Lecture 1

• Infoldings in the plasma membrane gave rise to

  endomembrane components, such as the nucleus and endoplasmic reticulum
• Margulis found the origin of mitochondrion and chloroplasts and said that symbiosis drives evolution
• The mitochondrion is the ancestor modern eukaryotic heterotrophic eukaryotes
• In the first endosymbiosis event, the ancestral eukaryotes consumed aerobic bacterium that evolves into the mitochondrion
• Chloroplasts are the ancestor to modern eukaryotic photosynthetic organisms
• During the second endosymbiosis event, the ancestral eukaryote consumed photosynthetic bacterium that evolves into chloroplasts
• Evidence of the origin of mitochondrion and chloroplast is based on similarities of extant prokaryotes
• After primary endosymbiosis, photosynthetic line diverged to red and green alga lines
• Algae are photosynthetic eukaryotes with chlorophyll a and no embryo stage
• Secondary endosymbiosis occurs many times
• Phylogeny is tracing evolutionary history of organisms
• Systematics is classifying organisms based on a phylogeny
• Characteristics that distinguish organism groups are structures/functions, ultrastructure (electron microscope), biochemistry, and molecular evidence
• The third kingdom (Protoctista and Protista) was invented when the microscope was invented
• Protoctista and protista were invented by John Hogg and Ernst Haeckel
• Whitaker recognized 5 kingdoms, but there was a flaw in kingdom Protista
• Protista is polyphyletic, unlike other classifications
• All protista, plants, animals, and fungi were integrated into supergroups
• Supergroups show how eukaryotes are related
• There are 6 supergroups
• Most protists are unicellular. Unicellular members are the most complex eukaryote cells because they carry out all functions of the organism and have a division of labor
• Protists are sexual and asexual
• The DNA in the mitochondria is not older than the DNA in chloroplasts
• Protists reproduce sexually with environmental change
• Protists are all eukaryotes
• The earliest fossils are those of bacteria
• Bacteria in prokaryotes have large cells
• All eukaryotes are descendants of a common ancestor
• The last common ancestor of eukaryotes had: cells with nuclei surrounded by a nuclear envelope with nuclear pores, mitochondria, cytoskeleton of microtubules and microfilaments, flagella and cilia, chromosomes with histones, mitosis, sexual reproduction, cell wall
• Eukaryotes have cells with nuclei and cytoskeletal elements
• Endosymbiosis is when one cell engulfs another and both cell survive and benefit
• Eukaryotes have aerobic respiration in their mitochondria and some prokaryotes have aerobic respiration
• Mitochondria produce ATP using aerobic respiration
• Endosymbiotic theory states that eukaryotes could've formed from one cell engulfing another and living in that other one, evolving and no longer sharing genetics
• The mitochondria is in all eukaryotic cells
• The mitochondria can be round, worm-shaped, and have intricate branches; they have their own genome with circular chromosomes
• Mitochondria were free-living aerobic organisms but cannot survive and reproduce outside the cell today
• Mitochondria have special ribosomes and transfer RNAs that resemble these same components in prokaryotes.
• Mitochondria reproduce similarly to binary fission in prokaryotes
• Some eukaryotes can't live in too much oxygen