Where we’ve been

1. Where we’ve been • To understand one aspect of biology we dig a bit deeper to first learn the parts that make up the whole • To know evolution, you must know something about genetics & heritable traits …before that, you need to understand, cellular reproduction, proteins, & DNA …before that, how a cell works, how a protein comes about, what makes up DNA …membranes, organelles …even down to molecules, atoms, etc.

2. Where we’re going • Evolution & natural selection explains the vast natural diversity of life… all the various organisms that we have Organismal interactions Population Dynamics Communities Biomes Ecosystems

3. Hierarchy = organizational levels Domain Kingdom Phylum Class Order Family Genus Species Each level is nested within the one above Broad or less specific More specific Diversity of Life

4. Closely related species belong to the same genus, similar genera are included in a family, etc…Species that share the same structures, behaviors, etc, can interbreed and produce fertile offspring.

5. Grouped by shared characters (Evolutionary relationships) Embryology Reproduction strategies Symmetry (body plan) Morphology Feeding mode Etc…

6. Single cell Very small Cell wall Lacks nucleus Lacks membrane bound organelles Binary fission Domains: Bacteria and Archaea Prokaryotes

7. Organizing prokaryotes • Morphology • E.g. bacilli, cocci, spirocheates • Biochemistry & cell walls • Using stains to determine structural differences • Adaptations to environmental variations • salinity, temperature, pH, O2 levels • Modes of nutrition • Heterotrophic (hetero = other, trophic = food or feeding) • Must consume organic molecules • Autotrophic (self feeding) • Photoautrophic can photosynthesize; get energy from sun • Chemoautotrophic obtain energy from inorganic molecules

8. Share prokaryotic characteristics Causes some human diseases Otherwise very important Decomposers and Nitrogen cyclers Bacteria

9. Extremophiles Tolerant to extreme environments Extreme halophiles High salt concentration Extreme thermophiles High and low temperature Methanogens Anaerobic environments Release methane Archaea

10. Eukaryotes • Protista, Fungi, Planatae, Animalia • Complex • >10x larger • DNA in nucleus • Cell membrane • Some also have cell wall • Membrane bound organelles • specialization

11. Protista • Very diverse • Single celled & multicellular • Autotrophs • Plant-like • Heterotrophs • Animal-like protozoans • Fungal-like • Aquatic or moist environments • Varies in modes of reproduction, locomotion, & morphology

12. Diplomonads • Spore forming • Two nuclei • Multiple flagella • Usually anaerobic • E.g. Giardia • Intestinal parasite • Contaminates streams • Causes severe diarrhea

13. Blood parasite Single encased flagellum African tsetse fly Sleeping sickness Kissing bugs Chagas disease Trypanosoma

14. Pseudopodia extensions of the cell Locomotion Feeding Various environments Various morphology Amoeboids

15. Cilia to move and feed E.g. Paramecium, Stentor, Vorticella Two nuclei types Macronucleus Everyday activities Micronuclei Sexual reproduction Ciliates

16. Parasites Apex structures for penetrating host cells Lack cilia, flagella, or pseudopods E.g. Plasmodium Malaria Enters and feeds on red blood cells Spread by mosquitos Apicomplexans

17. Two flagella in grooves Spinning flagellates Phytoplankton Photosynthesizing aquatic species Red tides red pigments along with chl a Some are toxic Shell fish accumulation Bioluminescence Dinoflagellates

18. Phytoplankton Silica cell wall Glass-like Two halves like a petri plate Mitotically divide the halves Secretes the smaller half Nucleus triggers meiosis when too small Diatoms

19. Phaeophyta Brown algae E.g. Macrocystis kelp Rhodophyta Red algae Chlorophyta Green algae E.g. Ulva, sea lettuce Lack true stems, leaves, roots as in plants Multicellular protists