Download presentation
Presentation is loading. Please wait.
Published byLynne Fowler Modified over 9 years ago
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
Diversity of Life 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
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
Prokaryotes Single cell Very small Cell wall Lacks nucleus Lacks membrane bound organelles Binary fission Domains: Bacteria and Archaea
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, O 2 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
Bacteria Share prokaryotic characteristics Causes some human diseases –Otherwise very important Decomposers and Nitrogen cyclers
9
Archaea Extremophiles –Tolerant to extreme environments –Extreme halophiles High salt concentration –Extreme thermophiles High and low temperature –Methanogens Anaerobic environments –Release methane
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
Trypanosoma Blood parasite Single encased flagellum African tsetse fly –Sleeping sickness Kissing bugs –Chagas disease
14
Amoeboids Pseudopodia –extensions of the cell Locomotion Feeding Various environments Various morphology
15
Ciliates Cilia to move and feed –E.g. Paramecium, Stentor, Vorticella Two nuclei types –Macronucleus Everyday activities –Micronuclei Sexual reproduction
16
Apicomplexans 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
17
Dinoflagellates 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
18
Diatoms 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
19
Multicellular protists 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
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.