BSCI124 Exam Guide 2 Lecture 8 Plant Diversity Taxonomic Hierarchy how organisms are classified 1 Kingdom 2 Division 3 Class 4 Order 5 Family 6 Genus 7 Species Binomial naming first name is genus second name is species Biological species concept a group of interbreeding populations offspring are fertile Lamarckism traits are acquired during the lifetime of an organism and passed to offspring use it or lose it individuals lost characteristics they don t require Darwin s Theory of Natural Selection o Examples the stretching of giraffes to reach leaves gives offspring longer necks o Variation members of a population have differences that are inheritable won t work with clones o Overproduction natural populations reproduce geometrically populations produce more than can survive o Competition individuals compete for limited resources o Survival to reproduce only the fittest survive and reproduce Artificial Selection selective breeding as practiced by humans on domesticated plants animals ex Dogs Gradualism evolution occurs as a slow and steady accumulation of changes in organisms Punctuated Equilibrium there are long periods of no change followed by a rapid change Lecture 9 Evidence for Evolution and Plant Adaptations Types of Natural Selection 1 Directional one trait at the extreme of the range is favored over individuals with the average or opposite extreme of the trait 2 Stabilizing the average trait is favored over the extreme traits 3 Disruptive the extreme traits are favored over individuals with the average trait Evidence for Evolution 1 Comparative analogy a Homologous organs similar in form in different organisms share common origin but may have different functions arm on human horse or dog b Analogous organs have a similar look function but do not share a common origin wing on bird wing on insect c Convergent evolution unrelated organisms in a similar environment evolve similar adaptive structures d Vestigial organs organs parts of organs that are non functional wisdom teeth 2 Mimicry harmless species may resemble a dangerous one coral snake is venomous milk snake is harmless but identical 3 Developmental Biology embryology early embryos fetuses of different species look very similar share common features 4 Biogeography each species has one place of origin they spread out until they encounter a barrier physical environmental ecological 5 Molecular Biology if we evolve from the same origin then DNA should be very similar people apes 6 Fossil Record give evidence of extinct organisms from millions of years ago the walking whale Coevolution long term evolutionary adjustment of one group of organisms to another characteristics of one organism evolve in response to specific characteristics of another Symbiosis ways in which 2 organisms can interact 1 parasitism interaction benefits one organism but hurts the other 2 commensualism benefits one doesn t affect the other 3 mutualism both organisms benefit Lecture 10 Viruses Prokaryotes Fungi Viruses non living cannot replicate reproduce on its own need a host to survive o Structure protein coat capsid for protection and nucleic acid DNA RNA for info on how to replicate o Virus is a cellular parasite uses host to replicate o Cause diseases HIV causes AIDS SARS influenza norovirus causes stomach flu HPV 6 Kingdoms of Living Organisms o Archaebacteria prokaryotic ancient live in harsh environments o Eubacteria prokaryotic have cell walls o Fungi mold mildew mushrooms have cell walls and roots o Protista algae slime molds protozoa cell walls but no cellulose o Plantae eukaryotes photosynthesis o Animalia eukaryotes obtain food by ingestion Prokaryotic do not have membrane bound organelles eukaryotic have membrane bound organelles Bacteria prokaryotic small uni cellular have no internal organelles haploid only o Structure cell wall chromosome plasmids o Replication asexual no mitosis binary fission o Feed most are heterotrophic obtain food from others some are autotrophic make their own food o Pathogens typhoid tuberculosis black plague syphilis gonorrhea o Control disinfectants antibiotics low oxygen o Uses yogurt insulin Endosymbiont Theory chloroplasts and mitochondria are descendants of once free living prokaryotes that were engulfed by larger cells establishing a mutually beneficial relationship Fungi eukaryotic non photosynthetic have cell walls haploid diploid o Basidiomycota form club0shaped basidia mushrooms o Zygomycota reproduce by forming zygospores bread molds o Reproduction sexual spores meiosis asexual spores mitosis o Feed fungi secrete enzymes that break down molecules o Structure most come in thread like strands called hyphae single strand are called yeasts o Commercial uses yeast for fermentation alcohol bread cheese Lecture 11 Algae Bryophytes Ferns Algae eukaryotes mostly photosynthetic o Can be mircro or macroscopic lack vascular tissues no xylem or phloem both sexual asexual o Benefits of Algae Algae of base of aquatic food chain photosynthetic Lichens algae fungi symbiosis Serve as shelter Provide oxygen 1 Diatoms live in cool oceans mostly unicellular a important for aquatic food chains 2 Kelps Brown Algae rocky coasts in cold water multicellular 3 Dinoflagellates mainly unicellular green colorless asexual reproduction Important in warm tropical ocean food chains a b Responsible for red tide 4 Red Algae oldest organisms on earth act as food for marine species a Structure thin films to complex filaments b Accessory pigments make it look red can photosynthesize in deep water c Commercial uses ice cream jelly syrup 5 Green Algae largest most diverse found in fresh water land a Important source of oxygen food for aquatic organisms Origin of Land Plants ancestor of land plants was green alga o Both have chlorophyll o Both have cellulose o Both have alternation of generations o Both form a cell plate Living on Land Issues Solutions a Obtaining enough water roots evolved b Preventing water loss cuticle evolved waxy layer c Getting enough energy photosynthesis easier on land tree grew taller d Photosynthesis water dilemma stomata open during the day for gas exchange close at night to recover from water loss e Multicellularity vascular tissues evolved f Sexual reproduction developed multicellular sex organs Bryophytes non vascular plants have a cuticle stomata Require moist environment have an alternation of generations o Gametophyte generation is dominant has rhizoids green stems roots produces eggs sperm o Sporophyte