Exam 1 PDF - Biology Past Paper

· Adaptations heritable traits - that help individuals survive/reproduce in their current environment · Natural Selection - increases...

· Adaptations heritable traits - that help individuals survive/reproduce in their current environment · Natural Selection - increases the frequency of advantageous traits in the population over time · Biological Fitness - individuals who are best adapted to their environment Natural Selection 1 Stabilizing selection directional um selection disruptive selection · favors intermediate · favors one extreme · the two extremes phenotypes are favored Genetic Drift-random change in sele frequency Gene Flow-movement of alleles between populations Mutation-creation of new alleles Speciation · the formation of two species from an ancestral species · concept criteria advantages disadvantages I I I I reproductive isolation evolutionary independence N/A to a sexual biological species/fossil species morphological distinction widely applicable subjective morphological - differences physically (may misclassify) species on the smallest widely applicable lack of good tree Phylogenetic da+a tip on the tree Reproductive Isolation once species become isolated they longer exchange - can no genes. - the separation becomes more distinct and new mutations Soon create a new species Prezygotic and Postzygotic · prezygotic prevents the - formation of a zygote Temporal Isolation · species breed at different times - - Habitat Isolation different habitats - - Behavioral Isolation - different courtship rituals - MechanicalIsolation reproductive organs are incompatible - - Gametic Isolation gametes incompatible - are postzygotic isolation is produced but fails to develop · a zygote - or is sterile Hybrid Inviability - embryos do not survive - - Hybrid Sterility offspring are - not fertile Allopatrio/Sympatric Speciation · Allopatric populations are separated from each = other(geographic) dispersal : individuals disperse and colonize a habitat - new - vicariance : physical barrier forms/separates a species populations may diverge and be longer to interbreed - no Sympatric reproductively isolated who physical barrier · : eX thin and thick-lipped cichlids -. - polyploidy ; having more than I sets of chromosomes - autopolyploidy : a diploid plant produces diploid gametes instead of haploid ones ; after fertilization that diploid can produce tetraploid offspring Phylogeny - the evolutionary history + relationships of an organism of or group organism tips A B C D 7 7 M branch [ -represents nodes - speciation lineage events root-common ancestor Monophyletic Clade - a common ancestor and all descendants of that ancestor nested within another (smaller clades in large one · one a Paraphyletic Group - includes a common ancestor and some but not all , descendants Synapomorphies - shared derived characters of monophyletic group Homologous traits - traits that similar due to common ancestry · due to synapomorphies AnalogousTraits - traits that are similar but were not inherited from a common ancestor · they involved independently via convergent evolution Sister Groups - descendants that split from the same node · closest relatives Outgroup-taxon that is outside the groups of interest Taxonomy - the science of classifying organisms Domain gametes gametes IN - meiosis fertilization 2N zygate diploid S adult Alternation of Generations - "SPORIC MELOSIS" - meiosis = haploid spores gametophyte mitosis mitosis gametes - = spores red ex. algae 7 - N kelp gametes meiosis( haploid > - V 2 > fertilization diploid ↳ contains zygote sporangia Sporophyte S Ecological/Economical Importance of Protists · Positive Impacts photosynthesis (primary producers) - - Phytoplankton (food chain) - nutrition · Impact on human health/welfare can cause human disease and crop disease - eX. Irish potato famine · Apicomplexans photosynthetic plastid - non parasitic - - forms infections spores Trypanosoma · - causes sleeping sickness in humans - affects nervous system Ecological Impacts · - red tides · caused by blooms of dinoflagellates · fish kills · human headaches Shellfish poisoning ~