Flashcards
Bio Midterm 1
Cards in this deck (51)
- 1Harvey Weinberg equilibriump^2 + 2pq + q^2 = 1
- 2Harvey- Weinberg Principlep represents dominant allele frequency, q represents recessive allele frequency. p^2 gives homo-dominant, 2pq gives heterosexual and q^2 gives homo-recessive
- 3Harvey-Weinberg Caveatsworks for populations that have no mutation, mating is random, very large, no gene flow and no natural selection
- 4Extinction VortexSmall pop -> inbreeding/random genetic drift -> loss of genetic variability -> reduction in individual fitness & population adaptability -> lower reproduction/higher mortality -> smaller population
- 5Inbreedingleads to higher probability of expressing deleterious alleles. Can cause inbreeding depression
- 6Gene Flowtends to reduce variation in populations over time & movement of alleles among populations
- 7Bottleneck Effectwhen population experiences a dramatic decline and some alleles are left behind and others will be lost or fixed
- 8Founder Effectwhen a few individuals become isolated from a larger populations and some alleles are left behind and some are lost from drift. New populations will have different genetics from old pop
- 9Relationship between Drift & Selectiondepends on populations size and selection strength. Higher strength lets selection take over, lower population lets drift takeover
- 10Genetic DriftUnpredictable fluctuations in allele frequencies that are more noticeable in small populations. Within populations there is fluctuating variation. Unpredictable between populations. Tends to reduce genetic variation through loss of alleles
- 11Paralogous Geneshomologous copies formed by duplication within a genome. The gene can duplicate and diverge, creating redundancy
- 12Homeotic Genesdetermine basic features such as where wings are located and are considered the 'tool kit for development'. Duplication of these homeotic genes is often linked to new morphological forms
- 13Balancing selectionheterozygous selection is a form of balancing selection
- 14Frequency Dependent Selectionthe rarer genotype has the advantage
- 15Selection Against Deleterious Alleleinfinite
- 16Shared Derived characteristicsA novelty; e.g. vertebral column, hair
- 17Shared ancestral characteristicsA characteristic common to a whole group; e.g. hair in mammals
- 18Monophyletic group (Clade)is a group that includes an ancestral tax and all (and only) its descendant
- 19Paraphyletic Groupincludes common ancestor and only some of it's descendants
- 20Polyphyletic Groupincludes branches whose most recent common ancestors are different
- 21Analogiessimilarities not attributable to common descent
- 22Homologiessimilarities attributable to common descent; can be only present in embryos
- 23Convergent Evolutionis the evolution of similar or analogous features in distantly related groups
- 24Vestigial Structuresstructures we no longer need but still have
- 25Molecular Analogies (homoplasies)the result of some mutation occurring independently in two different lineages
- 26Prokaryotesdate back 3.5 billion years. Very small, cell wall, circular genome, no nucleus. began oxygenic photosynthesis and created oxygen revolution 2.7 to 2.3 billion years ago
- 27Photoautotrophenergy source: light
carbon source: CO2, HCO3, or other related compound
e.g. photosynthetic prokaryotes - 28Chemoautotrophenergy source: inorganic chemicals
carbon source: CO2, HCO3, or other related compound - 29Photoheterotrophenergy source: light
carbon source: organic compounds - 30chemoheterotrophenergy source: organic compounds
carbon source: organic compounds - 31Endosymbiont Theoryendosymbiont is a cell that liven w/in a host cell. ancestors of mitochondria and plaids gained entry into cell and became organelles
- 32Serial Endosymbiosismitochondria evolved before plastids through a sequence of endosymbiotic events
- 33Protisteukaryotes are neither plant, animal or fungi. most lineages have endosymbiotic origins. more structural and functional diversity and most nutritionally diverse
- 34Diatomunicellular algae that form major component of phytoplankton
- 35Dinoflagellatesdiverse group of aquatic phototrophs, mixotrophs and heterotrophs that have endosymbiotic relationship with reef building coral
- 36Fungi100000 species known, 1.5m may exist. mushrooms are reproductive structure. Efficient decomposer of organic material. 1/3 of fungi use dead organic matter as food source
- 37Lichensymbiotic association between a photosynthetic micro organism and a fungus
- 38Mycorrhizaemutual symbiosis between fungi and plant roots. fungi delivers phosphate ions and minerals to plants. plants give sugar
- 39Alternation of generationsgametophytes are haploid, reproduce through mitosis then fertilize. sporophyte
- 40Land Plantsa monophyletic group can be split into vascular and in vascular (moss)
- 41Angiospermsflowering plants, are about 75% of land plants and account for land plant diversity. 1st to colonize land
- 42Animalsare heterotrophs, most reproduce sexually and mostly diploid. most have a larvae stage
- 435 important animal relationships- a monophyletic group
- sponges are basal animals(first to diverge)
- true animals are everything except sponges
- most animals are bilateral symmetry front& back
- most animals are invertebrates - 44Adaptationan inherited trait enhancing the survival and reproduction of an organism in a particular environment
- 45Evolutionary Fitnessextent to which an individual contributes genes to future generations
- 46Survival of the Fittest-reproduction is necessary for fitness
-bigger and stronger is not always better
-implies that natural selection is all or nothing - 47Directional Selectionheight stays the same but shifts to one direction
- 48Disruptive Selectionshifts to double peaks at extremes
- 49Stabilizing Selectionheight increases, gets skinnier towards middle
- 50Evolution by Natural Selection- mutations are random w respect to environment
- selection is not random w respect to phenotype - 51Gene by Environment Interactionsame gene expressed by environment interaction. Leads to phenotype plasticity. e.g you get a tan from sun