IB Biology: Evolution

28 flashcards · Other · by Gabrielle Wong

1. Evolution: cumulative changes in the heritable characteristics of a populatoin

   The mechanism for evolution is natural selection. Evidence of this: fossils radioactive dating ex. carbon dating artifical seelction adaptive radiaiton vestigal organs

2. Convergent evolution: the independent evolvement of similar features due to shared needs

   Example: wings in many species

3. Divergent evolution: one common ancestor split into different species/breeds with varying characteristics

   Example: development of different beaks among finches on Daphne Major

4. Homologous structures: dissiimlar form, similar background, a result of common ancestry

   Example: beaks

5. Analogous structures: similar function, dissimilar background, a result of common needs

   Example: wings

6. Vestigial organs: structures now lacking function

   Example: appenxix in humans

7. Transient polymorphism: the morphing (changing) over space

   Example: develompent of melanistic moths during the Industrial Revolution

8. Clades: grouping of taxa based on chronological evolution of traits

   Clades are depicted with cladograms, where a node is a point of separation, and distance on the cladogram is a represenation of how far, evolution-wise, organisms are

9. Natural selection: The process whereby heritable characteristics in organisms become more or less prevalent based upon reproductive success and the interaction of organisms with their environment, the mechanism of evolution Process of natural seleciton: Variation - due to alleles, variations, meisosis, sexual reproduction For species, this leads to: overpopulation competition for resources useful variations alllow an organism to better compete more likely to survive more likely to reproduce wil…

   Examples: development of melanistic moths antibiotic-resistant bacteria pesticide-resistant rats

10. Binomial system: Classification system for organisms using the genus and species name; genus is capitalized, species lower case and both terms are underlined or italicized Order of taxa: Species-Genus-Family-Order-Class-Phyla-Kingdom-Domain

    Way to remember the order: Silly Great Family of Chimps Poach Katie's Dinner"

11. Bryophyta: moss plants short and non-vascular no flower, no roots, no leaves, no stems reproduce using water and spores

    Examples: moss, liverword, bank haircap, hornwort

12. Filicinophyta: filament plants vascular no flowers triangular fronds made from small, thin leaves reproduce using spores under leaves

    Examples: ferns, bracken

13. Coniferphyta: cone-bearing plants vascular woody stems, waxy needle-like leaves reproduce with seeds in cones and the wind

    Examples: pine trees, juniper, cedar, evergreens

14. Angiospermophyta: container for sperm plants vascular produces flowers and fruits has leaves, roots, stems reproduce with seeds in flowers, transported by animals ex. bees

    Examples: flowers, fruit trees

15. Mollusca: thin-shelled, mostly marine soft and unsegmented body have shells, usuall made of calcium onoscular foot for locomotion radulla for scraping of food

    Example: clam, snail

16. Porifera: pore bearing, mosty marine, but not freshwater sponges no oragns or tissues branching cavities with complex folds stuk in place, draw in food and water through pores

    Examples: yellow tube sponge, bath sponge, finger sponge

17. Cnidara: nettle, mostly marine single opening sac bodies tentacles radially symmetrical stinging capsules

    Examples: jellyfish, sea-fan

18. Enchindermata: sea urchin skin, marine radially symmetrical spiny skinned exoskeleton canals to extend feeding tube

    Example: sea stars, sand dollars, sea urchin, sea cucumber

19. Platyhelminthes: flat worm, marine bilaterally symmetrical soft-bodied flat, unsegmented shape free living or parasites

    Examples: tapeworms, trematdua

20. Annelida: ring, marine and land ring-like segments most have external bristles gastic tract with 2 openings

    Examples: earthworm, clamworm, leeches

21. Anthropoda: joint foot, marine and land segmented chiting exoskeleton legs and joint appendages for walking, defense etc.

    Examples: spider, mites, shrimp, centipede, millipede

22. Nematoda: thread, land thin, unsegmented, cynlindrical body tapered ends thrashing movements feed off micro-organsisms or live as parasites

    Examples: hookworm, pinworm

23. Chordata: chord/line, land and water notocord (flexible rod across body) dorsal/hollow nefve chord gill slits tail

    Examples: fish, humans, sea squirts

24. Cephalasidorphi: head shield jawless come with a well armoured head shield Myxini: jawless feed on dead and dying fish elongated and slimy

    Examples: lamprey (ceph.) and hagfish (myxini)

25. Osteochythes: bone fish fish with bones small and scaly skin usually use external fertilization Chondrichythes: cartilage fish fish with cartilage paired fins and nares

    Examples: salmon (osteo.) and sharks, rays, chimeras (chond.)

26. Amphibia: ectothermic vulnerable to drying out absorb O2 through skin Reptilia ectothermic waterproof scaly skin air breathing

    Examples: salamander, frog, toad (amph.), turtle, snake, lizard, crocodile (rept.)

27. Aves: aviator = birds adaptions for flight (ex. wings) honey-combed bones good vision and hearing endothermic two legs Mammalia = hair, mammals mammary glands for milk large brains

    Examples: birds (aves), bats, deer, dogs, humans (mammals)