Name____________________________________2nd hour exam April 4, 2011 bio 44Answer all questions (6 point each)For each of the following, indicate in which organism the structure first appeared and the reason why the structure was developed 1. gills in vertebrates First appear in amphioxus and agnatha and is originally for filter feeding, not respiration2. pollen in plants First in pines and gymnosperms – better land adaptation than motile sperm, but dispersed by wind.3. feathers First in dinosaurs for thermal regulation 4. lungs in vertebrates First in lungfish and their ancestors for auxiliary breathing of air when in stagnant water with now oxygen.5. stomata in plants. First in mosses for retention of water and allowing gas exchange.Lots of structures or strategies for survival have their advantages and disadvantages. For each of the following, list some of the disadvantages of each and what factors favor the development of each despite thesedisadvantages.6. Flowers Advantage is use of insects, etc. to carry pollen, so you get more accurate pollination than with wind Problem is competition with others for insects – energy of production7. large seeds in plants Advantage is stored food for more growth of developing plant. Problem is you make fewer of them, they cant be dispersed by wind – need to develop other dispersal system8. being a seasonally deciduous plant Advantage is large surface area for photosynthesis Disadvantage is regrowth of leaves. If a short growing season – not enough time to regrow and catch up to Evergreens in energy production9. developing a constant body temperature (warm blooded) Advantage is longer period of activity and can colonize cold and hot climates – not limited in rangeDisadvantage is cost in energy consumption – insulation, etc.10. What is malnourishment and how does it lead to death in humans? Wrong kind of nutrients so you lack an essential material, like an amino acid. Start breaking down body Proteins, especially antibodies and loose immune response – die of infections.11. It seems obvious why desert plants have spines (cactus, etc.) but can you think of a natural experiment (one already conducted in the natural world) that would prove this? If spines are for protection, find a place where there is no need for protection = an island without herbivores – according to evolution, spines should be lost if not needed.12. Of all the major groups of organisms (animals, plants, etc.) which group is hardest to classify using a cladistic system. Why? Good answers are bacteria – due to lateral gene transfer and therefore no clean ancestor – descendent pathways13. What are the major differences between protostome and deuterostome animals? In embryos Protostome – first opening mouth,. Spiral cleavage, determinate cleavage Dueterostome – first opening anus, radial cleavage, indeterminate cleavage14. What are the major differences between prokaryote and eukaryote cells, and how do we think these differences came about?? Prokaryotic = bacteria, tiny, ring dna, no organelles or nucleus Eukaryotic – larger, chromosomes, organelles that we think were once free living organisms, and nucleus 15. Describe some changes (at least 2) in our classification of organisms that are due to the use of DNA analysis as opposed to morphological comparisons. Best are protostomes – switch from segmentation importance to exoskeleton and filter feeding Bacteria – from shape to archea and eubacteria based on biochemistry Some bird groupings, based on dna rather than structural similarity16. Why do mammals have an allantois and a yolk sac, and what purpose do these structures serve? Inherited from reptilian ancestors and retained as incorporated into placenta for embryo Nutrition (allentois in placentals, yolk sac in