Final Exam Study Guide - Ecology, Evolution and Society | BIO 301M, Study notes of Ecology and Environment

Download Final Exam Study Guide - Ecology, Evolution and Society | BIO 301M and more Study notes Ecology and Environment in PDF only on Docsity! BIO301M Final Exam Study Guide 1. Prokaryotic cells – a. Body plan: i. Semirigid, permeable cell wall usually surrounds the plasma membrane and helps a cell hold its shape and resist rupturing as internal fluid pressure increases ii. Capsule or slimy layer of polysaccharides, polypeptides, or both often encloses the wall; helps cells stick to surfaces and resist phagocytes iii. Many have more than one flagella that rotate like a propeller around the attachment site iv. Pili often project from cell wall that help cells adhere to surfaces b. Characteristics: i. No membrane-bound nucleus ii. Single chromosome iii. Cell wall in most species iv. Prokaryotic fission v. Metabolic diversity c. Metabolic diversity: i. Photoautotroph – make their own food by a photosynthetic pathway that uses sunlight and CO2 ii. Chemoautotroph – self-feeders that use CO2 and get energy by oxidizing organic compounds or inorganic ones iii. Chemoheterotroph – pirate energy and carbon from a living host d. Prokaryotic fission: i. A parent cell replicates its DNA molecule, which is then separated by a new plasma membrane ii. An orderly deposition of membrane and wall material at the midsection cuts the cell in two – each with a DNA molecule iii. Only bacteria and Archaea reproduce by this cell division mechanism e. Bacteria: smallest living organisms; most common and diverse prokaryotic cells, including i. Cyanobacteria ii. Gram-positive bacteria iii. Proteobacteria iv. Chlamydias v. Spirochetes f. Archaea: i. Methanogens – anaerobic ii. Halophiles – salt; anaerobic and aerobic iii. Thermophiles – hot areas; anaerobic 2. Sedimentary cycles – phosphorous and other solid nutrients that have no gaseous form a. Phosphorous is part of phospholipids and all nucleotides b. It’s the most prevalent limiting factor in ecosystems c. Main reservoir is Earth’s crust; no gaseous phase d. Human effects i. In tropical countries, clearing lands for agriculture may deplete phosphorous-poor soils ii. In developed countries, phosphorus runoff is causing eutrophication of waterways 3. Eubacteria – a. Cyanobacteria i. Photoautotrophs that help cycle carbon, oxygen, nitrogen, and other key nutrients ii. Like plants, they contain chlorophyll a and b and release oxygen during photosynthesis iii. Find most in aquatic habitats and soil b. Gram-positive bacteria i. Gram staining tints their thick, multilayered walls purple ii. Most are chemoheterotrophs iii. Endospore: type of resting structure that encloses the bacterial chromosome and a bit of cytoplasm 1. Resists heat, irradiation, drying out, acids, disinfectants, and boiling water c. Proteobacteria i. Makes up largest, most diverse bacterial group ii. Gram-staining tints their wall pink, so they are known as Gram-negative bacteria iii. Most common strain of E.coli lives inside the mammalian gut iv. There are photosynthetic proteobacteria, but they don’t release oxygen and they don’t use chlorophylls 4. Prions – small proteins a. Linked with human diseases i. Kuru ii. Creutzfeldt-Jakob disease (CJD) b. Animal diseases i. Scrapie in sheep ii. Bovine spongiform encephalopathy (mad cow disease) 5. Fungi general characteristics – a. Three lineages i. Zygomycetes ii. Sac fungi iii. Club fungi iv. Imperfect fungi are not yet classified b. All fungi are heterotrophs i. Cannot carry out photosynthesis ii. Must acquire organic molecules from the environment iii. Most are saprobes 1. Get nutrients from nonliving organic matter iv. Some are parasites 1. Extract nutrients from a living host c. Decomposers i. Break down organic compounds in their surroundings ii. Fungi carry our extracellular digestion and absorption 1. They secrete enzymes that digest organic matter into bits cells can absorb iii. Plants benefit because some carbon and nutrients are released d. Other roles i. Pathogens of plants, animals, humans ii. Spoilers of food supplies iii. Used to manufacture substances 1. Cheeses 2. Antibiotics e. Fungal foes i. Most fungi are vital decomposers and plant symbionts 12. Seedless plants – (vascular) a. arose from the Devonian b. Produces spores but no seeds c. Main groups: i. Lycophytes ii. Horsetails iii. Ferns d. Lycophytes: i. Tree-sized lycophytes lived in Carboniferous swamp forests – 1,100 modern forms are smaller and include club mosses e. Horsetails: i. As tall as trees, sphenophytes grew in Carboniferous swamp forests – 30 smaller species exist today, known as the “horsetails” f. Ferns: i. 12,000 species, mostly tropical ii. Most common sporophyte structure 1. Perennial underground stem (rhizome) 2. Roots and fronds arise from rhizome 3. Young fronds are coiled “fiddleheads” 4. Mature fronds divided into leaflets 5. Spores form on lower surface of some fronds g. Like brytophytes: i. Live in wet, humid places ii. Require water for fertilization h. Unlike brytophytes: i. Sporophyte is free-living and has vascular tissues 13. Tundra – a. Arctic tundra i. Occurs in high latitudes between polar ice cap and boreal forests ii. Summers are short and snow-free iii. Permafrost lies beneath surface, causes waterlogging in summer iv. Nutrient cycling is slow b. Alpine tundra i. Occurs at high elevations throughout the world ii. No underlying permafrost iii. Plants are low, cushions or mats as in Artic tundra 14. Phloem – a complex and alive vascular tissue a. Transports sugar b. Main conducting cells are sieve-tube members c. Companion cells assist in the loading in sugars (sisters) 15. Mammal groups – a. Three mammalian lineages i. Monotremes: egg-laying mammals ii. Marsupials: pouched mammals iii. Eutherians: placental mammals b. Living monotremes i. Three species 1. Dick-billed platypus 2. Two kinds of spiny anteater ii. All lay eggs c. Living marsupials i. Most of the 260 species are native to Australia and nearby islands ii. Only the opossums are found in North America iii. Young are born in an undeveloped state and complete development in a permanent pouch on mother d. Living placental mammals i. Most diverse mammalian group ii. Young developed in mother’s uterus iii. Placenta composed of maternal and fetal tissues; nourishes fetus, delivers oxygen, and removes wastes iv. Placental mammals develop more quickly than marsupials 16. Characteristics of mammals – a. Hair b. Mammary glands c. Distinctive teeth d. Highly developed brain e. Extended care for the young 17. Reptiles – a. Arose from amphibians in the Carboniferous b. Adaptations to life on land i. Tough, scaly skin ii. Internal fertilization iii. Amniote eggs iv. Water-conserving kidneys c. Reptilian radiation i. Adaptive radiation produced numerous lineages d. Extinct groups: i. Therapsids (ancestors of mammals) ii. Marine plesiosaurs and ichthyosaurs iii. Dinosaurs and pterosaurs e. Living reptiles: i. Crocodilians ii. Turtles iii. Tuataras iv. Snakes and lizards f. Turtles and tortuises i. Armor-like shell ii. Horny plates instead of teeth iii. Lay eggs on land g. Tuataras i. Only two living species ii. Live on islands off the coast of New Zealand iii. Look like lizards, but resemble amphibians in some aspects of their brain and in their way of walking h. Lizards and snakes i. Largest order (95% of living reptiles) ii. Most lizards are insectivores with small peg-like teeth iii. All snakes are carnivores with highly movable jaws i. Birds i. Only birds have feathers ii. Arose from reptilian ancestors 1. Feathers are highly modified reptilian scales 18. Deserts – a. Less than 10 cm (4 in) annual rainfall (episodic and sporadic), high level of evaporation b. Tend to occur at 30 degrees north and south and in rain shadows c. One third of land surface is arid or semiarid d. Soil isn’t rich in organic material 19. Ozone – a. Ozone thinning i. In early spring and summer ozone layer over Antarctica thins ii. Seasonal loss of ozone is at highest level ever recorded b. Effect of ozone thinning i. Increased amount of UV radiation reaches Earth’s surface ii. UV damages DNA and negatively affects human health iii. UV also affects plants, lowers primary productivity c. Protecting the ozone layer i. CFC production has been halted in developed countries, will be phased out in developing countries ii. Methyl bromide will be phased out iii. Even with bans it will take more than 50 years for ozone levels to recover 20. Monsoon – a pattern of wind circulation that changes seasonally a. Affect continents north and south of warm-water oceans b. Can cause seasonal variation in rains 21. Grasslands – a. Form in the interior of continents in the zones between deserts and temperate forests b. Warm temperatures prevail in the summer, and winters are extremely cold c. Drought-tolerant primary producers survive strong winds, sparse and infrequent rainfall, and fast evaporation d. Grazing and burrowing species are the dominant animals 22. Shrublands – a. Mediterranean regions b. In summer, vulnerable to lightning-sparked, wind-driven firestorms c. Shrubs have highly flammable leaves and quickly burn to the ground d. Highly adapted to episodes of fire and soon resprout from the root crowns e. Trees don’t fare as well in firestorms f. Shrubs that can withstand the fires have a competitive edge 23. Taiga – ii. When the population reaches carrying capacity, population growth ceases k. Logistic growth equation: G=rmaxN( K-N/K) i. G is the population growth per unit time ii. rmax is the maximum population growth rate per unit time iii. N is the number of individuals iv. K is the carrying capacity l. Overshooting capacity i. Population may temporarily increase above carrying capacity ii. Overshoot is usually followed by a crash; dramatic increase in deaths m. Density-dependent controls i. Logistic growth equation deals with density-dependent controls ii. Limiting factors become more intense as population size increases iii. Disease, competition, parasites, toxic effects of waste products n. Density-independent controls i. Factors unaffected by population density ii. Natural disasters or climate changes affect large and small populations alike o. Human population growth i. Population now exceeds 6 billion ii. Rates of increase vary among countries iii. Average annual increase is 1.26% iv. Population continues to increase exponentially p. Side-stepping controls i. Expanded into new habitats ii. Agriculture increased carrying capacity; use of fossil fuels aided increase iii. Hygiene and medicine lessened effects of density-dependent controls q. Future growth i. Exponential growth cannot continue forever ii. Breakthroughs in technology may further increase carrying capacity iii. Eventually, density-dependent factors will slow growth r. Fertility rates i. Total fertility rate (TFR) is average number of children born to a woman (2 theoretically, 2.1 actual) ii. Highest in developing countries, lowest is developed countries iii. When individuals are economically secure, they are under less pressure to have large families s. Population momentum i. Lowering fertility rates cannot immediately slow population growth rate ii. There are already many future parents alive iii. If every couple had just two children, population would still keep growing for another 60 years 28. Angiosperms – flowering plants a. Defining feature: i. Ovules and (after fertilization) seeds are enclosed in an ovary b. Two classes: i. Monocots and dicots c. Dominant land plants (260,000 species) d. Ground tissue system, vascular tissue system, dermal tissue system e. Eats water and sugar 29. Communities – all the populations that live together in a habitat a. Habitat is the type of place where individuals of a species typically live b. Type of habitat shapes a community’s structure c. Factors shaping community structure i. Climate and topography ii. Available foods and resources iii. Adaptations of species in community iv. Species interactions v. Arrival and disappearance of species vi. Physical disturbances 30. Parasitoids – insects that develop inside another species of insects, which they devour from the inside out as they mature a. Always kill their hosts b. 15% of all insects c. Commercially raised with parasites and released in target areas as biological controls 31. Island biota – a. Distance effect i. Islands that are far from a source of potential colonists receive few colonizing species, and the few that do arrive are adapted for long-distance dispersal b. Area effect i. Larger islands tend to support far more species than smaller islands the same distances from a colonizing source ii. Larger islands tend to offer varied habitats and more of them iii. Most have complex topography and higher elevations iv. Such variations promote diversity v. Larger islands intercept more of the accidental tourists that winds and ocean currents move from the mainland but offer no way back c. Number of species will reflect a balance between immigration rates for new species and extinction rates for any established ones d. Small islands distant from a source of colonists have low immigration rates and high extinction rates, so they support fewer species once the balance has been struck for their populations SINGLE CELLED, PROTISTAN LIKE ANCESTORS