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Biology Exam
General Bio B110 CH. 20 - 25
| Question | Answer A | Answer Part B | Answer Part C |
|---|---|---|---|
| CH 20: Modern Antarctica | Devoid of almost all life, but didn't used to be that way | Paleontologists have found signs that indicate past life included: dinosaurs, reptiles, mammals,flightless birds, ferns, trees, amphibians, freshwater fish, + aquatic beetles | |
| Fossils (What are they? What do they do?) | preserved remains or impressions of individual organisms that lived in the past (often found in sedimentary rock) | provide evidence that past organisms were unlike current organisms -> life has evolved th/o time | ages of fossils correspond to their order in the fossil record |
| Example (Fossils) | Precambrian Invertebrate,Trilobite, Seed Fern, Termite (in amber), Velociraptor, petrified tree trunk | ||
| Radioisotopes | unstable, isotopic forms of elements that decay to more stable forms over time | used to determine fossil dating by dating rock above and below the fossil that does not contain radioisotopes of its own | Ex: carbon 14, uranium 235 |
| Why is the fossil record incomplete? | b/c most organisms decompose rapidly | fossils that are formed can be destroyed by common geologic process (erosion, extreme heat or pressure) | unique set of circumstance is required to form, preserve, + discover fossils -> creates large gaps in fossil record |
| What groups of mammals are whales closely related to? | artiodactyls -> hoofed land mammals (cows, hippos) | seen: changes in ankle bone structure | |
| What 3 events does the study of life on Earth focus on? | origin of cellular organisms | beginning of multicellular life | colonization of land |
| Timeline (Part 1) | Precambrian (4.6 bya) origin of life | Cambrian (540 mya) invertebrates fill the sea | Ordovician (490 mya) plants + fungi begin to colonize land |
| Timeline (Part 2) | Silurian (445 mya) diversity in fish | Devonian (415 mya) amphibians appear | Carboniterous (360 mya) Earth covered in forests |
| Timeline (Part 3) | Permian (300 mya) age of reptiles begin | Triassic (250 mya) dinosaurs evolve + spread | Jurassic (200 mya) large dinosaurs (no stegosaurus) yes t-rex |
| Timeline (Part 4) | Cretaceous (145 mya) increase in flowering plants, extinction of last dinosaurs | Paleogene/Neogene (65 mya) age of mammals begin | Quaternary (2.6 mya) humans evolve |
| About how many species have been described and cataloged by biologists? | About 1.7 million | EXTRA: species alive today represent less than 1 % of all species that have ever lived on Earth | |
| CH 21: Biosphere + Ecology | Biosphere - includes all the organisms on Earth together w/ the physical environments in which they live | Ecology - the scientific study of biotic + abiotic environments and organisms that live in them (form a web of interconnected relationships) | |
| Predator-Prey Relationships | - rabbits introduced in Australia, dingos didn't know to hunt them at first, so they ate most of the greenery + depleted food sources for other herbivores | ||
| Climate | the prevailing weather conditions experienced in a region over long periods of time | * strongest environmental influence of organisms | |
| How does solar radiation shape climate? | angle that sun strikes Earth influences different climates | increased solar energy at equator + surrounding tropical regions promotes photosynthesis-> increases productivity in plants -> more biomass -> consumers depend on productivity of producers | |
| How wind currents affect climate | Earth has 6 convection cells -> warm, moist air rises + cool, dry air sinks -> generally consistent wind patterns -> prevailing winds - usually blow from a consistent direction in a given location | when cool air from polar regions collides with warm air moving north, precipitation results in temperate regions | |
| How water currents affect climate | Rotation of Earth, differences in water temp b/w poles + tropics, + directions of prevailing winds contribute to the formation of ocean currents | -w/o the warming effect of the water carried by currents such as Gulf Stream, climates around the world would be much different - North: oceans clockwise, South counterclockwise | |
| Biomes (What they are) | categorized based on unique climatic + ecological features of each such region | Terrestrial (land) + Aquatic (water) | |
| Terrestrial Biomes | location determined by climate -> effects of temperature + moisture on different species cause biomes to be found under consistent conditions | extent + distribution is strongly influenced by humans | |
| Tundra | frozen 10 months/yr, receives less precipitation than many deserts | 25 % of Earth's land -> trees scarce -> dominated by low-growing plants: grasses, sedges, moss, + lichens | permafrost - permanently frozen solid soil found below surface layers of tundra |
| Zebra Mussels | Invasion into the great lakes and North Am. is example of the impact humans have on the biosphere | ||
| How major features of Earth's surface shape climate | large bodies of water absorb + release heat more slowly -> creating a milder climate | mountains produce a rain shadow effect -> little precipitation falls on the side of the mountain that faces away from prevailing winds | |
| Boreal Forest | largest terrestrial biome, sub-Arctic landmass (b/c immediately south of tundra) | soil is thin + nutrient poor, rainfall is low -> plant diversity is low + conifers dominate vegetation | ex: Canada |
| Temperate Deciduous Forests | occur in regions w/ a distinct winter that lasts 4-5 months + precipitation is evenly distributed th/out year | greater species diversity (plants + animals) than tundra/boreal | deciduous trees are dominant vegetation |
| Grassland | found in temperate + tropical latitiudes | receive 25 - 100 cm of precipitation annually | soils in some are exceptionally deep + fertile -> therefore most have been converted to agriculture |
| Chaparral | shrub-land biome characterized by cool, rainy winters + hot, dry summers (ex: California) | dominated by dense growths of scrub oak + other drought-resistant plants | soil is poor + most species are adapted to hot, dry conditions |
| Desert | 1/3 of land surface, defined by its lack of precipitation | air lacks moisture + cannot moderate daily temperature fluctuations | plants have small leaves + can produce enormously long tap-roots -> majority of animal species are nocturnal |
| Tropical Forest | warm temperatures + about 12 hrs of daylight yr round -> abundant sunshine + moisture makes it most biodiverse biome | home to 50% of plant + animal species | more than half of the original tropical rainforest lost to logging + agriculture |
| Aquatic Biomes | cover about 75% of Earth's surface | salt content, water temperature, water depth, + speed of water flow are defining characteristics | Freshwater + Marine |
| How are aquatic biomes influenced by terrestrial biomes + climate? | water drains from terrestrial into aquatic through rivers + streams, which carry nutrients into the ocean | also influenced by worldwide events like El Nino | El Nino, (10 or so yr cycle) warm water flow changes, affects world wide like tornadoes, excess drought, etc |
| How are aquatic biomes influenced by human activity? | Wetlands + estuaries are destroyed by human development OR are negatively affected by anthropogenic pollution | also suffers when humans modify/destroy the terrestrial biomes they occupy | |
| Lakes | Standing bodies of water that are surrounded by land + are at least 2 hectares (5 acres) in size | the primary productivity of a lake + the abundance + distribution of its life forms are strongly influenced by nutrient concentrations, water depth, + the extent to which the lake water is mixed | |
| Rivers | bodies of freshwater whose physical characteristics tend to change along their length | move continuously in a single direction | |
| Wetlands | characterized by standing water shallow enough that rooted plants emerge above the water surface | Bogs are stagnant wetlands whose productivity + species diversity is low | marshes + swamps are highly productive wetlands |
| Estuary | region where a river empties into the sea + is the shallowest marine ecosystem | abundance + diversity of life make them one of the most productive ecosystems on our planet | marshes + swamps are highly productive wetlands |
| Coastal Region | underwater that stretches from the shoreline to the edge of the continental shelf | also highly productive | |
| Estuary | region where a river empties into the sea + is the shallowest marine ecosystem | abundance + diversity of life make them one of the most productive ecosystems on our planet | |
| Intertidal Zone | part of the coast that is closest to shore | extends from the highest tide mark to the lowest tide mark | |
| Coastal Region | underwater that stretches from the shoreline to the edge of the continental shelf | also highly productive | |
| Coastal Benthic Zone | may lie as deep as 200 m (656 ft) below the water surface | relatively stable habitat + is rich in sediments containing dead + decaying organic remains | benthic zone is the seabed floor in any of the underwater zones |
| Intertidal Zone | part of the coast that is closest to shore | extends from the highest tide mark to the lowest tide mark | |
| Oceanic Region | begins about 40 miles offshore | relatively nutrient-poor | |
| Abyssal Zone | begins where the continental shelf ends + the sea floor drops to a depth of approx 6000 m (about 20,000 ft) | ||
| How can invasive mussels harm ecosystems? | An introduced species can become a major pest in a new environment (invasive species) | Eurasian zebra mussel displaced native mussels in great lakes | also stripped away most of the planktonic producers that other animals eat |
| CH 22: Easter Island | once home to diverse group of species, now a barren grassland | example of what happens when humans use more resources than the biosphere | |
| Population Ecology | the study of the number of organisms in a particular place | essential for solving real-world problems (protecting endangered species or controlling pest species) | |
| What is a population? | a group of interacting individual of a single species located w/i a particular area | Population size (N) refers to total number of individuals in the population | Population density refers to the number of individuals per unit of area |
| What are changes in population size dependent on? | birth + death rates and immigration + emigration rates | all are affected by the environment | ex: Monarch butterflies - migrate to warmer temperatures for winter |
| Exponential Growth | rapid population growth that occurs w/ increases by a constant proportion over time | doubling time (to reach 2N) can be used as a measure of population growth | limited by resources + not seen under natural conditions |
| How is growth limited? | Habitat is an environment in which an organism lives + can limit population growth (By space + nutrients) | Ex: Reindeer introduced to Island in Alaska, population rose rapidly then crashed due to overgrazing (J shaped) | |
| Logistic Growth | an S shaped curve | considers change in growth rate as resouces become limited | Ex: Willow trees |
| Carrying Capacity | the maximum population size that can be sustained | @ cappacity, growth rate = 0 | Ex: Paramecium Caudatum |
| Density Dependent | change with population density | birth + death rates (growth limiting) | Ex: seeds reproduced/planted |
| Density Independent | factors not related to the density of the population | Ex: weather, natural disasters, environmental pollutants | |
| Pattern of Population Growth | J Shaped patterns indicate rapid population growth, which continues until all resources are depleted | S Shaped pattern indicates rate of growth slows as population nears carrying capacity | population cycle shows 2+ species change together because they are influenced by the (lynx + hare) |
| Irregular Fluctuations | Populations change in size over time (spastically - chance) | populations of same species may experience different patterns of growth | |
| Biomagnification | concentrations of PCB are integrated into fats of smaller unit of food web | as other members higher in the food web eat the fats of smaller units, due to longevity of life, concentrations double each cycle | ex: phytoplankton -> zooplankton -> crustaceans -> minnows -> trout -> osprey |
| CH 23: Toxoplasma Gondii | single celled parasite, most often contracted from raw meat, alter brain activity | often found in mice, makes them unafraid of cats which is then passed onto cats | |
| Ecological Community | an association of different species that live in the same area | greatly vary in size + complexity + characterized by their diversity | Diversity has 2 components: species richness + relative species abundance |
| Species Richness | the total number of species in an area | ||
| Relative Species Abundance | how common individuals of a species are compared to others | Ex: Same species of Trees in different communities | |
| Interactions Among Species | have huge effects on natural communities | Mutualism, Commensalism, Exploitation, Competition | |
| Mutualism (Symbiosis) | both species benefit, therefore increasing survival + reproduction | evolves when benefits of interaction outweighs the cost for both species | Types: Gut Inhabitant, Behavioral, Seed Dispersal, Pollinator |
| Behavioral | Goby + Shrimp | Shrimp keeps 1 antenna on goby, sudden movements alert shrimp to danger | |
| Gut Inhabitant | Fruit Trees -> animal ingestion | ||
| Seed Dispersal | Yucca Plants -> yucca moths | ||
| Pollinator | Bees/plants | ||
| How can species abundance be affected by mutualism? | by having indirect effects on species not a part of mutualism | ex: Coral symbiosis | Corals provide protection from predators, clear water, nitrogen + phosphorous + Zooxathellae provide energy + 90% of energy requirements |
| Commensalism | a relationship where 1 partner benefits while the other is neither helped or harmed | Ex: Barnacles + whales | |
| Exploitation | a variety of interactions when 1 species benefits, while the other is harmed | 3 categories: herbivores (plants/plant parts), predators (kill other species for food), parasites (consumers that live in or on organisms they eat) | consumers caused many species to evolve elaborate strategies to avoid being consumed |
| Induced Defenses | responses that are stimulated by an attack from herbivores | Ex: Cactus - Cactus Spines | Ex: Camouflage |
| Warning Coloration | used by prey to warn potential predators that they are heavily defended | Ex: Monarch Butterfly or poison dart frog or coral snake | |
| Mimicry | type of adaption in which a species imitates the appearance of something unappealing to its would be predator | Ex Viceroy Butterfly mimics Monarch, Scarlet King Snake mimics Coral Snake | |
| Co-Evolution | 2 species that interact trigger evolutionary change | consequence of their interactions | "one upping each other" |
| How can behaviors of organisms be altered as a result of exploitation from consumers? | animals who live/feed in groups probably evolved as a result due to predation | parasites cause behaviors in host organisms that benefit parasite | |
| What is a possible result of exploitation? | can drive organisms to extinction -> once exploited is extinct, exploiter must find new food source or become extinct | ||
| Competition | interspecific is likely when 2 species share an important resource that's limited | when 2+ species compete, each have a negative effect on each other b/c each uses resources needed by its competitor | important in natural selection + can limit the distribution/abundance of species competing |
| Ecological Niche | the sum total of the conditions + resources a population needs in order to survive + reproduce | ||
| Competitive Exclusion | occurs when 1 species uses all the resources needed by another + results in extinction | ||
| Interference Competition | 1 organism directly excludes another from use of a resource | "out eats" | |
| Exploitative Competition | species indirectly compete for a shared resource | each reduces the amount of resource available to the other | |
| Niche Partitioning | occurs when natural selection leads competing organisms to use their common niche in a more limited way as a method of reducing competition | Ex: barnacles - Semibalanus feeds in lower zone while Chtamalus feeds in higher portions of shoreline | |
| Character Displacement | occurs when intense competition b/w species causes them to evolve differently over time | Ex: Darwin's Finches (beaks) | |
| How do species interactions shape communities? | human actions + natural causes affect a species' chances of survival | any changes in species diversity in a community will have a ripple effect | |
| Food Chain | a linear sequence of who eats whom in a community | ||
| Food Web | made up of interconnected + overlapping food chains | illustrates movement of energy + nutrients th/out a community | Foundations consist of producers (plants + phytoplankton) |
| Consumers | organisms that obtain energy by eating all or parts of other organisms or their remains | Primary eat producers, secondary eat primary | secondary can be extended to tertiary + quaternary |
| Keystone Species | can include any producer or consumer of relatively low abundance that has a large influence on its community | usually only noticed when they are removed or disappear from an ecosystem | Ex: Sea star, sea urchins -> otters |
| Mature Communities | species composition remains stable over a long period of time | unlikely due to disturbances such as fires or windstorms | |
| Succession | process by which species in a community are replaced over time | Primary occurs in a newly created habitat - 1st species to colonize may alter habitat in ways that cause later species to thrive or fail | Secondary is the process by which state that existed before a disturbance is regained |
| How can climate affect community changes? | Change in global climate causes slow but dramatic changes in the location + diversity of plant + animal species | Human activities accelerate natural changes in global climate | Continents move -> climates change -> large changes in communities |
| How do humans affect community structure? | Can alter the frequency of a natural form of disturbance | Some communities can reassemble, but species sizes + abundance are different | Long term damages (from logging or overgrazing) can permanently alter |
| CH 24: Oil Spill in 2010 | Drilling rig exploded, 5 billion barrels of crude oil spilled into gulf of Mexico | stretched 22 miles under ocean's surface | damage to Gulf ecosystem similar to long term effects from oil spill in Alaska in 1989 |
| Ecosystem Ecology | The study of how energy + materials are used in natural systems | ||
| How do Ecosystems function? | defined by means through which energy is acquired by biotic community | energy flows in only 1 direction through ecosystems | @ each step, a portion of energy captured by producers is lost as metabolic heat |
| Nutrients | required chemical elements + are largely recycled b/w organisms + the physical environment | finite amount are absorbed by producers, cycled among consumers, + returned to environment | |
| Ecosystem Processes | physical, chemical, + biological processes that link the biotic + abiotic worlds in an ecosystem | ||
| Carbon Cycle | driven by photosynthesis + respiration | ||
| Nitrogen Fixation | turning gas to solid | carried out by certain prokaryotes | Ex: Nitrogen found in soil + water |
| Nitrogen | Goes into environment through lightning | good spread out, bad all piled together | |
| Sulfur | 95% from ocean sea spray | cycles through terrestrial + aquatic systems quickly | |
| Phosphorous | only sedimentary cycle - > large impact on NPP | eventually deposited to the sediment on the ocean floor | |
| Eutrophication | overfeeding nutrients into bodies of water from farmland runoff | causes algae to be more abundant -> increase in NPP -> decrease/elimination of fish + other animals | |
| How do human activities alter nutrient cycles? | Acid rain - result from burning fossil fuel | reduced fish populations + damaged acres of forests | |
| CH 25: Decrease of Phytoplankton | global population has decreased by 40% since 1950s | warmer temperatures, decrease in phytoplankton, polar bears are struggling for survival | due to expanding human population |
| Global Change | evidenced by decline in biodiversity | pollution has altered ecosystems | climate change largely caused by humans |
| Land Transformation | physical + biotic changes to land surface | destruction of habitat for resource use, agriculture, urban growth | |
| Water Transformation | physical + biotic changes people make to the waters | ||
| Examples of Transformation | aerial photos, satellite data, changing urban boundaries, destruction of natural habitats | destruction of rainforests, conversion from grasslands to cropland | urban development, sewage, nutrient runoff, pollution, + overfishing -> water |
| Bioaccumulation | chemicals released can accumulate in an organism at concentrations higher than the abiotic environment | ||
| Persistent Organic Pollutants (POPs) | long lived organic molecules that bioaccumulate + can have harmful effects | ||
| Change in Biosphere: Pollutants | CFC caused a decrease in ozone layer + contributed to ozone hole above Antarctica | worldwide response -> many countries banned CFCs | |
| Rise in Nutrients | Nitrogen - grasses are eliminated by most resilient | Carbon Dioxide levels contribute to global warming, risen significantly due to burning of fossil fuels, logging/fires, + industrial processes | Rise in CO2 means more photosynthesis from plants |
| Greenhouse Effect | gases trap + absorb heat -> temperatures rise | ||
| Consequences of Climate Change | Decline of Arctic sea ice, sea levels rising, more acidic oceans, increased sever weather | many species endangered (ex: coral reefs: 1/3 destroyed from bleaching, pollution, physical damage from storms) | |
| Keys to minimizing Climate Change | reduced use of fossil fuels | increased energy efficiency | increased reliance on renewable energy |