Biology Unit 12: Ecology

What is the difference between an ecosystem and environment?

-ecosystem is a much smaller scale than a environment

What is an abiotic factor?

-the nonliving factors in the environment (light, water, pH, salinity, etc.)

What is population density?

-the number of organisms per unit of area -there are different types of organism clusters -some live close together, some live in random clusters, some live individually

What is eutrophication?

-a process the deposition of nutrients such as nitrogen, phosphate, and initial oxygen increase cause there to be lots of algae in the water

What is ammonification?

-ammonification is the process in which nitrogen in the remain of dead organisms is broken down and released as ammonia

What is a habitat?

-an area where an organism lives

What is an organism?

-an individual living thing -ex) a striped fish

What is a decomposer?

-an organism that breaks down dead organisms by secreting digestive enzymes -ex) bacteria, fungi

What is another name for a heterotroph?

-another name for a heterotroph is a consumer

What is another name for plants?

-another name for plants is photoautotrophs

What are density independent factors?

-any factor that does not depend on the number of organisms in a population per unit of area -usually abiotic and a natural disaster -ex) tornado, hurricane, extreme cold and hot weather -ex) pollution, building a dam, introduction of invasive species -all these are not affected by population density, but they do affect population density

What is energy transfer?

-as energy moves along from 1 trophic level to the next, not all of the energy is transferred -only 10% of the energy from 1 trophic level gets passed to the next -most of the energy is lost as heat -other energy is used for normal cellular processes -this is different for materials that take a long time to break down (ex. toxins)

How does eutrophication affect organisms?

-as phosphate and nitrogen builds up in the body of water via agricultural runoffs and detergent from residential areas, it will begin to form algae -the algae takes up a lot of the sunlight at the top of the body of water, so the algae underneath that top layer will die and later decompose and fall to the bottom of the lake -this decomposition will take up lots of oxygen, thus slowly depleting the oxygen supply of that body of water -large fish who require lots of oxygen will die and decompose-this takes up oxygen-little fish will not have any oxygen left-they will die and decompose-the entire lake fills up with this matter-it becomes very shallow -some forests are created like this

What is biological accumulation?

-at higher trophic levels, toxins go up and energy goes down -toxins take a longer amount of time to get out of your system/break down -ex) mercury in fish -ex) DDT, an insecticide, killed many birds, it didn't affect bugs that much, but it affected birds because birds ate many of those bugs and as the insecticide got passed along the food chain, the amount of energy passed along decreased

What is an ecosystem?

-biological community and all of the biotic and abiotic factors that affect it ex) just one coral reef off coast of Florida (temp. of water, salinity, sunlight, pH, etc.)

What are the forms of atmospheric carbon?

-carbon monoxide -carbon dioxide -chloroflourocarbons

What is exponential growth?

-characterized by abundance of resources and no limitation factors

What is the deciduous forest biome?

-characterized by dense trails of deciduous trees -deciduous means "leaf-bearing" -found in areas that have sufficient moisture to support the growth of very large trees -they are more open than rainforests and their plant life is not as tall -leaves change color and they fall off trees because the trees choke off the leaves after they have died and are doing nothing but taking up resources -the trees are basically dead during the winter -leaves change colors throughout the seasons -almost ll of the original deciduous forests in US have been destroyed by logging and land clearing for Urban development -animals hibernate during winter months

What is the chaparral biome?

-characterized by dense, spiny, evergreen shrubs -fires are caused by dry sticks, but plants have made adaptations to survive the fires -there are fire-resistant roots of plants where they store sugar under high heat-they germinate soon after, and then they release their seeds, thus the soil around them becomes fertile -usually have mild, rainy winters and long hot summers -plant life has adapted and become dependent on periodic fires -brushfires are extremely common in these regions -there is a dry and wet season as well as low lying brushes

What is logistic growth?

-characterized by limited resources that eventually cause the population to reach a carrying capacity -starts as an exponential graph but then it begins to level out

What is the tundra biome?

-characterized by permafrost (permanently frozen soil), cold temperatures, and high winds -these are drastic conditions -these abiotic factors are responsible for the absence of all tall trees and other tall plants in the area -covers the arctic and amounts for 20% of the Earth's land surface -animals have adapted their own ways of survival -ex) during the winter, the rabbit's fur is white so it can blend into the whiteness, but during the summer, the fur is brown so it can confused the predator into thinking that the rabbit is dirt

What is the desert biome?

-characterized by sparse rainfall (less than 30 cm/year) -some deserts have sand, some have ice (Siberian desert) -some will have soil surface temperatures above 60 degrees celsius during the day -these harsh conditions require the animals to make adaptations (sand gets really hot-kangaroos dig to find cooler ground)

What has the biggest affect on a biome?

-climate and latitude

What is symbiosis?

-close interactions/relationship between organisms that live close/intimately to one another

What is secondary succession?

-ecosystems that supported life before, but were somehow decimated (fire, flood, logging, etc.) -ex) there was a fire in a forest that burned down part of the forest and SOME organisms were killed-that area is completely bare-some organisms fled, but to nearby areas -soon enough, the plants surrounding the charred area will begin to germinate and their seeds will distribute themselves across the burnt land farther and farther until the entire land is covered in them-soon enough, plants begin to grow again-the dead organisms there contribute nutrients and organic matter to the soil so that plants can grow there-food is abundant and competition is low-organisms will come there and colonize-population comes back again -these have no need for pioneer organisms -they take lesser time to rebuild because they already have soil

What makes up an environment?

-everything that surrounds us (living/nonliving factors)

What are density dependent factors?

-factors that do depend on the number of organisms of a population per unit of area -usually biotic factors -ex) predation, competition (many organisms in one area, lots of competition for resources and food), parasitism, diseases (many organisms in one area, hot spot for spreading of diseases)

What are food chains?

-food chains that are simple models that show how energy can flow through an ecosystem

What are food webs?

-food webs are models that represent the many interconnected food chains and pathways in which energy flows through a group of organisms -ex) hawke, snake, mouse, seed, and rabbit

What is acid rain?

-form of air pollution that produces far-ranging effects

What is the savanna biome?

-grasses and scattered trees are the dominant plant life -fire is an extremely important abiotic factor due to the dry grass that is there -the growth of grasses and small plants during the rainy seasons provide a rich source of food for animals because there aren't many resources other than that -during the seasonal drought, the large herds of animals often migrate to greener pastures (water holes)

What is a community?

-group of different population of species that interact with one another/live in same area at the same time -ex) living things in the coral reef off coast of Florida: fish, coral, marine plants

What is a biome?

-group of ecosystems that have similar climates/communities (groups of organisms interacting with one another) -ex) coral reef off coast of Florida

What are omnivores?

-heterotrophs that consume both autotrophs and heterotrophs -ex) humans

What are carnivores?

-heterotrophs that only eat other heterotrophs

What are herbivores?

-heterotrophs that only eat plants

What is the nitrogen? How much of the Earth's atmosphere is made from it? Is it usable?

-important for plants and proteins -78% of the Earth's atmosphere is made from nitrogen gas -most of this isn't usable

What biomes dominate the lowland areas which are characterized by low rainfall and prolonged dry season?

-in lowland areas (characterized by low rainfall/prolonged dry season) the tropical dry forests dominate -plant life is dominated by thorny shrubs and trees -regions are distinctly dry and tropical deciduous trees are common

What is a population?

-individual organisms of a single species that share the same area at the same time and they also have the same gene pool -ex) school of fish living in just one coral reef off coast of Florida

Why is acid rain harmful?

-it falls far away from its original pollution source -it is more acidic than normal rainwater -plants are hurt above/below ground because this acidic rain washes away nutrients from their roots due to the rain molecule's polarity -bodies of water are affected because they have established a pH that they have to maintain, but with this rain, the pH is affected and therefore, this affects the organisms in the water-they die off

What is the tropical rainforest biome?

-it has very pronounced vertical stratification (floor, brush, canopy, emerging) -the canopy is often overgrown and closed, blocking out most light from reaching the forest floor and since there is so much growth of the trees, there is lots of competition amongst the plants to get the most sunlight -lots of bio-diversity in terms of species because there is so much food on the trees -rainfall will be the main factor in determining the vegetation growth of that region -have wet and dry season

What is contour plowing?

-it is a method in which we create indents/bumps in the soil so that when it rains, the water has a hard time carrying the soil away

What is terracing?

-it is a method where if a farm is on a hill, the farmer will add "steps" or platforms to the side of the hill so that when rain comes, it will pool at the top of a step before running down so that it isn't able to carry that much soil with it -it slows down the rapid runoff of water

What is biological magnification?

-it is the increase in concentration of toxic substances in organisms as levels increase

What does the ozone layer do?

-it protects us from the sun

What is population size determined by?

-limiting factors

What is a biotic factor?

-living factors in the environment (fish, humans, plants, etc.)

What are the two types of aquatic biomes?

-marine biomes and freshwater biomes

What is minimal tillage?

-method in which we attempt to stop loosening the soil to reduce the chances of soil erosion/dust storms

What is carbon dioxide?

-molecule released through the process of cellular respiration

What happens with energy transfer within plants?

-most of the energy goes to maintenance/growth of plants

What is true about most parasites?

-most parasites do not want to kill the host

What is primary succession?

-newly formed area, no life has ever existed there before -volcanic rock from volcano eruption is the only thing that is left there -establishment of a community in an area of exposed rock that have no soil -after lichens attach to rocks and break them down, we wait for birds to drop some form of organic material to fertilize the soil so that plants can grow there -plants begin to grow and animals (birds) passing by notice the food and lack of competition-colonize there-other organisms come-island becomes stabilized and properly populated -climax community is made

What is nitrification?

-nitrification is when soil bacteria convert the ammonium into nitrites which are then converted to nitrates -bacteria helps with this process because it is a mutual relationship between bacteria and plants (bacteria gets sugars and plants can't live without nitrogen)

What is the nitrogen cycle?

-nitrogen to ammonia -ammonification, nitrification, dentrification

What are oligotrophic lakes?

-nutrient poor -oxygen rich -found at high altitudes -usually younger than eutrophic lakes

What are eutrophic lakes?

-nutrient rich (algae) -oxygen poor -found at low altitudes -usually older than oligotrophic lakes -greener than oligotrophic lakes

What are the two types of lakes/ponds?

-oligotrophic lakes -eutrophic lakes

What is chloroflourocarbons?

-once used as refrigerants -deplete the ozone layer and exposes the Earth to UV radiation -ex) CFCs accumulated over Australia-destroyed the ozone layer

How much energy does an organism keep for itself after it eats food? What is an example?

-organisms only keep 10% of the energy they consume for maintenance -ex) sun gives 1,000 joules of energy to a seed, the seed keeps 100 joules, a mouse that eats it gets 10 joules, a snake that eats the mouse gets 1 joule, and the hawk that eats the snake gets .1 joule

What are detritivores?

-organisms that eat parts of dead matter in order to return the nutrients to the environment -ex) maggots, worms

What are lichens?

-pioneer organisms that grow on rocks and they secrete powerful digestive enzymes that can split the rock they are on further and further until it becomes pebbles -this takes a VERY long time -algae+fungus

What are some adaptations that have been made in the coniferous forest biome?

-plants have had to survive in these forests in both the winter and the summer -there are specific adaptations that would allow conebearing trees to see -in the winter: the cone shape of the tree allows the snow that falls on it to fall right off without damaging the beaches (the branches are really limber, so they just bounce back) -in the summer: pine needles reduce the amount of water due to their large layer of cutin

What is the pattern is we noticed between prey and predator?

-prey and predator increase and decrease with one another

What are the two types of successions?

-primary and secondary succession

What is commensalism?

-relationship between organisms when one benefits and the other one isn't affected -+/0 -ex) pilot fish: swim underneath sharks, whenever sharks feed, whatever food is left, pilot fish can eat, fish benefit, the shark doesn't really care about their presence, he isn't affected

What is parasitism?

-relationship in which 1 organism benefits at the expense of another, it takes resources away from that organism -+/-

What is mutualism?

-relationship where both organisms benefit -+/+ relationship -ex) Ecoli bacteria: live in our intestines and provide vitamins that we need that we could not get without them, and in turn, they get a nice place to live

What is carbon monoxide?

-released by the burning of fossil fuels -has a higher affinity for hemoglobin (when it is released, it will attach to your hemoglobin on your red blood cells and then you will be transporting that instead of oxygen-you are suffocating yourself and your brain-leads to severe brain damage -if you are stuck in a room and you pass out due to the gas because it made you sleepy, then you are dead -scientists and gas companies have added scent to the gas and created detectors so that you can tell this is a poisonous gas

What could cause logistic graphs to level out? What is an example?

-resources begin to run out and therefore there is increased competition amongst the organisms to survive-some die off -ex) deer population: deers experienced a very successful year in reproduction, their offspring were so abundant, but eventually the population began to decrease drastically because those deers had eaten all of the grass on the plateau and now they were starving to death

What have we noticed about species through food webs/chains?

-species cannot rely on one food source -species feed on other populations when the one they were accustomed to eating has died down and they wait for it to start up again so they can feed on it again

What is a climax community?

-stable and mature community that results when there is little change to the composition of organisms

What kinds of waters are prone to eutrophication?

-still waters -bodies of water that are near farms and residential homes where there can be a run-off of nutrients and nitrogen and phosphate which can lead to out-of control algae growth

What is predation?

-the act of one organism consuming the other -+/- relationship

How do energy and food play a role in where an organism will live?

-the availability of food will be a determining factor where organisms live -the amount of energy available also has to be considered -energy is stored in food that organisms consume

What is transpiration?

-the loss of water through the pores in the stomata of the plants (helps with capillary action) -when plants get hot, the water leaves them and cools the air around them, when the cool breeze blows, the water goes away, thus there is more transpiration

What is carrying capacity?

-the maximum number of organisms in a species that a particular environment can sustain for long term

What are some evolutionary adaptations that some creatures have made?

-the pleated structure of cacti enables them to expand when they absorb water so they can absorb as much as possible -they also have thorns so that other animals don't come and take their water -shallow root system of plants: when there is a flash flood or lots of rainfall, the rain goes straight to the roots without being lost -some species of desert mice never drink, they only get their water from the metabolic breakdown of the seeds they eat (they get metabolic water) -desert plants go through CAM photosynthesis so that they conserve water in an arid environment so at night, they open their stomata and less water leave, they store CO2, and during the day they close their stomata to save water and they create the sugar then -some plants have poison and spikes to keep other animals from feeding on them -most animals are nocturnal (only come out when it is cool)

What is nitrogen fixation?

-the process in which special bacteria and algae convert nitrogen gas into nitrogen compounds, like ammonia -this is one method how the earliest organisms got nitrogen -animals make their proteins using nitrogen and so do plants-animals that eat plants get the proteins and nitrogen and this continues throughout the trophic levels -this can also be done by lighting and UV radiation

What is a niche of an organism?

-the role of an organism within its environment (where it lives, what it does, who eats it, who it eats, etc.)

What is ecological succession?

-the way in which the environment is constantly changing -change in an ecosystem that happens when one community replaces another as a result of changing biotic/abiotic factors -starts off with short, small plants (moss) -ends with large plants with long lifespans

What is the greenhouse effect?

-there is a build-up of CO2 in the atmosphere -this traps heat -this contributes to the increase in temperature, leaving scientists concerned -the temperatures of Earth are no longer stable -some pollutants also cause the ozone layer to deplete, therefore, it can no longer protect us from harmful UV radiation

Is there a limit to the level of food chains?

-there is a limit to food chain levels due to energy loss -usually only a third or fourth level

What are aquatic biomes?

-they account for the largest part of the biosphere in terms of area

What are invasive species?

-they are a nonnative species that are introduced into a new environment -somehow they become the dominant species and lead to local extinction of the native species -this is because they have no natural predators and they can outcompete for food, shelter, and resources -sometimes they are purposefully introduced, sometimes on accident, etc. -not every species is invasive, some just drive others to local extinction -ex) zebra mussels in Australia: scientists introduced this species to a bay, but they began to colonize very quickly and they soon took over the entire bay and killed off many native organisms -ex) cane toad: scientists introduced cane toads to the environment, thinking they would be able to kill off the beetles, but they didn't realize that it killed off the wrong species of beetles and soon those toads were killing off many native species

What is another name for autotrophs?

-they are also called producers

What are coniferous forests?

-they are characterized by coniferous trees, meaning that they are "cone-bearing" -ex) acorns, pine, spruce, fir, hemlock -warm, moist air support these areas (coming from the Pacific Ocean) -the norther coniferous forest is the largest terrestrial biome on Earth (taiga) -there is heavy snowfall during the winter

What are trophic levels?

-they are feeding steps -they are visualized in food chains/webs

Where are chemoautotrophs found?

-they are found in deepsea vents, small underwater volcanoes with nutrients

What are abiotic factors important in determining?

-they are important in determining why a particular terrestrial biome is located in a certain area

What is the temperate grassland biome?

-they are maintained by seasonal droughts, occasional fires, and large mammal grazing -there are no large plants -all these prevent growth of woody shrubs and trees -at one point, this biome covered most of north america -the soil is deep and rich in nutrients -the land is extremely fertile -they were great of agricultural purposes like growing crops -very little prairie still exists today

What are autotrophs?

-they are organisms that collect energy to produce their own food

What are heterotrophs?

-they are organisms that get their energy from consuming other organisms

What are chemoautotrophs?

-they are organisms that use chemicals in their environment to make their own food

What are humans compared to other species?

-they are the dominant species

How to legumes help soil?

-they are used in crop rotation to return nutrients and nitrogen to the soil

What are biomes usually named for?

-they are usually named for major physical climate features and for the major vegetation found there -also characterized by microorganisms, fungi, and animals adapted to that environment over time to survive there

What do biotic and abiotic factors have in common?

-they both have an affect on the living organisms there in that ecosystem

What are limiting factors?

-they determine population size -they are any factor that restricts the numbers, reproduction, or distribution of organisms -these are resources that if they run out they will affect the population in a negative way -ex) water, food, shelter, etc.

What are freshwater biomes?

-they generally have less than 1% of salinity in the water -closely linked to the soils and biotic components of terrestrial biomes though which they pass -they are usually characterized by the patterns and speed of the water flow and the climate in which they are located -there are two types of freshwater biomes: standing and flowing bodies of water -ex) lakes and ponds (standing) -ex) streams and river (flowing) -ex) aquatities (bodies of water underground

What have humans done to the population of pests?

-they have actually increased the number of agricultural pests by planting large numbers of the same crop in one area -just because that one crop grows well on a particular soil, does not make it a good idea to grow many amounts of it there because then, we are putting pressure on the pests to evolve and specialize in eating that crop

What are some ways towns have attempted to reduce the chances of eutrophication happening?

-they have attempted to skim the surfaces of the bodies of water to clear them of algae -they have created water fountains to regulate the water and the nutrients so they do not build up in one place -they clean and scoop up any decomposed matter at the bottom of these bodies of water

In what ways have humans attempted to counter the pest situation?

-they have tried autocidal pest control, where they introduce sterile males into the population -the males will mate with the females and some eggs may be laid, but they are not fertile so there are little/no offspring -this is effective and eco-friendly

What are plants? How are they important?

-they use energy from sunlight to make their own food -they are an original source of energy

What are the parts of the water cycle?

-transpiration, evaporation, and condensation

What are marine biomes?

-usually are salt water -usually have salt concentrations up to 3% -cover about 73% of Earth's surface -the evaporation of seawater provides most of the planet's rainfall -ocean temperatures have a major impact on world climate and wind patterns and air pressure systems -marine algae and photosynthetic bacteria supply a large portion of the world's oxygen and in dong so they also consume huge amounts of atmospheric carbon dioxide that we release -these bacteria and algae undergo photosynthesis and since there are many of them, they produce a lot of oxygen

What are the three nutrient cycles?

-water, carbon, and nitrogen cycles

What do humans have the power to do?

-we are problem-solvers, we have the potential to increase the carrying capacity

What are some alternative power sources?

-we have to reduce our dependency on our current power sources -nuclear: very efficient and powerful, it can give us lots of energy, and we have been working on reducing the amount of risk that comes with using it, but what if there is a flood/tsunami/earthquake? There are some things that we cannot control and the radioactive waste that comes from this energy source has no where to go, we can't just dump it -wind: this is a great SUPPLEMENTAL power source, but the energy is not enough to run many things, but also, lots of big birds have hit these and died, and what about areas that don't get too much wind? It can't work everywhere -solar: great supplemental source, but again, what about places that don't get too much sunlight (Alaska), it can't work everywhere

What is the method we use to try to lessen our impact on soil?

-we have tried to use contour plowing, terracing, and minimal tilling/tillace

What is crop rotation?

-when farmers have 4 plots in their land (could be 3, as many as they want) and one year, they plant in three of them (1, 2, and 3, 4 is left behind), and then they rotate so that they use the one plot of land they didn't use last year (4 is used, as well as 2 and 3, 1 is not) and the cycle continues (the next year 2 will be skipped, 4, 3, and 1 are used) -method of replenishing the nutrients of the soil because farmers noticed that soon their crops began to decrease in number over the years when they plotted all of their land -they decided to try this where the plot they didn't use to farm they left scraps of food there for nutrients -this was discovered by accident

How is acid rain formed?

-when fossil fuels are burned, sulfur dioxide, carbon dioxide/monoxide are released into the atmosphere -sulfur dioxide mixes in with the rainwater to form acid rain

What is sublimation?

-when ice goes directly to water vapor by skipping the liquid water stage -ex) dry ice

What is dentrification?

-when nitrates convert back to nitrogen gas -nitrates are waste material, they have to turn back into something that can be re-used

What is parasitoidism?

-when the parasite lays eggs inside the host -ex) wasp species that lay eggs within caterpillars

What is endoparasitism?

-when the parasite lives inside the body of the host -ex) tapeworm, liver worms

What is ectoparasitism?

-when the parasite lives outside the body of the host -ex) leech, tick

How do organisms try to sustain their own population?

-when they notice that their resources run low, they begin to slow down their reproduction so that they don't overshoot the carrying capacity

What is evaporation?

-when water changes into water vapor -this causes rainfall -water turns into water vapor, goes into the sky, and then cools down

What is condensation?

-when water vapor changes to liquid water after cooling down -causes precipitation

What is deposition?

-when water vapor freezes directly into ice skipping the liquid water stage

What are the levels of ecological organizations?

biosphere, biome, ecosystems, communities, and population

What is a biosphere?

portion of Earth that supports life (habitable places on Earth)

What leads to the evolution of organisms?

the interactions amongst organisms lead to evolution of organisms

What is ecology?

the study of organisms and how they interact with their environment