APES Unit 3

closed system

all matter or energy in system stays within system

open system

matter or energy is lost from the system, most energy systems (constant input of solar energy)

inputs

matter or energy entering systems

outputs

matter or energy leaving systems

matter

anything that has mass and takes up space, usually in a closed system

energy

the ability to do , usually in open system

kinetic energy

energy of motion, includes heat and forms of electromagnetic radiation

heat

total kinetic energy from all moving atoms, ions, and molecules in a given substance

electromagnetic radiation

wave form of energy in which wavelength and frequency are inversely related

longer wavelength

lower energy

potential energy

stored by matter and potentially available for use, includes chemical bonds and chemical energy

biomass

chemical bonds in organic molecules are a form of potential energy, LIVING MATTER

first law of thermodynamic (law of conservation)

energy can be neither created nor destroyed in any chemical or physical process

second law of thermodynamics

when energy changes from one form to another, some of the useful energy is always degraded into a lower-quality, more dispersed, less useful energy

entropy

tendency of energy in a system ot lose the ability to do work and thereby increase the disorder of the system

aerobic respiration

involves oxygen, opposite reaction of photsynthesis (produce carbon dioxide)

anaerobic respiration or fermentation

dont use oxygen, break down glucose in the absense of oxygen, end products: methane, alcohol, hydrogen sulfide

primary productivity

the rate at which sunlight energy is fixed into chemical bond energy of organic compounds

gross primary productivity (GPP)

total amount of organic molecules produced by photosynthetic organisms

net primary productivity (NPP)

amount of organic molecules that are AVAILABLE to the rest of the organisms in an ecosystem AFTER producers have used some of the glucose they produced. (less than GPP)

atmosphere

outermost sphere, contains air and atmospheric gases

hydrosphere

consists of the Earth's water

lithosphere

earth's crust and upper mantle which surrounds the inner core and mantle

biosphere

area in which living and dead organisms complete natural cycles

food chain

sequence of organisms, each of which is a source of food for the next, determines how energy and nutrients move from one organism to another through an ecosystem

food web

more realistic than food chain, because in nature most organisms have more than one source of food and shows that all organisms in an ecosystem are interconnected

trophic level

feeding level assigned to each organism in an ecosystem (types of producers and consumers)

autotrophs

organisms such as plants that make their own food, first trophic level called primary producers

heterotrophs

cannot obtain energy directly from the sun, consumers

primary consumer

usually herbivores (plant-eaters), feed on primary producers

secondary consumer

often carnivores (meat-eaters), feed on herbivores

tertiary consumers

carnivores that feed on other carnivores

omnivores

feeding on both plants and animals, often very succesful because of their ability to obtain nutrients from diverse sources

decomposer

specialized organisms that recycle nutrients in ecosystems, usually bacteria or fungi

detritivores

insects or arthropods or other scavengers that feed on the wastes or dead bodies of other organisms

ecological efficiency

percentage of usable energy transferred as biomass from one trophic level to the next

matter recycling

closed system completed by decomposer that break down organic matter into inorganic nutrients that can be re-used by producers

water cycle

collects, purifies, distributes, and recycles the Earth's fixed supply of water, powered by energy from the sun and the force of gravity

carbon sinks

organisms and systems that remove carbon dioxide from the atmosphere and store it

rhizoids

commensalist structure of n-fixing bacteria and plant root nodules

fixation

atmospheric N2 is converted into ammonia, NH3 and ammonium, NH4+, by bacteria in soil/water

nitrification

ammonia and ammonium are converted first into nitrite and then into nitrate

assimilation

plant roots absorb ammonium ions and nitrate ions for use in making molecules such as DNA, amino acids, and proteins

denitrification

bacteria in waterlogged soils and swamps convert ammonia, ammonium, nitrate, and nitrite back into N2 and N2O; these gases are then released back into the atmosphere

ammonification

decomposing bacteria convert organic wastes into ammonia and ammonium

fossils

mineralized or petrified replicas of skeletons, bones, teeth, shells, leaves, seeds, or impressions of items left in rock

biological evolution

the description of how life on Earth changes over time

natural selection

some individuals in a population will possess traits that make them more likely to survive and reproduce

chemical evolution

organic molecules, polymers, and systems of chemical reactions formed the first cells

microevolutions

mutations+genetic recombination change gene frequency in a population

speciation

evolutionary changes causes members of the same species to no longer be able to interbreed

genetic variability

within a population, how many different genes for the same trait are present within a population

mutations

random changes in the structure or sequence of DNA in a cell that can be inherited by offspring

natural selection

occurs when some individuals in a population have genes that produce traits that increase their chances of survival in a particular environment, or when that environment chagnes

three conditions for biological evolution by natural selection:

1)must be enough genetic variability for a trait to exist 2) trait must be heritable 3) trait must lead to differential reproduction, enabling individuals with the trait to leave more offsprings thatn other members of the population

population genetics

the study of alleles or genetic traits in a population

Hardy-Weinberg Law

list of criteria that would have to happen for gene pool NOT to change "ideal population"
1) mating would be random 2) there would be no mutation 3) no immigration or emigration so # of gene stay constant 4) population would be large 5) all organisms have

directional selection

individuals at one end of the curve of the phenotype distribution have higher fitness than individuals in the middle or other end

stabilizing selection

when individuals near the center of the curve have higher fitness than individuals at the other end of the curve

disruptive selection

individuals at the upper and lower ends of the curve have higher fitness that those near the middle

adaptation

any heritable characteristic that enables an organism to survive through natural selection and reproduce better under prevailing environmental condition

morphological adaptation

specialized structures for habitat such as camouflage

physiological adaptation

specialized function such as venom

behavioral adaptation

migration such as the mimicry

pre-zygotic barriers

cause individuals to not be able to interbreed (before fertilization) such as physical differences, behavioral differences, timing of reproduction

post-zygotic barriers

cause individuals to not be able to interbreed after fertilization such as fertilized egg will not develope and lack of reproductive capacity in offspring

geographic isolation

a small group separated from the main population will rotate only a few genes

reproductive isolation

some species show a preference for a particular color, dance, or display

adaptive isolation

species move out of home range

convergence

different species in the same habitat develop similar characteristics

coevolution

adaptations based on dependence on another organism

hybridization

indiciduals of two distinct species crossbreed to produce a hybrid

horizontal gene transfer

exchange genes without sexual reproduction

backgroud extinction

relatively fixed amount of species that go extinct over certain periods of time due to natural, changing environmental conditions

mass extinction

significant rise in extinction rates above background level

mass depletion

extinction rates are higher than normal but not enough to classify as a mass extinction