exam 1 Flashcards
accuracy
correctness of measurements
precision
repeatability of results
scientific method
- Identify problem
- Form hypothesis
- Test it
- Interpret results-if hypothesis wrong, come up with new one
ind. variable
variable being changed
dependent variable
variable impacted by ind. variable (depends on it)
system
interdependent network – energy flows from one thing to another
state variables
store resources within systems
work together – sun creates photosynthesis for plant-bunny eats energy created by photosynthesis-fox eats bunny-fox decomposes-cycle restarts
positive feedback loop
increase in system variable–leads to further increases
negative feedback loop
suppresses change within system–keeps balance
feedback loops working together
fish tank – sunlight comes in, creates energy–fish eats food, processes energy from it, defecates–needs to replace that energy with more food (food-takes in oxygen, releases carbon dioxide)
elements
simple substances that can’t be broken down (96% of mass of living things – hydrogen, nitrogen, oxygen, carbon)
atoms
smallest particles that have element characteristics
compounds
substances made up of different types of atoms
molecule
two or more atoms joined together
chemical bonds
chemical energy holding atoms together within molecules
ionic bonds
atoms with opposite charges bond (na – negative bond, cl – positive bond)
covalent bonds
atoms bond sharing electrons (water – hydrogen slight positive charge, oxygen slight negative – water is cohesive)
kinetic energy
energy in moving objects (ex. energy in water going down waterfall)
potential energy
stored energy (ex. energy in water waiting to go down waterfall)
chemical energy
energy stored in food or fossil fuels
first law of thermodynamics
energy can be transformed, not created/destroyed (same as matter)
second law of thermodynamics
each energy transfer – less energy available. 10% of energy from source retained from level to level
photosynthesis
captures energy – light dependent reactions in chloroplasts of plant cells. 6 carbon dioxide + 6 water + light reaction = 6 glucose (C6, H12, O6) + 6 oxygen gas.
glucose – primary fuel for metabolic processes
cellular respiration
releases energy – splits hydrogen/carbon from glucose – combines them with oxygen, leads to carbon dioxide, water.
glucose + 6 oxygen = 6 water + 6 carbon dioxide + energy
animals get energy through cellular respiration – eat animals that already ate plants, get energy from that cellular respiration
trophic structure
feeding relationships among species in a community
trophic levels
producers (plants) primary consumers (rabbits eat plants) secondary consumers (foxes eat rabbits) tertiary consumers (eagle eats fox)
10% rule
10% of energy transferred from one trophic level to the next
biomagnification
toxin levels increase as toxin goes up trophic levels (bald eagles – DDT gets to them – eggs weren’t the right size/misshapen – issues with eggs hatching)
water cycle
cycle of water through earth. human impacts – global warming – water evaporates, less water to go around
carbon cycle
movement of carbon through the earth (human impacts – fossil fuels generates too much carbon for sinks to take in –excess carbon in air – global warming)
nitrogen cycle
nitrogen fertilizer – puts excess nitrogen in system. fertilizer goes into ocean – ingested by small organisms
natural selection
individuals with traits better suited for their environment pass on their traits to the next generation. leads to accumulation of desired traits over time
evolution
species change over generations while competing for resources. those who have better traits are better competitors
generalists
broad ecological niche – can tolerate many environmental factors
specialists
narrow niche – specific habitat requirements, less reproductive frequency, less resilient to environmental factors, only found in one habitat
selection pressure
favoring characteristics in individuals in a population – population shifts towards those over time
directional selection
one trait favored/one eliminated
stabilizing selection
narrowing range of trait
disruptive selection
traits diverge towards two extremes
competition
-/-. organisms compete for limited resources
predation
+/-. predator/prey relationship
co-evolution
species change together, adapt – flowers and pollinating organisms, etc.
mutualism
+/+. both organisms benefit
commensalism
+/neutral. one organism benefits, one organism gets no benefit or negative impact
parasitism
beneficial for one species, detrimental to host
disturbance
any force that disrupts established community. can be good and bad
intermediate disturbance hypothesis
communities with intermediate disturbances have more species than those with high/low disturbance rates
species richness
number of species in a community
species evenness
individual abundance rate per species
threats to biodiversity – hippo
Habitat destruction Invasive species Pollution Population Overharvesting
biodiversity hotspots
locations that contain 1,500 endemic species when totaled together
environmental science
systematic study of environment + our correct role in it
