Exam Data • 1 perfect score • 1st – 78, 5 failures, 1 over 100 • 2nd – 79, 5 failures • 3rd – 85, 2 failures, Highest score 107 • 4th – 89, 7 failures, Highest score 107 • 5th - 76, 7 failures • 7th – 74, 5 failures, 2 over 100
Bellwork: 10/19/2011 • Change 10% of your tank water if your water is clear, change 25% of your water if your water is cloudy • Clear off your filters if they are obstructed & check your filters incase they need to be replaced (turn off the filter before checking). • Make sure to scrub off the debris in the corners of your tank • Clean off the tank lids
How do we study environments? • Quadrant Studies: Tracking changes in a small section of the environment
How do we study environments? • Sampling: Only measuring a small, random part of an environment
Carbon Cycle • Carbon is found throughout the environment • Carbon is found in the atmosphere and in water as carbon dioxide (CO2) • Carbon is found in organisms as organic molecules, like glucose (sugars) and fats • Carbon is found buried in the ground as fossil fuels
Carbon Cycle • Carbon is cycled, or moves • Atmosphere: Carbon is in the form of CO2
Carbon Cycle 2) Producers: Use photosynthesis to make sugars from CO2 in the atmosphere (carbon is moved!)
Carbon Cycle 3) Consumers: Eat organic molecules and release CO2 into the atmosphere during respiration, or die and go into the soil
Carbon Cycle 4) Soil: decomposers break down organisms, releasing carbon into the atmosphere OR trapping it in the ground (fossils)
Carbon Cycle 5) Fossil Fuels: carbon from some dead organisms are trapped as fossil fuel until we burn it
Populations • Population: the number of organism from one species that live in a specific area • Examples: the human population in different cities, the squirrel population in a forest, the grass population in a meadow
Populations • Populations are affected by many resources. These include: • The amount of food available in an area • The amount of sunlight (if it is a plant population) • The amount of water • The competition for food/shelter • The predators in an area
Population Growth Graphs A: Slow growth as a population begins to grow Birth Rate > Death Rate
Population Growth Graphs B: Exponential growth as population grows rapidly Birth Rate > Death Rate
Population Growth Graphs C: Slow-down of growth as population maxes out its resources, like food, water, or light Birth Rate > Death Rate
Population Growth Graphs Birth Rate = Death Rate D: Population reaches the maximum number supported by environment, the carrying capacity
Carrying Capacity • Carrying Capacity: the maximum number of organisms in a population that are supported by the environment
Population Growth Graphs Reaching Limit of Resources Carrying Capacity Exponential Growth, no limiting resources
Carrying Capacity • Populations are typically limited by resources • They reach carrying capacity when there aren't enough resources to keep growing. • Birth Rate = Death Rate. • Logistic Growth!
Unlimited Growth • If there are no limiting resources, populations grow exponentially. • Birth Rate > Death Rate
Decline • If population birth rate < death rate, the population will go down!
Which of the following graphs shows a population that is free of limiting factors?
Which of the following graphs shows a population that has reached carrying capacity?
How would a scientists determine the growth rate of a population? • Birth Rate + Death Rate • Birth Rate – Death Rate • Birth Rate x Death Rate • Birth Rate / Death Rate
What statement best describes the population shown in the graph below? • Birth rate = Death rate • Birth rate < Death rate • Birth rate > Death rate • Birth rate = 0
What statement best describes the population shown in the graph below at time “t”? • Birth rate = Death rate • Birth rate < Death rate • Birth rate > Death rate • Birth rate = 0
Predator vs Prey • Predator and Prey populations can affect one another • As prey increases, predator will increase in response • As predators increase, prey will decrease • As prey decrease, predators will decrease
Bellwork: 10/18/2011 • Draw/describe the different steps/phases of the carbon cycle.
Need to take the Unit 3 Exam: • 100024330 100023993 • 100024120 100032608 • 100024354 100024047 • 100024483 100035314 • 100025297 100025116 • 100024226 100025239 • 100025269 100037530 • 100028947 • 100024571
Need to RETAKE the Unit 3 Exam: • 100036059 100024324 • 100023941 100031691 • 100024555 100023963 • 100033720 100024393 • 100024610 100033256 • 100024057 100024346 • 100023991 100024649 • 100024385 100012992 • 100023792 100034908 • 100023954 100024418 • 100025065
Human Population • Human population is currently about 6.8 billion • Human population growth has been exponential
Population Pyramid Graphs • Developing countries tend to have high growth rates, whereas developed countries tend to have stable growth. • Population age distribution • Larger at the bottom = more future growth • Equal at each age = stable growth or even decline
Population age distribution • Larger at the bottom = more future growth • Equal at each age = stable growth or even decline
Overpopulation: The Bad • The problems with overpopulation include abuse of resources: • Deforestation • Fossil Fuel Overuse • Freshwater Overuse • Pollution • Lack of adequate food • Non-native species
Deforestation • Cutting down forests leads to a loss of biodiversity: not as many different species in an area • Can affect local food webs, other species, and even medicine!