Presentation on theme: "Populations. DAY 1 - Ecology and Populations Bell- What is Ecology What is a Population? AGENDA Ecology Intro Bacteria growth Corn Growth HW - Embed a."— Presentation transcript:
Population growth Graph a Bacteria population Bacteria divide every 20 minutes Create a line graph that shows the Population Growth of bacteria over a 3 hour and 20 minute period. Assume that the population starts with 1 bacteria and there are unlimited resources.
Corn Graph Create another graph: population of corn How many seeds does each generation produce? Create Graph of showing 10 years (generations). Assume that only 30 kernels become plants each year.
Bacteria and Corn DO the graphs have similar shape What does it look like? Letter? Exhibit Exponential Growth J- Curve Population will grow exponentially with unlimited resources
OH DEER Deer simulation - OUTSIDE 10 Years (rounds) Deer vs. Shelter, Food, Water Create a graph showing the deer population
OH Deer Demonstrates Logistic Growth (S-Curve) Population Grows to Carrying Capacity Carrying Capacity is determined by Limiting Factors
Logistic Growth Limiting Factors - Lower population size Competition Predation Disease (including Parasitism) Natural disasters (ex. Drought) Human Disturbance
Human Population 1492 - 2/ minute 1940 - 40 1950 - 88 1970 - 138 1995- 176 2000- 168
Human Population What Type of Growth are we experiencing? Can it continue?
Day 3 - Populations Watch Video - decide on relationship AGENDA Limiting Factors Energy Flow Natural Selection Lab
Limiting Factors Which are Density Dependent? Competition, Predation, Disease Which are Density Independent?
Energy Flow ✦ Energy from the sun enters an ecosystem through photosynthesis ✦ plants use light energy to make sugars (carbohydrates) ✦ energy is used to carry out daily activities
Bell Ringer ✦ If a stream is too warm to support Trout, is that a biotic or abiotic factor?
Answer: ✦ Abiotic Abiotic Factors-Non living factors rock, sun, air, water, temperature
Producer vs. Consumer ✦ Autotroph= Producer: ✦ an organism that makes its own food; ✦ receives direct energy from the sun
Producer vs. Consumer ✦ Consumer: an organism that gets its energy by eating other organisms; ✦ receives energy indirectly from the sun
Types of Consumers ✦H✦Herbivores - plant eaters - Primary consumer ✦C✦Carnivores - flesh eaters - Secondary consumers, Tertiary consumers, etc. ✦O✦Omnivores - eaters of all ✦D✦Detritivores (decomposers) - break down dead organisms to return nutrients to the soil, water and air
Food Chain ✦ the sequence in which energy is transferred from one organism to next as each organism eats another organism
Food Web ✦ energy flow in an ecosystem is more complex than that of a simple food chain ✦ Why? ✦ most organisms eat more than one type of food ✦ food webs show all feeding relationships possible in an ecosystem ✦ multiple food chains What happens if the grass is removed?
Trophic Levels ✦ each step through which energy is transferred in a food chain is a trophic level ✦ Producer - Primary consumer - secondary consumer - tertiary consumer ✦ when energy is transferred, some is lost as: ✦ heat, etc. - means less energy is available to organisms at the next level ✦ 90% of the energy is used ✦ 10% is stored and passed on to next level
Ecological Pyramids ✦ diagrams that show the relative amounts of energy or matter within each trophic level of a food chain/web ✦ 3 Types ✦ Energy Pyramids ✦ Biomass Pyramids ✦ Pyramid of Numbers
Energy Pyramids ✦ Reminder: ✦ each layer represents one trophic level ✦ producers form the base (contain most energy) ✦ high level consumers make up top layer (less energy is available)
Energy Pyramid Problem ✦ Use the following information about this food chain to create an energy pyramid. ✦ Grass --> Grasshopper --> Frog --> Heron ✦ Assume that there are 175,000 calories available in all the grass plants in this food chain. ✦ Label each trophic level. Show the # of calories available at each level.
Biomass Pyramid ✦ biomass = the total amount of living tissue within a trophic level ✦ where is the biomass the greatest? ✦ base of the pyramid
Pyramid of Numbers ✦ shows the relative number of individual organisms at each trophic level
DAY 4 - Populations BELL: What happened to the Greenus Beanus and the Varietus Beanus populations? Which had the higher growth rate? Which had the higher reproductive Rate (percent left for reproduction)? Why did the Varietus Beanus population still grow? Did one phenotype reproduce more than any others? AGENDA Population Changes - Hardy-Weinberg A mutation Story *Turn in your Natural Selection Graphs and Answered questions