Standard 1, Objective 2 – PowerPoint Notes
Slide 1: Carbon Cycle: Choose a starting point for Carbon.
Where is it going from there?
Take a moment to examine the slide – someone describe the process.
When is Carbon in the atmosphere a good thing?
When is Carbon in the atmosphere a bad thing?
What part of photosynthesis is Carbon? (product/generated)
What part of respiration is Carbon? (used/consumed)
Slide 3: What are the two sides of the oxygen cycle? (photosynthesis, respiration)
Can we actually “make” oxygen?
What does this slide mean by “oxygen generation”? (oxygen released to the atmosphere)
What do we call the reaction that is shown, labeled “sunlight”? (evaporation)
You’re going to want to be able to identify the four ways oxygen is consumed or used. (respiration, rust [oxidation], decomposition [breaking oxygen compounds down for re-use], combustion [rapid chemical combination of a substance with oxygen, involving the production of heat and light]).
Slides 4-8: How is nitrogen available in the atmosphere? (N2 – as a gas)
How is nitrogen available in the soil? (NH3 – ammonia, NO3 – nitric acid [nitrate], NO2 – nitrogen dioxide [nitrite])
In order to be useable by plants (producers), nitrogen needs bacteria to “fixate” the nitrogen gas by freeing their triple bonds (very strong!) so it can then be taken up and used by the plant.
Where are these bacteria? (in little nodules on the roots of plants)
The nitrogen-fixing bacteria turn the N2 into ammonia, nitric acid and nitrogen dioxide, which have weaker bonds than nitrogen gas. This makes the nitrogen useable by the plant.)
Note: Lightning is another mechanism that converts N2 to nitrates in the atmosphere, which dissolve in rain and are carried to the ground. 5-8% of total fixated nitrogen.
Slide 9: What happens when we get an abundance of condensation in the clouds? (precipitation – rain, snow, hail, sleet, fog)
What’s the difference between transpiration and evaporation? (transpiration – plants, evaporation – bodies of water)
In what part of the plant does transpiration mostly take place? (leaves)
How does the water get back into the ocean – trace the mechanism, from smallest to largest? (mountains, streams, rivers, lakes, ocean)
Slide 10: You can type these addressed in individually, or you can go to mrscbiology.com and click on the links on the Study Guide tab.
Slide 12: As we go through these limiting factors, write down the word in each paragraph provided and make just a few notes. You will be looking up limiting factor information in more detail from the book.
Limiting Factors: Things that prevent a population from growing any larger.
Environmental conditions thatlimitthe growth, abundance, or distribution of an organism or a population of organisms in an ecosystem.
[Holler out the words as they bounce in – like a game show.]
Competition – Competition for what? (space, shelter, reproduction/mating, food, water, between different species and same species)
Parasitism – Define. (one organism benefits, the other is harmed)
Space – How is space a limiting factor? (shelter from weather and predators, limit resources, allow disease to spread with larger populations, limit whether new individuals will fit [examples: barnacles on a rock], space to receive sunlight [plants]); Can you think of some other examples?
Seasonal Cycles – not density-dependent; limits certain species
Predation – density-dependent; scattered populations not as affected
Calamity – What would be an example of a calamity? (hurricane, flood, etc.)
Weather – normal and unusual weather affects certain organism populations.
Disease – Is disease density-dependent? (yes)
Food – availability and competition are both involved here.
Water – same as food
Human Activity – Give me an example of how humans can be a limiting factor in an ecosystem. (population, building homes, consuming resources, pollution, waste, overuse of water, indiscriminate hunting, etc.)
Slide 14: Which of you had the mystery vocabulary word, “evidence”? What is the definition? (what you see; facts)
How does “inference” relate to “evidence”? (hypothesis or guess, based on evidence)
Define bias, in your own words. (assumption without evidence)
Give me an example of how a scientist might be biased in their research.
As you complete the following handout, write notes in you study guide so you are sure of the concepts we are discussing.