1. Life in the earth system
Unit1: Intro to biology

2. Big questions How are the Earth Systems organized?
How do the systems interact to maintain organization?
How do we classify something as biotic or abiotic? (living or non-living)

3. Studying Science Scientific Method- PHEOC
Problem, Hypothesis, Experiment, Observation, Conclusion
A scientific theory is NOT a wild guess. It must be consistent with known experimental results and it must have predictive power. As new knowledge is gained, theories are refined to better explain the data.
A law is a mathematical relationship that is consistently found to be true.
Can YOU think of an example of a theory and a law in science?

5. Studying science
Hypothesis- Proposed scientific explanation (answer) for the problem the scientist is attempting to figure out.
Independent Variable- The factor that is changed by the scientists in order to prove -or- disprove the hypothesis. CHANGE ONE AT A TIME
Dependent Variable- The factor that is measured or observed as the independent variable is changed.
Control- A factor kept the same in order to pinpoint where and why the change is taking place.

6. Studying science Qualitative Data- Observations in words. Description
Quantitative Data- Numbers used to make data tables or comparisons

7. Let’s do some science!
Capsule Lab

8. Title
Dependent Variable
Units and Scale
Independent Variable

9. Being Alive Look at problems in many ways Ex/ disease
Look at DNA
Cell Structure
Influence of Diet
Basic Organization:
Cell
Tissue
Organ
Organ System
Organism
Biotic- Living
Abiotic- Non-living
Dead- Once Alive

10. How do we tell?

11. Rule #1: Living things are made of cells
Cells are the units of structure in living organisms
Also units of function in living organisms
Cell = smallest unit capable of all life functions

12. Rule #2: Living things reproduce
They can make more of themselves
Two kinds of “Getting’ Jiggy With It”
sexual reproduction = two cells from different parents unite
-ex. Your mommy and daddy (ewww!), dogs, cats, worms,
asexual reproduction = new organism has a single parent
-ex. Some plants, bacteria, starfish (!!!)

13. Rule #3: Living things are based on genetic code
Have DNA
Can pass on traits

14. Rule #4: Living things grow and develop
Even single celled organisms grow into mature cells
Organism= what scientists call living things

15. Rule #5: Living things have a metabolism
Metabolism = combination of chemical reactions through which an organism builds up / breaks down materials as it carries out its life processes
Energy is used to perform chemical reactions
Materials (nutrients) are the raw materials for building biological structures

16. Rule #6: Living things respond to their environment
Stimuli = A physical or chemical change in the environment that leads to a response
Respond = to act or do something in reaction to something else
Can be INTERNAL STIMULUS or EXTERNAL STIMULUS
Thirst, pain, hunger, cold, hot………

17. Rule #7: Living things maintain homeostasis
Homeostasis= maintaining stable internal conditions
Homeo = similar/alike
Stasis = state of no change

18. Rule #8: Living things, as a group, change over time
Great diversity of life on Earth
Adapt to the environment (changing environment)
Adaptations can be structural, physiological, behavioral
Populations show variations in their genetic code
Evolution = ability of group of organisms to change over time

19. Let’s Focus on Homeostasis
LAB TIME!

20. Life in the earth system
System- set of interacting components that work together
Inputs and outputs- outputs (what we see/ feel) are generated when inputs (message to brain and hormones) are analyzed in some way
Feedback- information from one step of a cycle that acts to change a behavior of a previous step
Feedback Loop- feedback output that in turn becomes an input

21. Negative Feedback Loop
Imbalance message received and inputs signal opposite to output.
Ex/ I am hot (output) therefore I will sweat (input)
Thermoregulation (if body temperature changes, mechanisms are induced to restore normal levels)
Blood sugar regulation (insulin lowers blood glucose when levels are high ; glucagon raises blood glucose when levels are low)

23. Positive Feedback Loop
Reinforcing mechanism that adjusts output in the same direction as the input
Very rare
Examples of processes that utilize positive feedback loops include:
Childbirth – stretching of uterine walls cause contractions that further stretch the walls (this continues until birthing occurs)
Lactation – the child feeding stimulates milk production which causes further feeding (continues until baby stops feeding)
Blood clotting – platelets release clotting factors which cause more platelets to aggregate at the site of injury