1. BIOLOGY
THE SCOPE OF LIFE

2. TWO WAYS TO STUDY BIOLOGY
Discovery approach: observe and describe objects at many levels
- ie. Dissection, Human genome project, description of DNA
Hypothesis based approach:
- propose a hypothesis, make deduction, test prediction
TWO WAYS TO STUDY BIOLOGY

3. The Scientific Method

4. Steps to solving a problem using the scientific method.
State the problem
Form a hypothesis
Test hypothesis
Steps to solving a problem using the scientific method.

5. Testing the hypothesis
Control Group – no change
Experimental Group – changes
Testing the hypothesis

6. Testing : (cont.) Involves variables – something that changes
Two types of variables
- Independent – the one that you change
- Dependent – the one that changes because of the independent variable
Testing : (cont.)

7. Record & analyze data
Form a conclusion
Replicate
Steps cont’d

8. CONTROLLED EXPERIMENTS

9. Sample experiment Problem
- Does the temperature of air cause leaves of maple trees to change color?
Hypothesis
- Colder temperatures cause change in color of maple trees.
Sample experiment

10. Testing the hypothesis
Independent variable – temperature
Dependent variable – change in color
Testing the hypothesis

11. Control group
- a group of maple trees that are kept at room temperature (22° C)
Experimental group
- a group of maple trees that are kept at colder temperatures (14° C)
CONT.

12. Collection of Data (Qualitative & Quantitative)
Count number of green leaves each day
Run experiment for a given number of days
- You need at least days of data for plants
Record data on a chart
Plot data on graph
Collection of Data (Qualitative & Quantitative)

13. Cold temperatures do not cause maple leaves to change color
Form a Conclusion

14. The Properties of Life

15. 1. Made of Cells Unicellular – single celled
Multicellular – many cells
Prokaryotic- simpler, smaller, does not have a nucleus or most organelles.
Eukaryotic –most forms of life, contains a definite membrane- bound nucleus and other organelles
1. Made of Cells

16. 2. REPRODUCE Sexual -- 2 cells required
Asexual -- single organism reproduces
2. REPRODUCE

17. 3. GROW AND DEVELOP

18. 4. OBTAIN & USE ENERGY Anabolism
- putting substances together thus storing energy
- photosynthesis
- protein synthesis
Catabolism
- breaking down substances thus releasing energy
- digestion
Metabolism
- sum total of all chemical reactions in organism
4. OBTAIN & USE ENERGY

19. 5. RESPOND TO ENVIRONMENT
Stimuli
- anything that causes a response
Responses
- improve chances for survival
- maintain homeostasis which is the balance within the organism
5. RESPOND TO ENVIRONMENT

20. Scientists continue to try to classify all life
Scientists continue to try to classify all life. There are many different classification schemes.
Most agree on 3 groups called domains.
DIVERSITY OF LIFE

21. 3 Domains:
- Bacteria
- Archae
-Eukarya
DIVERSITY OF LIFE

22. DIVERSITY OF LIFE Kingdoms – change is still in the works - Plants
- Animals
- Fungi
- Many kingdoms of Protists
DIVERSITY OF LIFE

23. BRANCHES AND LEVELS OF BIOLOGY

24. BRANCHES Zoology - animals Botany - plants Microbiology
- microscopic organisms
Ecology
- how organisms interact with environment
BRANCHES

25. Molecular
Organelle
Cellular
Tissue
Organ
Organ systems
LEVELS

26. Organism
Population
Community
Ecosystem
Biosphere
Levels

27. Evolution: Biology’s Unifying Theme
Evolution- genetic change in a population over time
Charles Darwin- Father of Evolution
-Descent with modification
-Natural Selection
(Reproductive Success)
Evolution: Biology’s Unifying Theme

28. The Evolutionary Tree of Mammals
This chart illustrates how the various mammal groups are related to one another. Groups that share more recent common ancestors are located on branches that are closer to each other.
The Evolutionary Tree of Mammals

29. ECOLOGY
Interactions of organisms w/each other & their physical environment

30. Population - Individuals of same species living in a given area
Population - Individuals of same species living in a given area. A species must breed with each other.
Community – All the populations in a given area.
Limiting factor – factors that restrict population growth
- water, oxygen, light
Terms

31. Terms Ecosystem – a community and its physical factors (abiotic)
Biosphere - Part of earth where life exists – sum of all ecosystems
Terms

32. Producer – makes organic food CO2, H2O, and other inorganic material(Primary,Secondary,tertiary)
Consumer – gets food by eating plants or organisms that ate plant
Decomposer – gets energy from organic waste or dead organisms
- (aka detritivore)
Foodchains:
Grass →antelope→human→lion
Food web: all the food chains in an ecosystem
Terms

33. Question How is a community different from an ecosystem?
- Community refers to only the living org. while ecosystem refers to both abiotic and biotic factors.
Question

34. Ecological Succession
Change in ecosystem over time.
Examples:
- worms change soil
- trees grow tall and shade forest
- both of these affect other life forms
Ecological Succession

35. Ecological Succession
Ecological succession leads to “climax community” which is fairly stable
Is it ever reached? Why or Why not?
Example
- beech-maple forest
- bog
Ecological Succession

36. Pop. Density Predators and Prey-survival relationship which
gives an ecosystem diversity of niches.(role of organism)
Predator-an organism that actively hunts other organisms. The organism that is being hunted is the prey.
The abiotic and biotic factors that define a Niche, also limit a specie’s growth, by limiting population size.
Ex: more food in summer/winter.
Any population has the potential to increase exponentially, that is where the growth in each generation is a multiple of the previous generation, IF it has a perfect environment. The Growth curve would look like a “J.”
Pop. Density

37. The number of individuals that can be supported by an ecosystem is called the
CARRYING CAPACITY for that specie
Carrying capacity of a specie in a particular ecosystem is usually represented by an S- shaped graph or “logistic growth curve”
Growth Curves

38. Limiting factors Density Dependent limiting factors-
Limiting factors that are dependent on population size. Ex: food supply, predation, disease, competition.
Density-independent limiting factors-limiting factors that affects the same percentage of a population regardless of its size. EX: natural disasters (hurricanes, fires) limit growth by destroying habitat
Limiting factors

39. Humans effects on ecosystems
Pollution
Global Warming – pg
Deforestation
Humans effects on ecosystems

42.  biodiversity  the variety of life on Earth, along with the habitats they depend upon
-biodiversity hot spots-small areas with lg. # of endangered and threatened species
Main goal of conservation biology- counter the loss of biodiversity
Sustainable development-"Development that meets the needs of the present without compromising the ability of future generations to meet their own needs."
Terms

43. The Human Population Studies of the Human ecological footprints show:
Already overshot the planet’s capacity to sustain us
US consumes a disproportionate amount of food and fuel
Number one country contributing to fossil fuel depletion and greenhouse gases
Our growth curve has been an exponential one for a long period of time.
The Human Population