1. The Unifying Themes of Biology

2. Intro Life has many levels of organization, and great diversity
There are several themes that help to unify the different aspects of biology

3. Target #19- I can describe how the living world is a hierarchical system
System: A combination of parts that make up a more complex whole
Exists on all scales
Microscopic to biosphere
Scientists can work within one system
Ex: studying predator-prey relationships in ecology
Scientists can also study “across systems”
Ex: study how chemicals in the brain affect social interactions

4. Systems also apply to classification/organizati on of organisms
Identification- taxonomy
Evolutionary relationships- phylogeny
Ecological organization
Illustrates close relationships between organisms
Shows shared characteristics

5. Target #20- I can describe the cellular basis of life
Cells
The basic unit of structure and function in all organisms
Two main types
Prokaryote
Bacteria
Archaea
Eukaryote
Protists
Plants
Fungi
Animals
In multicellular organisms, cells are organized
Cell specific types
Tissues made of many cells
Organ made of tissues
Organ system made of several organs with similar functions
Multicellular organization is a part of the hierarchical system found in biology

6. Target #21- I can state why genetic information must be heritable
Heritable Information
The continuity of life depends on the inheritance of biological information in the form of DNA
Encoded in a nucleotide sequence of the DNA
Must be able to be passed down from parent to offspring
Target #21- I can state why genetic information must be heritable

7. Target #22- I can give an example of how structure is related to function
Structure & Function are related
What something does in an organism is directly related to its shape or form
Related at many different levels micro & macro
Ex: different types of proteins that play separate roles in cellular function
Ex: different types of cells have very different functions and structures
Nerve cell vs. skin cell

8. Target #23- I can explain the role of negative feed back loops
Regulation
Feedback mechanisms regulate biological systems
Helps to maintain homeostasis
regulated through negative feedback loops
a change in a system causes a response that tends to return that system to its original state.

10. Evolution
The core, and most significant, unifying theme
Explains both the unity and diversity of life
Evolution is the change in the genetic make-up of a sub-group, or population, of a species
Occurs through the process of natural selection of adaptations, or traits, found in different organisms
Those that are more successful than their peers at reproducing will be able to pass down their genetic information more frequently than their peers.
Target #24- I can state how evolution explains both the diversity & unity of life

11. As you study biology, you will see time after time that organisms are related to one another
Ex: Organisms have similar cell structures and chemical processes
Shared characteristics result from a common evolutionary descent
Ex: humans and bacteria