1. Studying Life
Chapter 1.3

2. What is “Biology”
Biology is the science that seeks to understand the living world
“The study of life and how they interact”

3. Interactions
With each other
With other animals
With people

4. Characteristics of Life
What is life? What is needed to “be alive”??
How can you classify all living things?
What must they do or have the ability to do?

5. Living things share the following eight characteristics:
Living things are made up of units called cells
Living things reproduce
Living things are based on a universal genetic code
Living things grow and develop
Living things obtain and use materials and energy
Living things respond to their environment
Living things maintain a stable internal environment
Taken as a group, living things change over time

6. 1. Made up of Cells Small units that make up life
A Cell is a collection of living matter enclosed by a barrier that separates the cell from its surroundings
Can be unicellular (made up of only one cell) or multicellular (made up of many cells)

7. 2. Reproduction Must be able to produce new organisms
Can be done using:
Sexual Reproduction where two parent cells unite to form offspring or
Asexual Reproduction where the new organism has a single parent

8. 3. Based on a Genetic Code Offspring usually resemble their parents
Inherit these traits in the reproduction process
Passed on through DNA using their genetic code to produce the offspring

9. 4. Growth and Development
All living things grow during at least part of their lives
For many organisms, development includes periods of rapid and dramatic change

10. 5. Need Materials and Energy
Organisms need materials to stay alive
The combination of chemical reactions through which an organism builds up or breaks down materials as it carries out its life processes is called metabolism

11. 6. Response to the environment
Organisms detect and respond to stimuli from their environment
A Stimulus is a signal to which an organism responds
Can be external (from the environment like light or temperature) or it can be internal (from inside the organism like sugar levels in the blood)

12. 7. Maintaining Internal Balance
Things are always changing around us but we need to maintain a constant set of conditions
Homeostasis is maintaining a fairly constant set of internal conditions, such as temperature, water content, salinity, and pH
Think about sweating and shivering… think about the “Homeostasis of the Eye Lab” that we did

13. 8. As a group, we change over time
Organisms will always grow and change over time to make the best of their surroundings and conditions
Species will evolve to be better suited for their climates, food selection, and availability of other necessary resources (water, mating patterns, habitat, etc.)

14. Midway “checkpoint” questions
Lets discuss and answer the following questions:
Describe 5 characteristics of life
Compare sexual and asexual reproduction
What biological process includes chemical reactions that break down materials?
What is homeostasis?
Give two examples of homeostasis and explain how the organism maintains this “happy balance”

15. Branches of Biology
Living things come in many different shapes, sizes, and habits
Living systems also range in size from groups of molecules that make up structures inside cells to the collections of organisms that make up the biosphere.
No single biologist could study this diverse

16. What CAN we study?? Molecules Cells Organisms
Populations of a single kind of organism
Communities of different organisms in an area
The biosphere (the part of the earth that contains all ecosystems
**REALLY, we can study the smallest thing all the way up to the largest groups

17. Copy the Following Table in Your Notes
Levels of Organization
Biosphere
Ecosystem
Community
Population
Organism
Groups of Cells
Cells
Molecules
Groups of atoms; smallest unit of most chemical compounds
Increasing in Size

18. Copy the Following Table in Your Notes
Levels of Organization
Biosphere
Ecosystem
Community
Population
Organism
Groups of Cells
Cells
Smallest functional Units of life
Molecules
Groups of atoms; smallest unit of most chemical compounds
Increasing in Size

19. Copy the Following Table in Your Notes
Levels of Organization
Biosphere
Ecosystem
Community
Population
Organism
Groups of Cells
Tissues, organs, and organ systems
Cells
Smallest functional Units of life
Molecules
Groups of atoms; smallest unit of most chemical compounds
Increasing in Size

20. Copy the Following Table in Your Notes
Levels of Organization
Biosphere
Ecosystem
Community
Population
Organism
Individual living things
Groups of Cells
Tissues, organs, and organ systems
Cells
Smallest functional Units of life
Molecules
Groups of atoms; smallest unit of most chemical compounds
Increasing in Size

21. Copy the Following Table in Your Notes
Levels of Organization
Biosphere
Ecosystem
Community
Population
Group of organisms of one type that live in the same area
Organism
Individual living things
Groups of Cells
Tissues, organs, and organ systems
Cells
Smallest functional Units of life
Molecules
Groups of atoms; smallest unit of most chemical compounds
Increasing in Size

22. Copy the Following Table in Your Notes
Levels of Organization
Biosphere
Ecosystem
Community
Populations that live together in a defined area
Population
Group of organisms of one type that live in the same area
Organism
Individual living things
Groups of Cells
Tissues, organs, and organ systems
Cells
Smallest functional Units of life
Molecules
Groups of atoms; smallest unit of most chemical compounds
Increasing in Size

23. Copy the Following Table in Your Notes
Levels of Organization
Biosphere
Ecosystem
Community and its nonliving surroundings
Community
Populations that live together in a defined area
Population
Group of organisms of one type that live in the same area
Organism
Individual living things
Groups of Cells
Tissues, organs, and organ systems
Cells
Smallest functional Units of life
Molecules
Groups of atoms; smallest unit of most chemical compounds
Increasing in Size

24. Copy the Following Table in Your Notes
Levels of Organization
Biosphere
The part of earth that contains all ecosystems
Ecosystem
Community and its nonliving surroundings
Community
Populations that live together in a defined area
Population
Group of organisms of one type that live in the same area
Organism
Individual living things
Groups of Cells
Tissues, organs, and organ systems
Cells
Smallest functional Units of life
Molecules
Groups of atoms; smallest unit of most chemical compounds
Increasing in Size

26. Biology in Everyday Life
In this class, you will see that more than any other area of study, biology touches your life every day
In fact, its hard to think of anything you do that is not affected by it
Biology can help people understand that humans are capable of predicting and trying to control their future and the future of the planet

27. What do we NOW know??
1. Describe the AT LEAST 5 of the 8 characteristics of life

28. What do we NOW know??
2. What topics might biologists study at the “community” level of organization? 3. How about at the “groups of cells” level?

29. What do we NOW know??
4. What is the difference between “asexual reproduction” and “sexual reproduction”? 5. What is homeostasis? Give two examples of how homeostasis is maintained.

30. What do we NOW know??
6. What biological process includes the chemical reactions that break down materials??

31. Test Thursday!! Keep Studying!