1. Life’s Structure and Classification

2. Living Things

3. What are living things like?
Any living thing is called an organism
Organisms can be different sizes- from microscopic things like bacteria, to large things like giant oak trees.
They may behave differently, and have different needs, but there are traits (characteristics) they have in common that distinguish them from non-living things.
What are living things like?

4. Living Things are Organized
The cell is the smallest unit of structure and function of living things.
They take in materials from their environment and use them to help the organism function.
Some organisms are made of as few as one cell, while others are made of complex groups of cells
Each cell has a structure specific to it’s job, and has within it directions for how to do the job it’s supposed to do.
Living Things are Organized

5. Living Things Grow and Develop
Growth in a single celled organism is due to the increase in size of the one cell.
There is a limit to how large any cell can grow.
Growth in a multi-cellular organism is due to an increase in the number of cells.
Organisms change as they grow. This is called development.
How long an organism is expected to live is called the life span.
Living Things Grow and Develop

6. Living organisms interact with their environment in order to survive.
A stimulus is anything that causes an organism to react.
The reaction is known as the response.
Living Things Respond

7. Living Things Maintain Homeostasis
Organisms also respond to stimuli from within them.
Example: If you are running on a hot day, your body temperature increases. Your body reacts by making you sweat.
This inner ability of any organism to balance the outside conditions by changing a condition within them is called homeostasis.
How different organisms do this varies.
Living Things Maintain Homeostasis

8. Living Things Use Energy
Carrying on life activities requires energy.
Most organisms get their energy either directly or indirectly from the Sun.
Some use the Sun’s light directly to make their own food that they use for energy.
Others don’t have that ability, so they take in those that do, and use their energy.
Some organisms need oxygen in order to release the energy from their food, while others don’t.
Living Things Use Energy

9. Living Things Reproduce
Living things must replace themselves with others that will continue to live after they die. The method by which this happens is called reproduction.
Not all members of a given type of organism must reproduce, but if NONE of them reproduce, then the organisms will disappear (become extinct).
Living Things Reproduce

10. What do living things need?
All organisms need a place to live that is suited to their specific survival needs.
All organisms need to take in water from their environment.
All organisms need to have sources from which to take in food or make food, that meets the proper amounts and varieties of elements and compounds needed for them to continue to perform the complex chemical activities of life.
What do living things need?

11. Review Living things are also known as what?
Living things are also known as organisms.
What traits do all living things share?
All living things are organized, grow and develop, respond to their environment, maintain homeostasis, use energy, and reproduce.
What do all living things need?
All living things need a place to live, water, and a source of food in order to survive.
Review

12. How are living things classified?

13. Classification Grouping organisms together is known as classification.
Many different systems were used throughout history until Carolus Linnaeus (Sweden) developed a system in the late 18th century, that is still used today, called Binomial Nomenclature.
Classification

14. Binomial Nomenclature
Binomial Nomenclature literally means a two-word naming system. (binomial = two names nomenclature = naming system)
Latin is the language used for the system.
The first word of a scientific name identifies the organism’s genus – (a group of similar species).
The second word can describe a trait of the organism, identify a place (usually where it was discovered), or honor an individual (usually the person who discovered it).
Binomial Nomenclature

15. Uses of Scientific Names
Why are Scientific names used? 4 Reasons.
They help distinguish between organisms that have similar names.
Since organisms with similar evolutionary histories are grouped together, you know which organisms are related.
They give descriptive information about a group of organisms.
They allow for information to be organized easily and efficiently.
Uses of Scientific Names

16. Modern Classification
Modern scientists use similarities in structure, fossils, hereditary information, and early stages of development to help them determine an organism’s phylogeny, (the evolutionary history of the organism).
Modern Classification

17. Modern Classification
Domains- Some Scientists believe this should be the largest group, and that all organisms should be divided into three groups. The organisms in a domain have the fewest number of traits in common.
As you move through the groups, the organisms in that group have more and more in common, and the groups become smaller. Think of it as an upside-down pyramid.
Kingdom
Phylum
Class
Order
Family
Genus
Species
Modern Classification

18. Modern Classification Continued…

19. Tools for Identifying Organisms
Field Guides and Dichotomous Keys are used to identify organisms.
Field guides usually contain pictures and descriptions of organisms, as well as information about where they live.
Dichotomous Keys are detailed lists of traits, where you choose between two possibilities, which lead to a conclusion about which organism you’re identifying.
Tools for Identifying Organisms

20. Dichotomous Key Example

21. **What sorts of questions would show that you really understand the most important concepts in this section?
On looseleaf paper, write 3 questions, and the answers that go with them, (in complete sentences) from the section of these notes titled “How are Living Things Classified?”
Be sure to show which is the question, and which is the answer.
Turn them in when finished.
Review

22. Classification Lab Conclusion
On Loose-leaf paper, using the same process that you just used to identify the Kingdom, Phyla and Classes of the shapes in Kingdom1, find and name the Kingdom, Phyla and Classes for the shapes in Kingdom 2.
Label the Class shapes with the letters C and D.
Classification Lab Conclusion