Today’s Big Question: What is Life? Bell ringer: What is the difference between a theory and a law?

What is Life? Today we are going to be talking about what is life You will each need a sheet of paper for this activity

This is how your paper should look Item Alive or No? Why

What do living things have in common? Characteristics of Living Things Characteristics of Non-living Things What do living things have in common?

Is Fire Alive What properties does fire have that make it seem living? What properties make it seem non-living?

6 Characteristics of Living Things Are organized into cells Use energy Grow and Develop Respond to their Environment Reproduce Maintains Homeostasis

What is alive? ALIVE NOT ALIVE

Exit Ticket On your way out, please answer the following question: Is fire alive? Why or why not?

Characteristics of Living Things Bell ringer: what are the 6 things that all living things do? Also, take out your homework- I will check it

6 Characteristics of Living Things Are organized into cells Grow and Develop Reproduce Respond to their Environment Use energy Maintains Homeostasis

1. Organized into Cells Anything living is called an organism A cell is every organism’s smallest unit of life. Unicellular organisms are organisms made of only one cell. Living things that are made of two or more cells are called multicellular organisms.

2. Grow and Develop Changes that occur in an organism during its lifetime are called development.

3. Reproduce Reproduction is the process by which one organism makes one or more new organisms. Some organisms can reproduce by dividing and becoming two new organisms. Some organisms must have a mate to reproduce, but others can reproduce without a mate.

4. Respond to their Environment All living things respond to changes in the environment called stimuli. Internal stimuli are changes within an organism. External stimuli are changes in an organism’s environment.

5. Homeostasis An organism’s ability to maintain steady internal conditions when outside conditions change is called homeostasis. http://www.brainpop.com/health/bodysystems/homeostasis/

6. Use Energy Cells continuously use energy to transport substances, make new cells, and perform chemical reactions. For most organisms, energy for life comes from the Sun. The Sun’s energy can be passed from one organism to another.

Review What is the term to describe a living thing?

Review What does “homeostasis” mean?

Review What is the smallest unit of life?

Review Where does most of the energy organisms use ultimately come from?

Review What is a “unicellular organism”? Are humans unicellular?

Workbook page 61 Answer questions 1,2 and 3

How Do We Classify Life? Bell ringer: What is homeostasis?

How is Life Classified? Take a look at my really disorganized desk. How could you go about sorting things out?

How is Life Classified? There have been many different ideas about how to organize, or classify, living things. Carolus Linnaeus classified organisms into two main groups, called kingdoms, based on similar structures.

How is Life Classified? The current classification method for organisms is called systematics. Systematics uses all known evidence to classify organisms, including what it looks like, how it behaves, common ancestors and DNA.

How is Life Classified? We put things in categories called “taxa” Organisms are now classified into one of three domains and then into one of six kingdoms. After that there is phylum, then class, order, family, genus and finally species

Species Species refers to organisms that can have viable (living) offspring So all dogs (German shepherds to Chihuahuas) are all members of the same species!

http://www.brainpop.com/science/diversityoflife/classification/

How is Life Classified? Linnaeus developed something called “binomial nomenclature” Binomial nomenclature is a system for naming organisms with two-word scientific name: A species is a group of organisms that have similar traits and are able to produce fertile offspring. A genus is a group of similar species.

Binomial Nomenclature In this system, animals are given Latin names The first name is the genus and the second name is the species The genus is capitalized, but the species name is not. They are italicized when typed out. For example, humans are Homo sapiens Sometimes the genus is abbreviated.

Some Scientific Names Can you guess what these are? Canis lupus familiaris Felis catus Trichechus manatus Loxodonta africana Malus domestica Trichophyton rubrum

How do Scientists Study Life?

Microscopes Much of life is too small to be seen by the eye Microscopes allow humans to view details of living things that could not be seen with the unaided eye. Microscopes were invented by Anton van Leeuwenhoek in the late 1600’s.

Types of Microscopes A compound microscope is a light microscope that uses more than one lens to enlarge images up to 1,500 times their original size. In this class we use compound microscopes

Types of Microscopes An electron microscope can magnify an image up to 100,000 times or more. There are 2 kinds: Transmission Electron Microscopes- view small sliced sections Scanning Electron Microscopes- view the outside of an object, make 3D images

Types of microscopes Since electron microscopes only work in a vacuum (a place with nothing- not even air), the specimen must be dead Compound microscopes can be used to view living things

Who Needs Microscopes? Doctors, including surgeons Veterinarians Microbiologists Forensic scientists Paleontologists Environmental scientists Material scientists