Classifying and Exploring Life Chapter 1 Classifying and Exploring Life

All living things, or organisms: Are made up of a cell or cells Grow and develop Reproduce Respond Maintain homeostasis Use energy

Characteristics of life: All living things: Organized by their cell(s). Unicellular organisms have only one cell

Multicellular organisms have more than one cell.

Multicellular organisms have a greater level of organization because groups of cells (tissues) function together

2. Grow and develop. 3. Reproduction. With a mate Without a mate By increasing cell size Or cell number The changes that occur during a lifetime are called development. 3. Reproduction. With a mate Without a mate

4. Respond to stimuli. Stimuli may be internal (like hunger) Or external (bright light, for example)

5. Maintain homeostasis: a stable, internal environment. 6. Use energy: for making new cells chemical reactions transporting materials

For most organisms, the energy they use originally came to Earth from the Sun.

Lesson 2 Classifying living things

Classifying living things Living things can be grouped by their characteristics. Aristotle separated organisms into 2 groups: plants and animals.

Linnaeus used 2 kingdoms to group organisms. (1700’s) Determining kingdoms Linnaeus used 2 kingdoms to group organisms. (1700’s) 5 kingdom system began in 1969: Monera, Protista, Fungi, Plantae, and Animalia.

Current system uses domains. The 3 domains are: Bacteria Archaea Determining kingdoms Current system uses domains. The 3 domains are: Bacteria Archaea Eukarya Then the organism gets classified into 1 of 6 kingdoms.

A naming system for organisms using two Latin words. Scientific Names A naming system for organisms using two Latin words. The first word is the organism’s genus example: Ursus The second word is the organism’s species example: arctos Ursus arctos is the scientific name for the brown bear.

A species is a group of organisms that have similar traits and produce fertile offspring. Similar species are grouped into 1 genus. Similar genera are grouped into 1 family. Similar families get grouped into orders. Orders get grouped into classes. Classes into phyla. Phyla into kingdoms.

Dichotomous Keys: pairs of descriptions that lead to the identification of an unknown organism. (see p. 22 in text)

Classification tools: Cladograms: branched diagram that shows the relationship among organisms, including common ancestors. (also tree or branch diagrams

Lesson 3 exploring life

Light microscopes use light and lenses to magnify the images. The Microscope Enables us to see living things that are too small for us to see on our own Light microscopes use light and lenses to magnify the images. Electron microscopes use a magnetic field to focus electrons on or through an object.

We will be using the compound light microscope in this class Magnification of the image is found by multiplying the magnification of the eyepiece with the magnification of the objective lens. Eyepiece x Objective = total magnification Ex: 10x X 40x = 400x We will be using the compound light microscope in this class

Microscope comparison light electron Can enlarge image up to 1500 X Able to view living or nonliving organisms Uses lenses to magnify the specimen Can enlarge image up to 100,000 X Able to view thinly sliced, dead organisms Uses electron beams for magnification

Images seen through these microscopes Compound light Scanning electron Blood cell Blood smear