Chapter 8Chapter 8Chapter 8Chapter 8

Life’s Structures and Life’s Structures and ClassificationClassification

I. Living Things-organism – any living thing

A. Characteristics of Living Things1. Living things are organized

a) cell – smallest unit of an organism that carries on functions of life

2. Living things grow and develop3. Living things respond to a stimulus

a) stimulus – anything that causes some change in an organism

4. Living things maintain homeostasisa) homeostasis – the regulation of an organism’s internal, life-maintaining condition despite changes in its environment

5. Living things use energy6. Living things reproduce

B. Needs of Living Things

1. A place to live2. Water3. Food

II. How are Living Things Classified?-Classification – putting objects

into groups based upon common characteristics

A. Modern Classification-Aristotle classified living things into

3 groups – air, land, and water

-Carolus Linnaeus came up with the modern system of classification

1. Modern Classification System

Kingdom

Phylum

Class

Order

Family

Genus

Species

Organisms are more similar than the group above it.

More members in it than the group below it.

2. Modern Scientific Naming System

a) Binomial Nomenclature – two word naming system-Uses Latin.-First word is the Genus and is capitalized.-Second word is the species and is lowercase.-Both words are underlined or italicized.

Link to Scientific Names Worksheet

3. Tools for Identifying Organismsa) Field Guide – book with

descriptions and illustrationsb) Dichotomous Key – a detailed

list of identifying characteristics that includes scientific names

Link to Dichotomous Key for Quozes Identification

Link to Quozes Pictures

Link to Quozes Answer Sheet

Link to Norns worksheet

III. Cell Structure

A. Cell Theory (developed by Hooke, Schleiden, Schwann, and Virchow)

1. All organisms are made up of one or more cells.

2. The cell is the basic unit of organization in organisms.

3. All cells come from cells.Link to Microscope Parts and Functions

B. Cellular Organization-Prokaryotic – cells without membrane

bound structures (bacteria)-Eukaryotic – cells with membrane

bound structures (animals and plants)-Organelles – structures in cytoplasm

of eukaryotic cells

Link to cells under microscope lab worksheet

Link to cellsalive.com worksheetwww.cellsalive.com

Plant and Animal Cell Diagram

1. Animal Cellsa) Nucleus – largest organelle; It controls all activities of the cellb) Cell Membrane – a protective layer that covers the cellc) Cytoplasm – a gelatin-like substance inside the cell

d) Ribosomes – structures that make proteins

e) Mitochondria – where energy is produced from food

f) Endoplasmic Reticulum (E.R.) – folded membrane in which materials can be processed and moved inside the cell

g) Golgi Bodies – sort and package proteins

h) Lysosomes – break down food molecules, cell wastes, and worn out cell parts

i) Vacuoles – store water, food, and waste products

Link to cell city intro Link to cell city descriptions

Sample Cell City Link to Cell City Instructions

Link to Cell City Sketch Link to Cell City Rubric

2. Plant Cells-Plant cells have the same

organelles as animal cells but also have the following:a) Cell Walls – tough, rigid outer coverings that protect the cell and give them shapeb) Chloroplasts – green organelles where food is made

C. Many-Celled Organisms

1. Cells→Tissue→Organs→Organ Systems

2. Tissue – a group of similar cells that work together to do one job

3. Organs – structures made up of 2 or more types of tissue that work together

4. Organ System – a group of organs working together to perform certain functions

IV. VirusesA. What are Viruses?

-virus – strand of hereditary material surrounded by a protein coating

-host cell – a living cell that helps the viruses to make copies of themselves

1. Active Viruses – the viruses cause the host cells to make new viruses which destroys the host cells.

2. Latent Viruses – viruses do not immediately make new viruses or destroy the cells.

B. Treating and Preventing Viral Diseases1. Natural Immunity

a) Interferons protect noninfected cells.

2. Vaccines

C. Research with Viruses1. Gene Therapy2. HIV/AIDS research