Maple trees + ants + grasses + birds + pond + water + rocks Warm Up: Put these Levels of Organization in the correct order from Atom to Biosphere Maple trees + ants + grasses + birds + pond + water + rocks Carbon Tree Roots Maple Tree Grove Maple Tree Glucose Ground Tissue Temperate Forrest Maple trees + ants + grass + birds Earth Palisade cell Vascular System Chloroplast

Immune System Response to Antigens and Pathogens How your body reacts to a foreign invader.

Important Terms Immune System - a network of cells, tissues, and organs that work together to protect the body. The cells involved are white blood cells, or leukocytes, which come in two basic types that combine to seek out and destroy disease-causing organisms or substances. Antigen - a toxin or other foreign substance that induces an immune response in the body, especially the production of antibodies.

Important Terms Pathogen - a bacterium, virus, or other microorganism that can cause disease. Antibody - a blood protein produced in response to and counteracting a specific antigen. Antibodies combine chemically with substances that the body recognizes as alien, such as bacteria, viruses, and foreign substances in the blood. WBC – White Blood Cells

1st Line of Defense Examples of the 1st Line of Defense include: Skin The first line of defense against an antigen occurs outside of the body with the skin and mucus membranes which work together to repel foreign substances and organisms. Examples of the 1st Line of Defense include: Skin Mucus Sweat Tears Examples of the 1st Line of Defense include: Inflammatory Response such as a Rash, Swelling, Sneezing

2nd Line of Defense The second line of defense occurs when a foreign object or substance enters the body. Inside the body, a series of events occur between different types of cells to attack and dispose of the foreign invader. To illustrate this, we will use an analogy called the “Pac-Man Response”.

T-Cell (The General) – Receives the information that an antigen has entered the body and sends orders to the B-Cells to create an antibody army to find and fight the antigen. Skin and Mucus Membranes Antigen – Bad Guy; Virus, Bacteria or other pathogen Antibody Army Tells T-Cell B-Cell – receives orders from the General and creates an army of antibodies made to fit onto the antigen to eliminate it. Macrophage – WBC; the Good Guy; eats the antigen and reports what the antigen looks like to the T-Cells.

Antibodies locking onto antigens to remove them from the body. Diarrhea Diarrhea Diarrhea

What happens when a virus like HIV attacks the T-Cells? New Antigen Enters X ??? No orders come from T-Cell to tell B-Cell to create the antibody army. Tells T-Cell about antigen The HIV virus destroys T-Cells in the body. That means the T-Cells can no longer communicate with the B-Cells B-Cell can’t make antibodies to fight new antigens.

Importance of Vaccines A vaccine is a deactivated or mild form of a virus. The purpose of the vaccine is to trigger the body’s immune system response to the virus in order to create the army of antibodies to fight the virus. This prepares the body to fight the stronger form of the virus when it enters the body. A virus can never be eliminated or killed; only contained and deactivated. It still lives in your body, dormant.

Viruses have a protein coat and genetic material Viruses have a protein coat and genetic material. This allows them to enter a cell undetected, IF they have the KEY!

How come humans can’t get the Tobacco Mosaic Virus? Viruses can only infect the host that they are intended for. The proteins on the surface of the virus fit the proteins on the surface of a host cell like this key fits this lock.

LYTIC CYCLE DRAW and LABEL

Active Viruses Enter cell. Take over cell functions. Produce more viruses. Cell bursts releasing lots of new viruses. Those viruses infect more cells. The LYTIC CYCLE is SHORT! You can get the virus today, and be infected by tomorrow!

LYSOGENIC CYCLE DO NOT DRAW!

Hidden Viruses Enter cell and the Virus’ genetic material becomes part of the cell’s genetic material. (It Hides!) The Virus is dormant for a long time. Then, SUDDENLY, the dormant virus becomes active! Takes over cell functions. Produces more viruses. Cell bursts releasing lots of new viruses. Those viruses infect more cells. The LYSOGENIC CYCLE is LONG! You can get the virus today, but not get sick for months or years or DECADES!

between an active and hidden What is the difference between an active and hidden virus? The genetic material of a hidden virus can “hide” inside of the cell. It is undetected or hidden so the cell can not attack the virus! You can NEVER get rid of a hidden virus…EVER.