Module 7 Cellular Reproduction and DNA- Part 2 November 19, 2015 Honors Biology Module 7 Cellular Reproduction and DNA- Part 2 November 19, 2015

Class Challenge Part 1: What are you Thankful for this year? Part 2: How many different pies can you write down in 1 minute?

Dress up in your favorite Christmas Attire. Next Class Challenge Dress up in your favorite Christmas Attire.

Quiz Identify the 5 stages of Mitosis. Draw and label each stage.

Diploid and Haploid Cells Humans have 46 chromosomes. These chromosomes come in pairs. So we have 23 chromosome pairs that total 46.

Each member of a pair are similar, but not identical.

Figure 7.8

Diploid vs. Haploid Cells http://youtu.be/zglQ2Ildw4I

Meiosis http://youtu.be/rB_8dTuh73c Figure 7.9 page 215

Viruses (Figure 7.13) A non-cellular infectious agent that has two characteristics: It has genetic material (RNA or DNA) inside a protective protein coat. It cannot reproduce on its own.

The main thing that you need to know about viruses is the way they infect their hosts. Since viruses cannot reproduce themselves, they rely on cells too do it for them. A virus will attach to a cell and then either enter the cell or inject its genetic material into the cell.

Lytic pathway (Figure 7.14) The genetic material of the virus redirects the cell’s reproductive machinery to reproduce the DNA or RNA of the virus, as well as the proteins that make up the virus. The cell’s biosynthetic machinery is then directed to assemble these pieces into new viruses. This continues until there are so many viruses that the cell ruptures, destroying the cell and releasing new viruses to infect other cells.

The time between a host receiving the virus and manifesting the symptoms of the malady caused by that virus can be several years. This is the case with HIV, the virus that causes AIDS (acquired immune deficiency syndrome).

Viruses Some examples of the many diseases and afflictions: Warts, chicken pox, the common cold, influenza, some forms of cancer, mumps, measles, AIDS, Cold sores. Can you think of other examples? Plants can be killed by viral infections as well.

Virus http://youtu.be/L8oHs7G_syI

Infection Fighting Agents In most organisms, there are infection-fighting agents that can destroy viruses and other pathogens. Phagocytic cells: engulf a chemical or another cell to destroy it. Some white blood cells are phogocytic cells.

White Blood Cells Circulate in the bloodstream and when infection strikes, they can leave the bloodstream and go to the point of infection in order to engulf the pathogen. The lymph nodes contain phagocytic cells. Special vessels called lymph vessels carry fluids through the lymph nodes, and pathogens that are in that fluid get engulfed by the phagocytic cells that are there.

Antibodies Are specialized proteins that aid in destroying infectious agents. When your body is infected by a pathogen, specialized cells work to produce antibodies that will help to destroy that pathogen. Once the cells are successful at producing such an antibody, other cells are produced that actually remember how to produce the antibody.

Fighting Infection If you happen to get infected by the same pathogen again (or one very similar to it), those cells will immediately help to produce the antibody that they know is successful against that pathogen. This increases the speed at which your body can fight off the pathogen and will make it less likely that you will get sick from that infection.

Vaccines This is the principal behind vaccines, the most common way that medical science can fight viruses. A vaccine is a weakened or inactive version of a pathogen that stimulates the body’s production of antibodies which can aid in destroying the pathogen.

The Effectiveness of Vaccines Figure 7.15 (p. 221) Look at the incident rates for Polio and Measles cases.

Flu Attack! How A Virus Invades Your Body http://youtu.be/Rpj0emEGShQ

Curiosity - World's Dirtiest Man How Dirty is Your Bathroom? http://youtu.be/cqNus5AIHR4 A Dog's Mouth http://youtu.be/FGI750uwius Cough Grosser Than Sneeze? http://youtu.be/dy1D3d1FBcw

Homework Finish reading Module 7 Complete the OYO definitions and questions Complete the Study Guide Take Module 7 Test Begin reading Module 8 (pages 226-247) Class Quiz: Meiosis 1 and Meiosis 2 Class Challenge: Christmas Attire Happy Thanksgiving!