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Honors Biology
Module 7
Cellular Reproduction and DNAPart 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?
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:
1. It has genetic material (RNA or DNA)
inside a protective protein coat.
2. 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!