05.04.2020 - Science notes -

05.04.2020 – Monday – Science –

Remember to copy the notes in your notebook and define CAPITALIZED terms.

I.  Current Events:  Link to CNN - https://www.cnn.com/cnn10

            A.  Two notes on Invasive “Murder Hornets.” …

            B.  Like honeybees haven’t had it hard enough lately. We’ve studied how pesticides, and other stresses, have caused a decline in bee populations. Honeybees are important for the POLLINATION of crops all over the world.

                        1.  One of the biggest reasons for species extinction is INVASIVE SPECIES. (Remember the other reason?)  These hornets are an invasive species and just a few hornets can destroy an entire honeybee hive. Often people call wasps and hornets “bees,” but they’re very different species.

II.  The Immune System:  There are six types of PATHOGENS …

a.     Viruses (Give an example.)

b.    Bacteria (Give an example.)

c.     Fungi (Give an example.)

d.     Protozoa (Give an example.)

e.     Worms -

f.     Prions -

III.        We’re going to focus on those first four.  Worms get their own category because there are so many types that can cause problems for people and Prions are a recently discovered type of protein that can cause sickness.  We’ve been studying DNA and today it’s about viruses.

IV. Levels of protection:  Sometimes a pathogen gets past the first couple of layers of protection.

a.     Skin

b.    Mucus

c.     Stomach acids

V.    If a pathogen makes it past these, the WHITE BLOOD CELLS are the next line of defense. They patrol the blood and will kill any pathogen they recognize.

VI. Sometimes a new pathogen, that isn’t recognized, will enter the blood stream so white blood cells create ANTIBODIES to fight the infection.

VII.       A PATHOGEN, like a virus, might not be recognized because it has MUTATED: its DNA has changed and it can get by our defenses.

VIII.    This is what has happened with Covid 19. It’s a class of virus we know about, but a new (novel) virus to our species!