Week 27b – 03.25 / 03.26 – Thursday / Friday – 2021
- I. Current Events: Weather and Space Junk / Rainforest! (CNN10)
- a.Australia has been trying to recover from devastating fires and now is dealing with floods. (It’s their Autumn right now!)
- b.Newton’s Second Law: Force = Mass x Acceleration – A small object going very fast has tremendous force!
- i.(For Friday) Rainforests have been burned to make room for livestock grazing.
- ii.The RESPIRATORY and CIRCULATORY systems …
- c.OUR atmosphere is about 20 percent oxygen … thanks to PHOTOSYNTHESIS.
- d.RESPIRATION and PHOTOSYNTHESIS are opposite reactions.
- i.Write the reactions here: _______________________
- ii.Muscles, breathing, and our ATMOSPHERE: The human body systems work together.
- e.A MUSCLE called the DIAPHRAGM (“Belly breathing”) is located below the lungs. When it CONTRACTS the lungs expand because air is forced in.
- i.Note: CONTRACTS: That’s all muscles can do! Muscles DO NOT push, they ONLY contract!
- f.WHY is air “forced” in? (Straw demonstration.)
- g.WHY are we bothering to breath in the first place? (Sounds silly at first. BUT … What’s going on?)
- h.The LUNGS (Part of the RESPIRATORY system) exchange the Carbon Dioxide that was in the blood with Oxygen in our atmosphere.
- i.Remember our heart rate experiment? (What was YOUR heart rate? ________ BPM).
- j.This exchange wouldn’t happen without the HEART (Part of the CIRCULATORY SYSTEM) moving our BLOOD (Created by the SKELETAL system) through VEINS and ARTERIES.
- i.(HW) What’s the difference between veins and arteries?
- ii.BILL NYE: Atmosphere: We live at the bottom of an ocean of air!
- k.Death Valley: In CA – Lowest place in the US (On land.)
- i.Air pressure drops as we go higher.
“YouTube” ad (this morning) – Dent extractor using a suction cup … suction is NOT a real force! Why not???(A vacuum doesn’t “suck” – Although, I do suck at basketball - )
Week 27 Reading
Middle School science covers a broad range of topics. Sometimes it’s helpful to work backwards from the concepts we want to understand to where we began. That’s often what we do as we approach the last weeks of school for the semester; see where we’ve been and where we’re going.
Our goal is to have a good foundation for understanding life. That’s a big, complicated subject and we wanted to give some background on how we know what we know (the Scientific Method) and the conditions that make life possible (Earth Science)
The story brought us all the way back to the Big Bang – the time when our universe began. A bit if understanding about light helped us know that our universe probably is about 14 billion years old.
Knowing about the four fundamental (basic) forces of nature helped us get a clearer picture of how “simple” atoms like Hydrogen can combine – through fusion in stars – to make all the heavier elements necessary for life.
By the time our solar system, and Earth, formed – about 4.6 billion years ago, all the elements needed for life were available. Those elements are like the building blocks and cells - the basic units of life - put together and rearrange those building blocks in endlessly complex ways.
When the elements are rearranged, it’s called a chemical reaction, and none is more important than photosynthesis for setting the stage for complex animals.
It took billions of years for the oxygen released into Earth’s atmosphere to build up enough for life to take advantage of this for releasing energy from chemical bonds.
As life evolved from one-celled organisms it diversified into several kingdoms. (Plants, Animals, Protists, Fungi, and Bacteria.) Our branch of this evolutionary tree, the animals, breath the oxygen in our atmosphere and humans are capable of affecting every other branch on the tree of life, which is why we incorporate ecology into our studies.
We spend time learning about our species in detail and try to get a picture of how our eleven body systems work together, and work with our environment, to sustain life. While we study systems and species individually, it’s always with an eye towards the connections between subjects, species, the non-living systems of our planet, and the living system – of which we are a part.