After finishing our study of circulation, we are wrapping up the exploration of the respiratory system this week. While looking at the circulatory system, and in addition to our laboratory activities, the students conducted a dissection of pig and cow hearts. This gave students a hands-on look at the “heart” of the circulatory system and enabled them to later create a working model of a heart chamber. Video of the students in action can be seen by following this link:
We are now beginning to explore the relationship between respiration and circulation in more depth through continued laboratory investigations. The students have already completed separate lab activities looking at the effect of exercise on both heart rate and carbon dioxide production. We are now ready to look at the interconnection of the two systems by observing how a change in one causes a response in the other – through an exploration of the mammalian diving reflex.
The summative assessment for the Systems Unit will take place after the October break. Students will begin developing a scientific investigation of their own creation to demonstrate the relationship between the circulatory and respiratory systems, similar to the examples we have practiced in class. Students will work in small groups to design, carry out the investigation, and collect data. They will then be asked to create graphs and draw conclusions based on this data, discussing how their experiment shows the interconnectedness of the systems. The individual write-up will most likely occur at the beginning of the second week after the break. I will post the specific summative assessment dates on the Walsh – Grade 8 Science website when they become more clear.