Oxygen Highway Workbook
Gas Exchange & Homeostasis
Student Activity Workbook
Name: Per:
Date:
Inside of the lungs are structures (shaped like broccoli) called alveoli that help transport gases into and out of the bloodstream. The bloodstream acts like a highway system to transport oxygen, carbon dioxide, nutrients, and waste to and from all of the cells in your body.
Q1
What gas enters the lungs and bloodstream?
Answer:
Q2
What gas leaves the lungs and bloodstream?
Answer:
Diagram 1 Tasks
Color the solid arrows GREEN (Oxygen).
Write "O₂" next to solid green arrows.
Color red blood cells inside capillary RED.
Color dashed arrows YELLOW (CO₂).
Write "CO₂" next to dashed arrows.
Diagram 1: Alveoli Gas Exchange Alveoli
Red blood cells carry oxygen from the lungs to the cells around the body.
Q3
Where does the red blood cell get oxygen from?
Diagram 2: Red Blood Cell Zoom-In O₂
Diagram 2 Tasks
Label the rest of the blank circles as "O₂".
Color the oxygen molecules GREEN.
Color the rest of the RBC RED.
Oxygen Highway Biology Lesson Portfolio Page 1 of 3
Gas Exchange & Homeostasis
Student Activity Workbook
Name: Per:
Date:
The red blood cell travels through blood vessels to reach cells in other parts of the body. Once it reaches body cells, the red blood cell gives the oxygen to the body cells in order for the cells to do cellular respiration. In addition, it takes any CO₂ waste from those cells to transport back to the lungs.
Q4
What are two reasons body cells need oxygen?
Diagram 3 Tasks
Color left RBC O₂ molecules GREEN, and cell RED.
In right cell, color the CO₂ molecules YELLOW.
Color the 2 mitochondria PURPLE.
Color the O₂ delivery arrow to mitochondria GREEN.
Color the CO₂ waste arrow to RBC YELLOW.
Diagram 3: Cellular Respiration Delivery RBC O₂ O₂ O₂ Body Cell Nucleus Mito Mito CO₂ CO₂
The red blood cell then returns to the lungs with carbon dioxide waste and drops it off (which you breathe out). Then it picks up new oxygen.
Q5
What "waste" does the blood cell drop off at the lungs?
✔ Color the lungs PINK • Blood cells RED
✔ Oxygen arrows GREEN • CO₂ arrows YELLOW
Lung Return
Oxygen Highway Biology Lesson Portfolio Page 2 of 3
Gas Exchange & Homeostasis
Student Activity Workbook
Name: Per:
Date:
Section A: The Balance of Life & Homeostasis
Your cells can only survive if their internal environment stays stable and balanced. This constant balance is called homeostasis. During exercise, your muscle cells work harder and do more cellular respiration to make energy. This process uses up Oxygen (O₂) and produces Carbon Dioxide (CO₂) as a waste gas.
If too much CO₂ builds up, it makes your blood acidic and toxic. To prevent cell damage, your nervous system monitors your blood. When CO₂ levels rise, your brain instantly signals your respiratory system to breathe faster and deeper, exhaling the waste CO₂ and bringing in fresh O₂ to restore healthy chemical homeostasis.
Section B: The Homeostasis Feedback Loop
• Homeostasis • Carbon Dioxide • Brain • Oxygen
1. RESTING STATE Body cells are at rest, maintaining a balanced internal state called
2. STIMULUS (EXERCISE) Active muscle cells burn fuel and produce excess waste gas:
4. FEEDBACK RESPONSE Lungs breathe faster to exhalate CO₂ and bring in fresh:
3. DETECTOR & CONTROL The high CO₂ levels in blood are detected by the:
LOOP
Section C: Guided Analysis Questions
Q6 Guided Fill-in-the-Blanks:
To create ATP energy during exercise, cells perform cellular which consumes gas and generates gas as a waste.
Q7 Homeostasis Explanation:
Breathing faster helps my body cells maintain homeostasis because...
Q8 Predict: What happens if your lungs fail to remove CO₂?
Bank: acidic | toxic | die | fail
If my lungs failed to remove CO₂, it would build up and make my blood extremely . This environment would be to cells, causing them to and causing organ systems to .
Oxygen Highway Biology Lesson Portfolio Page 3 of 3
Oxygen Highway Workbook Answer Key
TEACHER ANSWER KEY
Gas Exchange & Homeostasis Key
Teacher Reference Guide
Name: ANSWER KEY Per: KEY
Date: MASTER
Inside of the lungs are structures (shaped like broccoli) called alveoli that help transport gases into and out of the bloodstream. The bloodstream acts like a highway system to transport oxygen, carbon dioxide, nutrients, and waste to and from all of the cells in your body.
Q1
What gas enters the lungs and bloodstream?
Answer: Oxygen (O₂)
Q2
What gas leaves the lungs and bloodstream?
Answer: Carbon Dioxide (CO₂)
Diagram 1 Key
✔ Solid block arrows colored GREEN and labeled O₂.
✔ RBCs inside capillary tube colored RED.
✔ Dashed block arrows colored YELLOW and labeled CO₂.
Colored Answer Reference Alveoli O₂ O₂ CO₂
Red blood cells carry oxygen from the lungs to the cells around the body.
Q3
Where does the red blood cell get oxygen from?
The alveoli (air sacs) inside of the lungs.
RBC Coloring Key O₂ O₂ O₂ O₂ O₂ O₂
Diagram 2 Key Tasks
✔ All six oxygen molecule circles must be labeled "O₂" and colored GREEN.
✔ The entire rest of the red blood cell must be colored RED.
Oxygen Highway Biology Lesson Portfolio Page 1 of 3 (Answer Key)
TEACHER ANSWER KEY
Gas Exchange & Homeostasis Key
Teacher Reference Guide
Name: ANSWER KEY Per: KEY
Date: MASTER
The red blood cell travels through blood vessels to reach cells in other parts of the body. Once it reaches body cells, the red blood cell gives the oxygen to the body cells in order for the cells to do cellular respiration. In addition, it takes any CO₂ waste from those cells to transport back to the lungs.
Q4
What are two reasons body cells need oxygen?
1. To carry out cellular respiration to produce energy (ATP).
2. To keep the cells alive and functioning properly.
Diagram 3 Key
✔ RBC and body cell elements colored according to check boxes.
✔ Mitochondria colored PURPLE.
✔ Block arrows colored in correctly: Oxygen block arrow is GREEN, Carbon dioxide block arrow is YELLOW.
Cell deliver & waste key Body Cell CO₂ CO₂
The red blood cell then returns to the lungs with carbon dioxide waste and drops it off (which you breathe out). Then it picks up new oxygen.
