Blood - The Tissue of Life
Lesson 18 of 18
Objective: SWBAT identify components of blood and their functions.
To engage students in today' lesson they watch The Components of Blood and Their Importance video (American Society of Hematology). It introduces students to the components of blood.
As students watch video students are required to answer the following questions:
- How many pints of blood in a human body?
- What does blood travel in?
- Where do the blood vessels deliver oxygen to?
- What is the function of the following:
- red blood cells
- white blood cells
Teacher Note: As with any video that introduces science vocabulary it's important that teacher stops video to emphasize main points. One feature that I use in all video is using the Close Captioning feature which displays all words for students to read while listening to video. Students especially EL learners benefit from both seeing and hearing words used in context.
In this section of lesson students develop a model for blood.
Composition of Blood
What do you know about blood? What makes up your blood? How does your blood help your body to maintain homeostasis? (CCC Systems and System Models - Systems may interact with other systems).
In this activity you make a model that represents your blood. This model helps demonstrate the composition of blood and how it functions in your body. (SP2 Developing and Using Models - Develop a model to describe unobservable mechanisms.)
- 2 beakers, 1000 ml (milliliter) or clear plastic containers
- 3 containers, one of which is at least 500 ml (milliliter) in capacity
- Red beans, dried
- White beans, dried, about twice the size of the red beans
- Split peas, dried, about half the size of the red beans
- Yellow food coloring
- Raw egg
- Small pieces of paper towel
- 2 graduated cylinders, 25 or 50 ml (milliliter) and 500 ml
Procedure A: Modeling the Solid Portion of Blood
Step 1 Using graduated cylinders measure the following amounts of dried beans or peas. Then, place the correct amount of each material into a separate container:
A. The red beans represent red blood cells. Measure 425 ml of red beans. Label a container “Red Blood Cells.” Place the 425 ml of red beans into the container marked “Red Blood Cells.”
B. The split peas represent platelets. Label a second container “Platelets.” Measure 22 ml of split peas and place them into the container labeled “Platelets.”
C. The white beans represent white blood cells. Label a third container “White Blood Cells.” Measure 3ml of white beans and place them into the container labeled “White Blood Cells.”
Step 2 Label a 1000 ml beaker “Solid Components of the Blood.” Place all of the beans and the peas into the 1000 ml container labeled “Solid Components of the Blood.”
1) What cells are found in the solid portion of blood?
2) Which from above makes up the largest portion of blood? Why do you think this is?
3) Draw your 1000ml "Solid Components of Blood" beaker in you notebook.
Procedure B: Modeling the Liquid Portion of Blood
Step 1 Using graduated cylinders measure the following amounts of solids and liquids. Then, place the correct amount of each solid or liquid into the correctly marked container.
A. Measure 500 ml of water to represent the water in plasma. Then, place the 500 ml of water into a second clean 1000 ml container. Do not use the 1,000 ml container labeled “Solid Components of Blood.”
B. Label a paper cup “Proteins and Fats.” Place a raw egg into the paper cup. The egg white represents the proteins and the yolk represents the fats in plasma.
C. Label a second paper cup “Minerals, Nutrients, and Wastes.” Salt represents minerals and nutrients. Add a pinch of salt to the paper cup labeled “Minerals, Nutrients, and Wastes.”
D. Yellow food coloring represents wastes. Add one drop of yellow food coloring to the salt to represent the wastes in plasma.
Step 2 Now beat the egg well, so the yolk (fat) and egg white (protein) are mixed. Add the beaten egg to the 1,000 ml container of water. Then add the salt and yellow food coloring to the 1,000ml container of water and beaten egg. All of these materials mixed together represent the liquid portion of blood. Label this container “Blood Plasma.”
DO NOT MIX THE CONTENTS OF THE TWO, 1,000 ml CONTAINERS REPRESENTING THE SOLID AND THE LIQUID COMPONENTS OF BLOOD TOGETHER. THAT WOULD MAKE A MESS!
Step 3 Follow cleanup directions given by your teacher.
- What is used to represent plasma in your model? What characteristics do both plasma and water share?
- What are the other components of plasma?
- Draw your 1,000 "Blood Plasma" graduated cylinder.
In this section of lesson students visit ck-12 to complete a reading activity on blood.
The following topics are covered:
- Blood components
- Functions of blood
- Blood Types
- Blood Diseases
Students are required to answer the following questions after reading:
- What is blood?
- Identify the main function of blood.
- Describe two diseases of the blood and their causes.
- Why might it be necessary to determine your ABO blood type?
- If you have type O blood, which type(s) of blood can you safely receive?
- Compare and contrast red blood cells and white blood cells.
- Relate antigens to blood types.
Points to Consider
The blood picks up oxygen in the lungs and carries it to cells throughout the body.
- How does oxygen enter the lungs?
- How does oxygen get from the lungs into the blood?
In this section we move to a real life application of our understanding of blood - blood types.
The purpose of this activity is to provide students with an understanding of blood types and Rh factors.
1. As a class, visit the following Franklin Institute websites to learn about blood types and Rh factors:
2. Divide the students into small groups. Ask each group to fill in the following chart based on what it has learned about blood types.
CAN RECEIVE FROM
- Type A blood has A antigens. A person with this blood type can receive blood from a person with type A and type O blood.
- Type B blood has B antigens. A person with this blood type can receive blood from a person with type B blood and type O blood.
- Type AB blood has both A and B antigens. A person with this blood type can receive blood from a person with type A, type B, type AB, and type O blood.
- Type O blood has no antigens. A person with this blood type can receive blood from a person with type O blood.
- Type AB blood is considered the universal recipient blood type and type O blood is considered the universal donor blood type.
Time to assess student learning! I do this using a four corner strategy.
Four corners is used with selected response questions to identify groups of students with similar responses to the question asked. Students move to a corner of the room designated to match their response or similar thinking. This strategy provides an opportunity for students to make their ideas public. Furthermore, by meeting in 'the corner" with students who have similar ideas, students can further discuss and clarify their own thinking with others before returning to their seats and engaging in scientific argumentation with the class or small groups of students with different ideas.
1. Label the 4 corners:
- Corner 1 - Red Blood Cells
- Corner 2 - White Blood Cells
- Corner 3 - Platelets
- Corner 4 - Plasma
2. Inform students that you will be asking questions and the answers are found in one of the four corners.
3. Instruct students that they need to choose a corner in response to each question, even if they are not 100% sure about their answer.
4. Once students are in corners they need to discuss with each other why they chose that answer.
Possible Questions can come from the following categories:
- Function of component (example: This cell is responsible for carrying oxygen throughout your body).
- Amount found in blood (example: These cells make up the smallest portion of your blood).