OpenSciEd Unit 6.6 · Lesson 04 · 4.B
Look for: The blood plasma is a liquid that flows easil…
From Teacher Edition
Facilitation guidance from the lesson plan — what to notice in student thinking and how to respond while teaching.
Building towards
4.B Critically read scientific text to make sense of patterns within structures we observed in the blood related to their function in the body.
What to look / listen for
On the last question of Guidance for Reading about Blood, look for students to respond with any one of the following examples of how structure and function are related in the blood:
The blood plasma is a liquid that flows easily through the blood vessels to move blood cells, nutrients, and so on around the whole body (or throughout the circulatory system).
Red and white blood cells have round shapes. Red blood cells are shaped like a donut without a hole, while white blood cells are shaped more like spheres. Their round shapes allow them to move through blood vessels without getting caught or stuck.
- Red blood cells have a flat, flexible shape that lets them bend so they can fit in small blood vessels.
- Platelets have arms that help them create plugs to prevent blood from leaking out of damaged blood vessels. They do so by sticking to one another and to the sides of a damaged blood vessel.
What to do
If students struggle to answer this question on the handout, first make sure they know the terms “structure” and “function.” You may want to rephrase the question to ask, “What is one way the shape of a blood cell helps it do its job?” You may also want to offer a sentence frame using a specific structure of the blood, such as “The function or job of the platelets is to ________. Their structure or shape helps them do this because ________” Refer students to the images in the reading as well. They may be more comfortable making inferences about the structure/function relationship of the blood parts based on images rather than what they read in the text. Finally, it may help students to consider, “What if the opposite were true?” For example, “What if the blood plasma was really thick and sticky? How would that make it hard to do its job?” or “What if the blood cells were square-shaped? Would they be able to do their job well?”