The Nerve of Stem Cells! Day 1

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Objective

Students will describe the process of nerve specialization and nervous system development from the stage of embryonic stem cells to early infancy.

Big Idea

Nerve tissues form and function are determined by internal and external factors.

Introduction

Lesson Background & Justification:

Neuroscience is an emerging field of study which encompasses various scientific disciplines that deal with the structure, development, function, chemistry, pharmacology, and pathology of the nervous system. In order for students to authentically appreciate the content of its applied content, the presentation of material in this course must be highly scaffolded and provide opportunities for students to review foundational material prior to its content  introduction. 

In this lesson, students are primed with the basics of the fertilization process prior to the introduction of Stem cell capacities and their role in specializing the nervous tissue studied in our course. This  information strategically precedes the presentation of lessons on neurogenesis & brain development and provides a more generic and functional tier of information which will aid in students content acclimation successes when they encounter more depth and breadth further along the unit. Furthermore, students are introduced to and utilize the concept of Mathematical Modeling to develop their thoughts as more information is presented and grows in complexity.   

Instructor's Note:

This lesson is divided into two ninety minute instructional blocks. Day one, this lesson addresses the Engagement, Exploratory and the Explanation areas of the 5E Model Lesson Plan. The second day addresses the second half of the 5E Model specifically, the Extension and Evaluation activities.

Lesson Preparations:

In the effort to prepare for this lesson, I make certain that I have the following items in place:

 

a) A class set of Science Take-Out's Stem Cells Kit. I obtain one kit for each pair of students.

b) A class set of rulers.

c) Student lab books should be present, but I keep additional blank paper on hand for those who are not prepared to minimize distractions.

 

Common Core and NGSS Standards:


SP4- Analyzing and interpreting data.

SP2- Developing and Using Models.

HS-LS1-4-Use a model to illustrate the role of cellular division (mitosis) and differentiation in producing and maintaining complex organisms.

 

 Standards Rationale:

In the science classroom, students are regularly charged with tasks to collect and make sense of data from readings and investigations. What makes these science experiences powerful enough to retain however, is an instructor's ability to access, stimulate and develop students' higher order thinking capacities for cognitive growth and subsequently establishing sound learning practices. 

In this lesson, students learn to use two different classes of models to build complexity of thought (Mathematical Model) and to build a visual reference for a microscopic process (Simulation Model). Research has shown that modeling is an effective instructional strategy in that it allows students to observe the teacher’s thought processes. Using this type of instruction, teachers engage students in imitation of particular behaviors that encourage learning which on later occasions can later be used to serve as a guide for action. Furthermore, students in conjunction with their modeling systems continue to apply their scientific process skills acquired in lessons 2 & 3 of this course to not only extract and develop significance of data collected, but to mature these habits of mind for long term practices in the classroom.

Engage

20 minutes

Section Primer:

In the engagement part of the lesson, students are introduced to and utilize one example of a Mathematical Model (see examples on slide 1 of the presentation) to articulate their prior knowledge of stem cell function in the human body.  

Section Instructional Sequence:

In this section of the lesson, my goal is to assess students’ prior knowledge on the topic of cell growth, differentiation and bodily systems development beyond the process of fertilization. I use this information to clarify any misconceptions so that students can be more mentally accessible to the information being presented. In doing so, students are also establishing a foundation of knowledge in preparation for learning new information about the skill, topic, or concept. I present this introductory or engagement activity in the following sequence:

a) I proceed to slide 1 of the power point presentation "Stem to Nerve Cells" and read the question from the screen "Who are you?" aloud. As students are generally apprehensive to answer such a vague question, I urge forward and follow up with a second supporting question. I ask, "If you had to summarize who you are using a simple equation or through a mathematical model, what would that representation of you look like? What would be your defining equation?" 

I then advance the examples of mathematical models, one by one on the slide and explain what I mean by mathematical model and the mathematical nature of each. I tell students that I want for them to consider their equations or models specifically from a biological viewpoint (Let's think about who we are biologically). Finally, I state to the class that we will watch a clip and that they should think about how the information presented might help for them to address the question in said fashion. 

b) I then proceed to show the following video which is hyperlinked to the question frame on slide 1. I verbally express to students to consider again how they would define who they are as they watch the following video clip. 

c) Once the video concludes, I verbally instruct for students to define who they are biologically by creating and recording a mathematical model on a large post it note sheet but to use specific terminology that summarizes the variables of choice. (For instance, use the word fertilization as the intended variable as opposed to stating that the egg and sperm unify). I also require that students create areas that are not clear and to use a question mark to signify that more detail is required in that area. The goals are to unearth prerequisite knowledge before using the information fluidly in the lesson and to provide a rough template for students to develop the concept of nervous system development from.  

d) I then ask for student volunteers to display and verbally share their models. I permit 3-5 minutes for this time of sharing.

e) Finally, I instruct the class to hypothesize when nerve cells begin to emerge on their schematics and to highlight that area on their papers with a solid red circle.  

Explore

55 minutes

Section Primer:

Stem Cells are undifferentiated biological cells that can differentiate into specialized cells (ie. nerve cells, epithelial cells, blood cells) and can divide (through mitosis) to produce more stem cells. They are found in multicellular organisms and are classified into broad types: embryonic stem cells, which are isolated from the inner cell mass of blastocysts, and adult stem cells which are found in various tissues. When learning and understanding the mechanisms by which these cells function, we too can understand processes related to neurogenesis and the development of the brain's highly sophisticated topography.

Section Instructional Sequence:

In this section of the lesson, my goal is to give students a hands on experience which simulates how and why stem cells differentiate or specialize in the human body and to infer its significance to the emergence of highly organized structures like our brain. This activity will serve a two-fold purpose in the overarching scaffolding process throughout this lesson. It will 1) Permit students to further grow their Mathematical models generated in the engagement activity and 2) Help students to access a visual on the prerequisite events that occur between fertilization and embryonic development that are not seen in the engagement video. I present this exploration activity in the following sequence:

a) I advance to slide 2 of the presentation and say "We are now going to explore through simulation some of the events that are critical to the development of special systems like our nervous system and hopefully add to our mathematical schematics and fill in some of our gaps of our models as well." 

b) I then hand out a Stem Cell bagged kit (includes student handouts and materials) to every student pair and verbally direct them to not open the bags until they have obtained general directions from myself.

c) I advance to the listed tasks on the same slide and direct student's attention to it. I announce that their jobs are to follow the listed items and to stop where indicated as I point this out on the screen. I continue to explain that specific directions for each part is located on the student sheet inside the bag and they are to use those directions to complete the tasks up until the stopping point. I iterate that they are to record all responses to questions in their lab books under the heading: Stem Cell Exploration Activity

d) Next I give students time to work through the assigned tasks presented on slide 2 but stop for periodic assessments at the prescribed (see times below) stopping points and by posing the following questions:

Task 1/Part 1 (10 minutes): How do we differentiate between Embryonic and Adult Stem Cells?

Task 2/Part 2 (10 minutes): What is a blastocyct? When is it formed naturally in human body? 

Task 3/Part 3-a (25 minutes): What are some potential cellular products of GF's interactions with embryonic stem cells? Which one (s) specifically cultivate nerve cells?

e) Finally, and after the completion of each task, I instruct for students to reexamine their mathematical models and modify it according to their newly acquired content. 

Standards Covered:

SP4- Analyzing and interpreting data.

SP2- Developing and Using Models.

HS-LS1-4 Use a model to illustrate the role of cellular division (mitosis) and differentiation in producing and maintaining complex organisms.

Explain

15 minutes

Section Instructional Sequence:

In this section of the lesson, my goal is to have students compare and contrast their models to another student's mathematical model via a graphic organizer to assess how well a) they themselves comprehend and have illustrated the concept of stem cell activity and b) how well their models correspond to another students. This essentially allows for students to interpret multiple models of the same concept and assesses whether they understand the concept in general. I present this explanatory activity in the following sequence:

a) I advance to slide 3 of the presentation and instruct students to revisit their models and to share if they still have any undefined variables (red circles) in their models. If so, I prompt students to share where their holes are and if they have a prediction to what might be missing. I then allow for discussion of the aforementioned. 

b) I then state to the class that there are some important terms that we all need to include on our models to ascertain similar meaning from model to model. I advance the list of words on the same slide and ask students if they have any of the terms listed on their graphic and if not to insert these terms on their model where it makes sense to. Be mindful that students can add listed words to substitute terms present or can eliminate substitute terms and replace them with the terms listed. 

c) When students have completed task b, I then advance to the next slide (4) and announce that they will now wrap up by comparing and contrasting their models to another student of choice. I point out the graphic on the screen and request for students to record it in their lab books under the title "Explaining Stem Cells". Once students are finished recording their template, I review how the model works on the screen by recording a specific example. I finally instruct for them to partner up to to fill out their charts using information presented on one another's models. 

d) Finally, we close out the lesson with students sharing what they have learned about one another's models and if they thought that they themselves have created an effective model to explain pre, post and actual stem cell activity in fetuses via a discussion format. 

Note: This lesson requires two 90 minute blocks. Students will review the Explain section at the beginning of the subsequent lesson and complete the Extend and Evaluate parts in the thereafter. 

Standards Covered:

SP2-Developing and Using Models.

HS-LS1-4- Use a model to illustrate the role of cellular division (mitosis) and differentiation in producing and maintaining complex organisms.