This two day lesson is the students' introduction to the Cells Unit. On Day 1, students are introduced to Cell Theory as they read text through the lens of the NGSS Crosscutting Concepts in order to make deep connections and generate questions they have surrounding the content. Then, students look at living and non living things under microscopes. On Day 2, students support claims with evidence as they write a scientific paragraph.
This lesson is specifically designed to meet the following NGSS and Common Core Standards:
MS-LS1-1 Conduct an investigation to provide evidence that living things are made of cells; either one cell or many different numbers and types of cells.
CCSS.ELA-LITERACY.WHST.6-8.1.B Support claim(s) with logical reasoning and relevant, accurate data and evidence that demonstrate an understanding of the topic or text, using credible sources.
CCSS.ELA-LITERACY.RST.6-8.10 By the end of grade 8, read and comprehend science/technical texts in the grades 6-8 text complexity band independently and proficiently.
Science and Engineering Practices:
The NGSS states that students at any grade level should be able to ask questions of each other about the texts they read, the features of the phenomena they observe, and the conclusions they draw from their models or scientific investigations (SP1). In addition, any education in science and engineering needs to develop students’ ability to read and produce domain-specific text (SP8). In this lesson, when students read text for information and draw connections beyond the text to the cross cutting concepts, they do just that! In addition, students have to write a written argument explaining if they believe a single cheek cell is a unicellular organism (SP7)
Specifically, this lesson ties to the idea that that phenomena that can be observed at one scale, may not be observable at another scale. As students recognize that cells may become visible with the use of a microscope, they are able to connect to this idea of Scale, Proportion, and Quantity.
In addition, his lesson allows the students the opportunity to connect to all of the CCC's. As they read, students make connections to each category and post their connections on sticky notes on a large class graphic organizer.
As this is the first day of the unit, provide students with their Cells Unit Plan. Explain that today is an exciting day because the students' focus changes. With a new unit comes a new Essential Question. Remind them that this EQ will be their focus for each lesson during the unit.
So, each day when they cross the threshold into my classroom, I ask them, "What are you going to learn today?" Students should always refer to this EQ as their focus. Explain that the new EQ for the Cells Unit is, "How do cells contribute to the function of living organisms?" Show students that this EQ is easily available for reference both on the front board and on their Unit Plan. Remind the students that the skills listed on the unit plan are the targets they have to meet in order to reach mastery.
Let students know that today's lesson will focus on Skill 1:
"I can provide evidence that organisms are made of a single cell or many cells.".
Have students silently read the skill along with the bulleted list below the skill and then give themselves a self-assessment score of where they feel they are at in their learning to begin this unit. Students rank themselves on a scale of 1 - 4 (4 being mastery). Explain to students that as this is the first day of the unit, there is nothing wrong with them feeling as if they are at a 1 or a 2. We will build mastery each day!
As an exit ticket, have students complete the Formative Assessment slip. Before the next class, sort the formative assessment slips into stacks of similar learners. In the following day's lesson, I meet with these groups to provide specific instruction geared towards specific student needs.
This student includes some important elements required for mastery:
**Caution: Even with students that show mastery such as this, a follow up conversation needs to be had. Many students begin forming the idea that living things are made of cells while nonliving things are made of molecules. They can have the misconception that living things are not made of molecules.
On Day 1 of this lesson, students looked at living and non living things under a microscope and read text about the Cell Theory while connecting to the NGSS Crosscutting Concepts.
During Day 2 of this lesson, provide students with time to complete their lab document. Below is a look at some student work and some important aspects that students should include in each of the three questions.
In the first question, here are some criteria to look for:
In the second question, the students identify that their diagram demonstrates part one of the cell theory, "All living things are made of cells."
The last question asks students to write an ABCDE paragraph answering the question, "Is a single cheek cell a unicellular organism?". Some aspects to look for in the ABCDE paragraph include:
A - Assertion: The student makes a claim that a cheek cell is not a unicellular organism. (There will be students that claim that it is because it is only one cell.)
B - Background: The student provides the reader with background with what they did in the lab. Background also could simply be, "Unicellular organisms are made of one cell while multicellular organisms are made of many cells." The background gives the reader information that will help them understand the reasons the writer is about to provide.
C - Citation: The student cites a specific text explaining that the text says that a cell from a unicellular organism performs "every function to keep the organism living".
D - Discussion: The student effectively discusses by connecting the citation to the assertion. She explains that "A cheek cell is not a unicellular organism because that one cell can't function on its own to keep an organism alive."
E - End: The student includes a conclusion sentence.
For more detailed information about ABCDE paragraphs, check out the Quick Guide to the ABCDE Paragraph in the resource bin.
While students work on the writing in their lab document, call conference groups based on the stacks of learners you sorted from the formative assessment/exit ticket from the previous lesson (Check out the previous day's formative assessment for more insight.). With this formative assessment, I meet with every student in a group. Even students who earn a "4", or mastery, on their exit slip can have a misconception about what living things are composed of. Thus, with each group, I address their individual, specific needs as well as go through the following card sort activity to confirm their understanding of the target skill: All living things are made up of one or many cells.
Middle school students instinctively have the following thought process that leads to misconceptions:
Living things are made of cells. ~ Nonliving things are made of molecules. ~ Therefore, living things are not made of molecules.
Watch the video below to see how a quick conference in small groups can help quickly clarify this misconception:
In addition, when conferencing with groups, I have students graph their formative assessments on their Working Towards Mastery List. This is a way that they document the specific feedback by skill that they receive with each formative assessment.
As an exit ticket, have students complete the Formative Assessment. As with the previous day's exit slip, sort the student work into groups of similar learners and conference with them in a future lesson
This student recognizes that a unicellular organism carries out all of the functions to support life, while a cell from a multicellular organism could not support itself. One important note is that it is no coincidence that the student used this wording. Each day we continue to refer to the Essential Question, "How do cells contribute to the function of living organisms?". Thus, the students constantly have that goal in their mind. This student even chose to connect to those words "functions to support life".
One group of students that I tend to meet with after this formative assessment are students that write something like, "It would die if it was multicellular. It would live if it is unicellular." While these students have a basic idea that unicellular organisms live on their own, this does not convey the full understanding that unicellular organisms can perform all of the functions to support life.
Again, when you meet with student groups in a future lesson, have them add to their "Working Towards Mastery List" and graph their level of mastery on the skill.