I like a nice big umbrella, arching over the myriad of science concepts, units, standards and vocabulary. I like interrelated, connections, semblance. I like to see the broad so that the specific, the local, the individual topics find one another. There are so many science standards and they are adding more every year. NGSS, Next Generation Science Standards are a great way to bridge the larger science topics. There are seven concepts in NGSS that they call Cross-Cutting Concepts. These concepts have application across all disciplines and spheres of science. Applicable to all grade levels. All academic levels. They are the big umbrella. The seven cross-cutting concepts listed below should not only guide instruction but can be used to provide students with their own umbrella- for them to organize science into relevant, meaningful, purposeful domains so they can find the deep connections that make science personal.
- Cause and Effect
- Scale, Proportion and Quantity
- Systems and System Models
- Energy and Matter: Flows, Cycles, and Conservation
- Structure and Function
- Stability and Change
In this post I will share some ways in which I use these seven concepts to enhance learning in my science classroom. Simple warm-ups, extension activities and just purposeful talk stems are just a few ways these help my students see the big picture, understand that science is everything, everything is connected and if we just pause to analyze our surroundings, reflect on our results- we will remember these concepts. They will become part of our knowledge base not just empty facts and vocabulary.
Patterns are everywhere in nature. Symmetry, the grouping of leaves on a tree, atomic structure just to name a few. There are patterns in the rates of change, in human systems, and in weather, ideas, temperature- its endless. In my classroom I have students decipher which of the seven – one or multiple- concepts our lesson falls under. For patterns they create graphs, charts to organize their data so they can recognize patterns. This gets students connected to empirical evidence, classifications and causality.
Activity- Students collect various leaves from school or their own yards. They are required to take a picture or draw the leaves before they remove them from the plant or tree, or off the ground. Then in class we sort the leaves into groups based on the categories they decide- shape, size, species of flora, and how they were grouped on the tree- dicot or monocot. Then we discuss which grouping had the biggest leaves- where did the plant grow- direct sunlight, shade etc. I want them to see the patterns of leaves, understand why size and shape play a role in photosynthesis. This connects classification, structure and function and macroscopic patterns in nature.
- Cause and Effect: Mechanism and Prediction:
All events have causes they can be simple or complex but understanding the mechanisms that lead one thing to change is important to our understanding of the world around us. Why do leaves change color? Why do we shiver in the cold and sweat in the heat? It is important students understand causality versus correlation. It is important that students can predict outcomes and then perform activities and tasks to collect evidence to support their prediction. Most importantly, it is crucial that students understand that there are multiple causes that can lead to the same result. It’s the relationships between phenomena that makes all the difference.
Activity- A simple activity I use for cause and effect is the cracker test. Every student is given an unsalted saltine cracker. They make a prediction as to what will happens to the crackers taste after they let it dissolve in their mouth -a timer is set for 2 minutes- and during that time they write down the change they notice in the taste. Does it become sour? Sweet? Or does it stay the same? Then we discuss why some students had a sweet taste and why some other maybe didn’t taste a difference. Amylase- the enzyme in our saliva is the culprit. So, if we all have this enzyme why didn’t everyone taste the sweetness that comes from a carbohydrate being broken down into glucose? We discuss chemical properties and well as chemical changes and that everyone has slightly different bacteria and the amount of amylase. As well as simple perception. The results varied based on our unique levels of amylase and our expectation.
- Scale, Proportion and Quantity:
Considering phenomena, micro or macro, understanding proportional relationships and scale are important in science. Seeing different quantities and how they influence effects and changes is an important skill. How much of a dose of medicine do we need? How much of this solvent do we add to this solution before we see a change? Why are cells so small? How much light energy is needed for a plant to convert it into glucose? Using models to identify events impossible for us to witness in the classroom- atomic structure, most of the inside of a cell is a critical way for students to make sense of what seems very limiting and unfathomable.
Activity- My favorite activity at the beginning of the school year is having students create giant cells. Each class has their own cell and each group within the class has an organelle. They make the organelle out of play-doh or something they find inspiring in the makerspace. Then they write a note card to place underneath. The notecard has a description of the structure, why they used the material they did and the function of the organelle. Then all the organelles are placed in the giant cells (on a round table covered with butcher paper). Each class then, in a gallery walk, compares the different cells and identifies what they feel is the best organelle and the best cell model that represents the structure and function of cells. This takes a very abstract idea- cells and makes it interactive.
- Systems and System Models:
Systems, open or closed- human body, weather, space even ecosystems- this is a big concept in Life Science. Systems interact with one-another, some have sub-systems that connect to form a larger complex system. The have inputs and outputs, external forces and internal mechanisms. Using models to represent them is an aspect throughout every field of science. It also needs to be integrated into every science classroom to make sure students can use them to predict the behavior of a system including energy, matter and information flow. The biggest example of this in Life Science in 7th grade is our semester study of human anatomy.
Activity- In my classroom we have a lot of labs and activities for each major human body system. We identify how they are not isolated they are all connected and reliant on one another to reach equilibrium, homeostasis, sustainability. But, my culminating activity for the semester is having students create their own superheroes. They must incorporate 5 body systems and using valid science, explain how their superhero skill or mutation works. They can go fictional with the how, spider bite, falling into toxic waste etc. But they must have real science to explain how they can fly, or have super strength etc. What systems must work together to make this happen? Do their muscles need to increase in size? Does their heart have to pump blood faster, thus larger heart, wider vascular tissue? Students draw they superhero and then write an origin story about their character, incorporating the science behind the mask.
- Energy and Matter: Flows, Cycles and Conservation:
Matter and energy flow in and out of systems is a concept many students struggle with. A natural or designed system transfers energy. This transfer can be tracked. In a closed system it is conserved. Energy as we know can not be created nor destroyed, it just moves between one place and another- between objects, in and out of systems. Cycles are everywhere: water, carbon and of course matter. Yet, this transfer can happen in different ways. This is a key concept in science linking Physics, Chemistry and Biology together. In Life Science we focus on several transferences of energy- chemical to thermal during digestion and decomposition to name just two.
Activity- Decomposition is gross. Its smelly and messy. But it is integral to life. Organic matter breaks down. An activity I love to do in my class is create a compost bin- my science department purchased a set of desktop bins we can set up and allow students to collect data over an extended time. The important thing here is to start it early, put fast decaying, biodegradable matter and keep outside of the bin clean so they can see the action. I usually put a banana peel, apple core, some worms, eggshells, plant leaves and I put some things in that are non- or long-term biodegradable, a Styrofoam cup, wood and a plastic water bottle. As decomposition is happening, we talk about cycles of matter and connect it to the human body and ecosystems.
- Structure and Function:
The way an object is shaped determines its properties and function. If it is meant to roll, it is round to some degree. If it is meant to transfer matter it might be a tube or vascular tissue. Surface area is important. Size is important. The composition and texture is important. If students look at the design and shape of an organelle- they should be able to figure out its function. If we give them a picture of an organ system, they should be able to determine by its layout and how everything is organized- what it does. Different materials have different substructures: The four organic compounds, the elements, minerals etc. It is important to understand composition in order to understand structure and function.
Activity- The giant cell activity is a great way to tie in structure and function. Another way is to have students look deeply at the leaves they collect for the classification, patterns activity and understand why some leaves have larger veins, are shaped in different ways and why usually only succulents store water in such a huge way. But my favorite activity involves pre-ordering a Dyson Engineering Box. They will ship it to you for free with a shipping label for you to forward it on. You get it for two weeks. In the kit are 8 mini vacuums and tools to take it apart and put it back together: tubes, plastic covering, hard outer exterior. As students have fun with engineering, I have them compare this vacuum to the skeletal and muscular system: structure, function and purpose.
- Stability and Change:
Equilibrium and chaos- both happen in nature and in designed systems. Change is measured in in terms of differences over time and students need to understand this may occur at different rates. Some systems appear stable, but over time they will change. Small changes in one part of a system might cause a larger change in another part of the system. Cause and effect. Stability might be disturbed by gradual change or a sudden event. Such as Evolution or a catastrophic event. But if systems are in dynamic equilibrium, they are stable due to feedback mechanisms- such as homeostasis in the body- generally we are stable but internal and external stimuli cause continual responses.
Activity- Stability and change are represented in Life Science in many ways: Natural Selection, Fight or Flight response and succession to just name three. Weathering, Erosion and Deposition are causes for this change in nature, among other factors. I like to bring this, simple concept that most students learned in 6th grade into pop culture. We are always in this unit close to May 4th and so I tie it with Star Wars. I have students research a planet in the Star Wars universe and have them identify an example of W.E.D. and why the planet looks the way it does. I also have them connect it back to patterns, cause and effect and systems. Why is the weather on the planet like it is? What factors play a role in this system- distance from moon, sun etc. Then each group quickly presents a synopsis of their planet and I have them -Look for patterns between planets.
Crosscutting Concepts like these are a great umbrella- a broad domain that can be used to bridge concepts. It is also important that they understand why they are studying the topic in a specific way so throughout the year I have my students identify which crosscutting concept we are using. We discuss why it is important for us to see science from every angle. When students see science as patterns, cause and effect, scale, proportion and quantity, systems and models, energy and matter flow, cycles and conservation, structure and function of objects and stability and change of phenomena- they see science as all interconnected and above all else- themselves as a part of it.