Flow of Matter and Energy in Ecosystems

Biology - Fall 2025
Carrying Capacity
Flow of Matter and Energy in Ecosystems
Scientific Lab Report
Carbon and the Earth (part 1)
Chemistry Review
Cellular Energy and the Atmosphere
Carbon and the Earth (part 2)
Do Now
Take 2-3 minutes to brainstorm. List as many as you can in your journal. Be ready to share.
A.
B.
C.
D.
What factors would impact life in the different ecosystems below? Think of both natural and human influence.
Carrying Capacity How Much Is Too Much?
An exploration of how ecosystems maintain balance through population limitations.
Learning Goals
Standards:
HS-LS2-1: Analyze and interpret data to provide evidence for the effects of resource availability on organisms and populations of organisms in an ecosystem.
HS-LS2-2: Use mathematical representations to support and revise explanations based on evidence about factors affecting biodiversity and populations in ecosystems.
SWBAT:
1
Define carrying capacity and describe its relation to resource limits.
2
Identify biotic and abiotic factors that impact population size.
3
Interpret data and apply reasoning to explain how populations grow, stabilize, or decline.
Investigative Phenomena

Loading...
What prevents organisms from reproducing an unlimited number of offspring?
Graphic Organizer
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Device Island Survivor Game
On Device Island, your group will manage limited resources and make critical decisions to ensure the survival and growth of your population.
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Exit Ticket: Device Island
1. What patterns did you notice?
Think about how your signal changed over time.
2. What factors helped or your population grow?
Consider the events that boosted your signal.
3. What factors limited your population?
Which events caused your signal to drop?
4. What if a new species arrived?
How might that impact the existing devices?
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Do Now (5 minutes)
1. Complete pre-reading worksheet
2. Review Vocabulary 1-8
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Explore 1 Vocabulary
1
Ecosystem
The biotic and abiotic factors in a defined area interacting
2
Biotic
Living, or produced by living things
3
Abiotic
Not living, or produced by nonliving things
4
Carrying Capacity
The maximum number of organisms an ecosystem can support
5
Limiting Factor
Any environmental condition that restricts the growth of a population
6
Organism
A single, self-contained entity that performs all of the basic functions of life
7
Population
All of the organisms of one species within a particular ecosystem
8
Resource
A source or supply that can be used to benefit organisms
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What Is an Ecosystem?
An ecosystem is a functional unit made up of biotic organisms and abiotic factors interacting with each other within a defined area.
Biotic Factors
Living, or produced by living things
Animals
Plants
Single-celled organisms (e.g. bacteria)
Abiotic Factors
Not living, or produce by nonliving things
Air
Temperature
Soil
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What biotic and abiotic factors can you identify in these images?
A.
B.
C.
D.
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Ecosystem Levels of Organization
Organism
A single, self-contained entity that performs all of the basic functions of life
Population
All of the organisms of one species within a particular ecosystem
Community
All of the interacting populations in an area
Ecosystem
The biotic and abiotic factors in a defined area
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Match examples with the correct level of organization
A.
B.
C.
D.
WORD BANK: Organism, Population, Community, Ecosystem
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Answer:
A. Ecosystem
B. Population
C. Organism
D. Community
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What Is Carrying Capacity?
Carrying capacity is the maximum number of organisms an ecosystem can support over time.
Limiting Factors
any environmental condition that restricts the growth, abundance, or distribution of a population within an ecosystem
1
Density-Dependent
Factors related to population size:
Competition for resources
Predation intensity
Disease spread
2
Density-Independent
Factors unrelated to population size:
Natural disasters
Extreme weather events
Climate change
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Explore 1: Factors Affecting Carrying Capacity
Today, you’ll explore what causes populations to grow, slow down, and level off.
Your Mission:
Read the introduction and instructions carefully.
Complete each graph using the descriptions provided.
Use the data and prompts to think about what might cause population growth to change.
Record your ideas and evidence in your journal
Think: What patterns do you notice? What might be limiting growth?
What do organisms need to survive?
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Explore 1: Factors Affecting Carrying Capacity
Read the 2nd paragraph
Why do you think the initial growth rate is slow?
What does it mean for growth to become exponential?
Why do you think the population growth rate eventually slows down and levels off?
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Population Growth
Exponential Growth
Occurs under ideal conditions with unlimited resources.
Population increases rapidly, forming a J-shaped curve.
Often seen in new environments or after a disturbance.
Logistic Growth
Occurs when resources become limited as population grows.
Growth slows as it approaches the carrying capacity.
Forms an S-shaped curve, stabilizing at carrying capacity.
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Homework
Check Google Classroom
Due Monday, September 15th at the start of class
Email me if you need help.
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CER
Out of all the factors discussed in this lesson, which one do you think has the largest effect on the carrying capacity of a pond? Would your answer change if we were looking at an ocean?
Claim
State your position clearly
Evidence
Support with data and facts
Reasoning
Connect evidence to claim
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Investigative Phenomena
What prevents organisms from reproducing an unlimited number of offspring?
Graphic Organizer
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Do Now
Imagine a population of deer living in a forest.
What are 3 biotic factors and 3 abiotic factors that could affect the deer population?
1.Choose two of your answers and explain how they would increase or decrease the number of deer.
2.Example: If there's more shelter, what happens? If predators increase, what happens?
Take 5 minutes to jot down your response in your notebook.
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Limiting Factors in Ecosystems
Boundaries
The available space or habitat size for a population.
Resources
The availability of food, water, and shelter for organisms.
Climate
Environmental conditions like temperature, rainfall, droughts, and storms.
Competition
Rivalry among individuals or species for limited resources.
Think: Which limiting factor do you believe has the most significant effect on deer populations in New Jersey, and why?
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Explore 2 Vocabulary
1
Niche
the ecological role played by an organism
2
Species
a group of organisms that can interbreed to generate fertile offspring
3
Interdependent Relationship
a relationship in which two organisms are mutually dependent on each other to survive
4
Predation
an interaction between organisms in which one organism captures and consumes another organism
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Explore 2 Vocabulary
1
Competition
a condition that occurs when two or more organisms compete for the same resources within an ecological community
2
Commensalism
a symbiotic relationship where one organism benefits and the other is neither harmed nor helped
3
Mutualism
a relationship between organisms or species that is helpful to both
4
Parasitism
the symbiotic relationship in which one organism benefits while the other is harmed
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What is a Keystone Species?
Definition
A species that has a disproportionately large effect on its natural environment relative to its abundance.
Its removal significantly alters the ecosystem.
Example: Sea Otter
Sea otters are crucial predators of sea urchins. Without otters, urchin populations explode, decimating kelp forests.
Kelp forests provide food and shelter for many other species, so their loss impacts the entire ecosystem.
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Types of Relationships
Organisms within an ecosystem are constantly interacting. These relationships are crucial for maintaining balance.
Competition
Organisms vie for limited resources like food, water, space, or mates.
Predation
One organism (predator) hunts and consumes another (prey) for energy.
Symbiotic Relationships
Close, long-term interactions between different species, in which at least one of the organisms benefit from the relationship.
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Symbiosis Examples
Mutualism
Both organisms benefit from the interaction.
Ex: Clownfish & Sea Anemone
Clownfish get protection; anemones get food scraps and water circulation.
Commensalism
One organism benefits, while the other is unaffected.
Ex: Barnacles & Whales
Barnacles hitch a ride to food-rich waters; whales are unaffected.
Parasitism
One organism (parasite) benefits, while the other (host) is harmed.
Ex: Tapeworm & Human
Tapeworm absorbs nutrients; human loses nutrients and may get sick.
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Quick Check: Identify the Relationship Type
1
Acacia Tree & Ants
Ants live in the thorns of an acacia tree, protecting it from herbivores. The tree provides nectar and shelter to the ants.
What type of relationship?
2
Mosquito & Human
A mosquito feeds on a human's blood. The human experiences an itchy bite and may contract diseases, while the mosquito gains nutrients.
What type of relationship?
3
Hawk & Rabbit
A hawk swoops down to catch a rabbit for its meal. The rabbit attempts to escape but is consumed by the hawk.
What type of relationship?
4
Gorillas & Territory
Two male gorillas fight to determine dominance and control over a foraging territory within their habitat.
What type of relationship?
Choices: Competition, Predation, Mutualism, Commensalism, Parasitism
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Quick Check: Identify the Relationship Type (Answer)
1
Acacia Tree & Ants
What type of relationship? Mutualism
Why? Both organisms benefit. The ants gain food and shelter, while the tree gains protection from herbivores.
2
Mosquito & Human
What type of relationship? Parasitism
Why? The mosquito benefits by feeding on the human’s blood, while the human is harmed (itchy bite, possible disease).
3
Hawk & Rabbit
What type of relationship? Predation
Why? The hawk (predator) hunts and consumes the rabbit (prey), which is harmed/killed in the interaction.
4
Gorillas & Territory
What type of relationship? Competition
Why? Both gorillas are competing for the same resource (territory). Neither benefits directly, and one will eventually dominate.
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Can you see a pattern?
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Can you see a pattern?
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Intro to Graphing – Measuring Carrying Capacity
We understand the factors that limit populations – resources, space, climate, and competition. But how do scientists precisely measure and track these limits?
The answer is simple: Graphs.
Graphs turn numbers into pictures so we can see patterns.
Scientists use graphs to study patterns, cycles, and limits that are hard to see in data tables.
Today, you'll learn how to create and effectively interpret graphs.
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Types of Graphs
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Choosing the Right Graph
Selecting the appropriate graph type is crucial for effectively communicating scientific data. Each type serves a distinct purpose in highlighting specific trends or comparisons.
Line Graphs
Ideal for visualizing changes over time, making them perfect for tracking population growth or decline, and observing predator-prey cycles.
Bar Graphs
Best used for comparing distinct categories or groups, such as the number of individuals in different species or the varying impact of different limiting factors.
Pie Charts
Excellent for illustrating parts of a whole or percentages, like the proportion of different organisms in an ecosystem or the distribution of resources.
Understanding these distinctions helps ensure your data tells the clearest and most accurate story.
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Key Elements of a Graph
Title
Write what the graph is about.
Example: Plant Growth Over Time
X-axis (Horizontal)
Independent variable: what is changed
Example: Time (weeks)
Y-axis (vertical)
Dependent variable: what you’re measuring
Example: Height (cm)
Units & Scale
Units are placed in parentheses and are found in x and y axis titles.
Data Points
Match corresponding x and y-values (x,y).
Ex: Week 3, Height 10 → (3, 10)
Connect Points
Connect the dots with a line to show the trend.
Key / Legend
If more than one set of data, use different colors or labels.
Ex: Blue = Low Light, Red = High Light.
Scale
Establish an even, consistent numerical scale along both axes.
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Graphs do not have meaning, until we give it one.
Graphs are more than visuals—they tell a story about the natural world.
Scientists use interpretation to provide meaning.
Example Questions:
Is the population going up, down, or staying the same?
Does one line change before another?
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Interpreting Graphs: Look for Overall Trends
Direction of Change
Is the line increasing, decreasing, or staying flat over time? This indicates growth, decline, or stability.
Repeating Patterns
Does the line exhibit a cyclical or oscillating pattern? This often points to seasonal changes or recurring events.
Extrema Points
Are there clear maximum (carrying capacity) or minimum points? These can signify limits, peak activity, or critical lows.
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Overall Trends Continued
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Interpreting Graphs: Comparing Variables
Graphs often display multiple variables, allowing us to analyze how changes in one affect the others. This helps uncover cause-and-effect relationships or sequential patterns.
Direct Relationships
When one variable increases, the other typically increases as well, or vice versa. They move in the same general direction.
Ex: As light increases, plant growth increases.
Inverse Relationships
As one variable increases, the other decreases. They move in opposite directions, indicating a negative correlation.
Ex: As competition for resources increases, population growth rate decreases.
Lagging Effects
Changes in one variable are followed by changes in another, but with a delay. This is common in ecological cycles.
Ex: When prey populations increase, predator populations increase shortly after.
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Comparing Variable Continued
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Anomalies in the Data
Sometimes graphs show data points that don’t follow the usual trend. These “anomalies” can be just as important as the main pattern.
1
Spotting Deviations
Does any data point NOT fit the overall trend or expected pattern?
2
Understanding Outliers
Scientists call these peculiar data points "outliers."
They can either reveal new insights or signal a need for further data collection or review.
3
Investigating Causes
What might explain these unexpected readings?
Consider: external factors, environmental changes, or even measurement errors.
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Examples of Analysis: Explaining Why
Cause and Effect
Analyze if changes in one variable directly influence another.
Look for direct links where one event triggers a subsequent change.
Example: A severe drought (cause) often leads to a significant decrease in local animal populations (effect) due to resource scarcity.
Predator-Prey Cycles
Observe the cyclical fluctuations between predator and prey populations.
An increase in prey typically precedes an increase in predators, followed by a decline in prey.
Example: When rabbit populations rise, fox populations often increase shortly after. This increased predation then causes a drop in rabbit numbers.
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Connecting Back to Science
After analyzing the data and interpreting graphs, the most critical step is to bridge your findings back to the core scientific questions and real-world implications.
Beyond the Numbers
Don't just describe what the graph shows; explain what it means.
Ex: How does this relate to carrying capacity or limiting factors?
New Questions
Every conclusion often leads to new inquiries.
Use your findings to propose further investigations or refine existing hypotheses.
Broader Impact
Consider the real-world significance.
How do they contribute to our understanding?
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Explore 2: Hare and Lynx Populations
How do you think carrying capacity is measured?
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Explore 2 Wrap Up
Imagine you are a scientist and have just learned that all the natural predators of sheep were removed from the area. Within a few years, the sheep population increased tremendously, and within the next several years, the population collapsed to a very small number.
Formulate a hypothesis that might explain the increase and decrease of the sheep population related to carrying capacity.
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Scale Matters
Small Ecosystem
Easily disrupted by changes.
A single drought can severely impact many organisms.
Large Ecosystem
More stable and resilient.
Requires bigger, more widespread changes to significantly affect populations.
The impact of limiting factors varies significantly with the scale and resilience of the ecosystem.
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Biodiversity Keeps Ecosystems Stable
What is Biodiversity?
The variety of life within an ecosystem, encompassing the diversity of genes, species, and ecological processes.
Enhanced Resilience
Ecosystems with greater biodiversity are better equipped to absorb and recover from disturbances, making them more resilient to limiting factors.
Increased Vulnerability
Lower biodiversity reduces an ecosystem's capacity to adapt, increasing its susceptibility to collapse when faced with environmental changes or threats.
Why do you think ecosystems with more biodiversity are better at handling change? What would happen if we lost too many species from the food web?
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Investigative Phenomena
What prevents organisms from reproducing an unlimited number of offspring?
Graphic Organizer
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Homework (9/22)
1. Complete Read pgs 9- of the STEMcopedia
2. Answer the questions at the end of the reading
3. Complete 6 and 7 on the Anticipation Guide
4. Complete classwork
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Key Vocabulary
Abiotic
Adaptation
Biotic
Boundary
Carrying Capacity
Climate
Commensalism
Community
Competition
Ecosystem
Emigration
Exponential Growth
Immigration
Interdependent relationship
Keystone species
Limiting Factor
Logistic Growth
Mutualism
Niche
Organism
Parasitism
Population
Predation
Resource
Species
Symbiotic
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Writing a Scientific Lab Report: The Duckweed Experiment
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Elements of a Scientific Lab Report
1
Introduction
State the purpose, background information, and hypothesis of your experiment.
2
Materials & Methods
Detail all equipment used and precisely describe the step-by-step procedures.
3
Results
Present your collected data, observations, and any graphs or tables clearly.
4
Discussion
Analyze your results, explain their significance, and discuss any errors or future considerations.
5
Conclusion
Summarize your key findings and determine if your hypothesis was supported.
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Duckweed Population Growth Experiment
Research Question: What happens to a plant population when it grows without predators or competition?
We will grow duckweed in containers for 2–3 weeks.
Goal: Observe how the population changes over time.
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Background: What is Duckweed?
Duckweed is a small aquatic plant that floats on ponds, rivers, and lakes.
It looks like green “scum,” but is really made of many tiny plants.
It can reproduce by seeds but usually reproduces asexually.
A new plant grows off the old one, develops roots, and then separates.
Population growth is measured by counting the number of thalli (plant bodies).
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Why Duckweed?
Fast life cycle = population grows quickly.
Easy to see growth over days/weeks.
Safe, hands-on way to study population growth.
Helps us understand:
Exponential growth
Carrying capacity
Competition
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Formulating Your Hypothesis
As a group, decide what shape (J or S-shaped) you think the duckweed growth curve will look like.
Draw the expected shape in your notebook and write a short explanation for your choice, considering what you know about duckweed and its environment.
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Materials
10-oz cup with pond water
Forceps
2–3 duckweed plants
Magnifying glass
Light source (lamp, window, or greenhouse light)
Miracle Grow solution
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Methods
1. Prepare Your Container
Fill your container with ~250 mL of pond water.
2. Introduce Duckweed
Carefully add 2–3 duckweed plants to the water using forceps.
3. Add Nutrients & Record
Add Miracle Grow solution and precisely record the amount you add to ensure consistent experimental conditions.
4. Initial Observation
Sketch and label your duckweed setup in your notebook before placing it on the window ledge.
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Methods continued
5. Set Up Light Source
Place your container under a consistent light source (window).
6. Daily Counting
Count and record the number of duckweed plants daily for 8–10 days.
7. Data Analysis
Organize your collected data into a table and create a graph to visualize your results.
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Data Collection
Accurate data collection is the backbone of any good scientific report. Use the table below as a template to record your daily duckweed plant counts and any relevant environmental observations throughout the experiment.
Remember to be precise with your counts and detailed in your observations—these details will be critical for your analysis!
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Results: What to Include
The Results section of your lab report is where you present the data you collected without interpretation.
01
Data Table
Present your organized duckweed counts over the experimental period in a clear, labeled table.
02
Graph
Visually represent your data using the appropriate graph type (e.g., line graph for population growth over time).
03
Observations
Describe any patterns, significant changes, or interesting occurrences you observed during the experiment.
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Discussion
The discussion section is where you interpret your results, explain their significance, and reflect on the experiment's strengths and limitations. Use these questions as a guide:
What happened to the duckweed population over time?
Describe the overall trend of the duckweed population over time. Did it increase, decrease, or remain stable?
Where was growth fastest? Slowest?
Identify specific periods where the duckweed population experienced its fastest and slowest growth. Provide possible reasons.
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Discussion continued
Were there times of no growth?
Did you observe any periods of no growth or even a decline? What environmental factors might explain this?
What could explain your results?
Connect your observations and data to biological principles, such as limiting factors or carrying capacity. What inferences can you make?
What errors or problems may have affected your results?
Consider any sources of error or problems that might have influenced your results. How could these be minimized in future experiments?
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Conclusion: Summarizing Your Findings
The final section of your lab report is where you bring everything together, concisely stating what you found and what it means.
Restate Hypothesis
Clearly restate your initial hypothesis about the duckweed population growth curve.
Supported or Not?
State unequivocally whether your data supported or did not support your hypothesis.
Explain with Evidence
Use specific quantitative data and refer directly to your graph to justify your conclusion.
Future Directions
Propose new questions or experiments that could be conducted based on your findings.
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Introduction to Invasive Species
Phenomena Question
What happens when a new species enters an ecosystem without natural predators or competition?
What are Invasive Species?
These are non-native organisms that spread quickly and often harm native plants, animals, and entire ecosystems.
Today, we'll connect we learned from duckweed to real-world invasive species.
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Case Study: Brown Tree Snake
What is meant by the term invasive species?
Why is the brown tree snake considered an invasive species?
How does the brown tree snake end up in new environments?
What threats does the brown tree snake pose to naturally occurring species in these new environments?
Why does the brown tree snake population thrive in new environments? What adaptations does the brown tree snake have that help it thrive?
Watch Video: PBS Biological Invaders (3:23)
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Case Study: Leafy Spurge
Where does leafy spurge come from?
Why is it a problem?
How does the leafy spurge adapt to survive in new environments?
How is the leafy spurge controlled in its natural environment and in new environments?
What potential problems could arise from controlling the population of leafy spurge, as seen in the video?
What adaptations in leafy spurge are similar to the adaptations you identified in duckweed?
Watch Video: PBS Leafy Spurge (4:43)
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Group Activity – Be the Ecologists
As a team of local ecologists, your critical mission is to devise a comprehensive proposal for managing and controlling duckweed populations in your community's aquatic ecosystems. This proposal will be presented to the class for discussion.
Identify Sources of Invasion
Investigate the most probable routes of duckweed introduction into your local waterways, considering factors such as recreational boating, improper disposal of aquatic plants, and natural dispersal mechanisms.
Analyze Favorable Conditions
Examine specific environmental factors in your area, such as nutrient levels from runoff, water temperature, and water flow characteristics, that contribute to the rapid proliferation of duckweed.
Propose Prevention & Control Strategies
Develop concrete and actionable strategies to prevent further duckweed entry and effectively manage existing populations. This should include community education initiatives, physical barriers, or biological controls.
Be prepared to present your team's proposal and engage in a class debate regarding the advantages and disadvantages of each suggested approach.
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Ecologist Challenge: Your Proposal
As a team of ecologist, your job is to develop a proposal for controlling the duckweed population in pond at Cadwalader Park. In your proposal, include the following information:
What are the possible sources of the duckweed?
How can the duckweed be prevented from entering your area?
What are the environmental conditions in your area that allow the duckweed to grow so rapidly?
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Lesson Resources & Links
Digital Textbook
Explore Carrying Capacity on STEMScopes.
Missed Class?
Run your own population experiments with our online carrying capacity lab simulator.
Supplemental Videos
Watch engaging documentaries on keystone species and ecosystem resilience.
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Do Now
The following objects are part of a food chain. How would we draw arrows to show the flow of energy? 
Complete the energy flow diagram (on the left) and fill in the paragraph in your journal.
Time: 5-7 minutes
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Flow of Matter & Energy in Ecosystems 
Understanding the intricate pathways through which vital resources move and transform within natural systems.
Learning Goals
Standards
HS-LS2-3: Construct and revise an explanation based on evidence for the cycling of matter and flow of energy in aerobic and anaerobic conditions.
HS-LS2-4: Use mathematical representations to support claims for the cycling of matter and flow of energy among organisms in an ecosystem.
HS-LS2-5: Develop a model to illustrate the role of photosynthesis and cellular respiration in the cycling of carbon among the biosphere, atmosphere, hydrosphere, and geosphere.
SWBAT:
1
Trace the flow of energy through producers, consumers, and decomposers in an ecosystem by creating and analyzing diagrams such as food chains, food webs, and energy pyramids.
2
Explain how matter cycles through Earth’s systems (biosphere, atmosphere, hydrosphere, and geosphere) and describe why matter is conserved in an ecosystem.
3
Interpret and use energy pyramids to calculate how much energy is transferred from one trophic level to the next, and explain why energy decreases as it moves through an ecosystem.
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Investigative Phenomena


Organisms are only able to obtain about 10% of the energy available from the trophic level below it. What evidence supports this fact?
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Graphic Organizer
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Energy Flow Domino Game
In pairs, arrange dominoes representing the Sun, producer, primary consumer, secondary consumer, and tertiary consumer.
Place small arrows between each domino to indicate the direction of energy transfer.
Push the "Sun" domino to observe the cascading effect as energy transfers through the chain.
Combine with other groups to link multiple food chains, forming a complex food web to visualize interconnected energy flow.
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Debrief: Energy Flow Domino Game
1. What did you observe when you pushed the first domino?
2. How does this activity model energy flow in an ecosystem? 
3. What did the numbers on the organism cards represent? 
4. How was energy transferred to the environment? What type of energy was it?
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Exit Ticket (10 minutes)
Jot down at least 3 points in the Before Instruction of the Investigative Phenomena worksheet 
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Do Now
1. What is the source of the energy in the ecosystem pictured? 

2. What steps does the energy flow through in this picture?




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Explore 1 Vocabulary
Biomass
A form of renewable energy source from living or once living plant and animal materials that is often used as fuel
Consumer
An organism that must consume other organisms for nutrients
Decomposer
Organisms such as bacteria and fungi that break down the remains of dead plants and animals without need for internal digestion
Detrivore
An organism that feeds on dead or decaying plant or animal remains
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Explore 1 Vocabulary
Matter
Anything that has volume and mass
Producer
An organism that is capable of performing photosynthesis, transforming energy from the Sun, and using carbon dioxide and water to make food
Photosynthesis
the process by which plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar
Chemosynthesis
the process where organisms use chemical energy from carbon dioxide, hydrogen sulfide, and oxygen to produce the carbohydrates they need for life 
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Review: Building Blocks of Life
1. Which of the following is the smallest unit of life?
A. Tissue           C. Organ 
B. Cell               D. Organism
2. A group of similar cells working together to perform the same function is called a:
A. Population         C. Tissue
B. Organ                 D. Community
3. Which level includes different species living together in the same area?
A. Organism          C. Community
B. Population        D. Ecosystem
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Review: Levels of Biological Organization
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What is Matter?
Matter is anything that has mass and takes up space. 
Made of atoms (elements like C, H, O, N, P, S) 
All living and nonliving things are matter
Ex: rocks, air, water, plants, YOU
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The Law of Conservation of Matter
1. Matter cannot be created or destroyed

2. It only changes form or moves between places

3. Same atoms on Earth today as billions of years ago!
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Quick Check: True of False
1. Matter can be created if enough energy is added. 
2. Matter cannot be destroyed; it only changes form.
3. When wood burns to ash, the matter completely disappears.
4. The atoms in your body today have existed on Earth for billions of years. 
5. In ecosystems, matter cycles between living and nonliving parts. 
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Quick Check: True of False
1. Matter can be created if enough energy is added. (False)
2. Matter cannot be destroyed; it only changes form. (True)
3. When wood burns to ash, the matter completely disappears. (False)
4. The atoms in your body today have existed on Earth for billions of years. (True)
5. In ecosystems, matter cycles between living and nonliving parts. (True)
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Do Now: Research - What Makes the World Go Round? (2.1 Explore 2)
Research your assigned sphere with your partner
1.Research the following questions
2.How do the two spheres you were given interact?
a.What is a specific example of their interaction?
b.How is carbon exchanged between the two spheres to maintain life?
c.What other information do you believe is important or interesting about these two spheres?
3.
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Earth's Four Spheres (Overview)
Biosphere
All living things (plants, animals, microbes)
Hydrosphere
All water (liquid, solid, vapor)
Atmosphere
gases around Earth 
Geosphere
Rocks, soil, and land

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Biosphere
The sum of all the life on Earth

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Hydrosphere
All water on Earth, including oceans, surface water, groundwater, and glaciers

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Atmosphere
The whole mass of air surrounding Earth; made up of 78% nitrogen, 21% oxygen, and other trace gases

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Geosphere
The portion of the Earth system that includes Earth's interior, rocks and minerals, landforms, and the processes that shape Earth's surface

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Essential Elements: CHONPS
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Essential Element: Carbon (C)
The backbone of life → found in all organic molecules.
Where: 
Atmosphere (CO₂)
Biosphere (sugars, animals)
Hydrosphere (dissolved CO₂)
Geosphere (fossil fuels, rocks)
Moves by: Photosynthesis, respiration, decomposition, combustion
When you breathe out, which form of carbon are you releasing
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Essential Element: Hydrogen (H)
Found in H₂O (water) and in molecules like glucose; needed for life reactions.
Where: 
Hydrosphere (H₂O)
Biosphere (in all cells, and compounds)
Atmosphere (water vapor) 
Moves by: Water cycle (evaporation, condensation, precipitation), photosynthesis, and respiration
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Essential Element: Oxygen (O)
Needed for respiration; part of water (H₂O),  carbon dioxide (CO₂) and organic compounds
Where:
Atmosphere (O₂ , CO₂)
Biosphere (used by organisms, release by plants)
Hydrosphere (dissolved oxygen for aquatic life)
Geosphere (in rocks and minerals)
Moves by: Photosynthesis, respiration, decomposition
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Essential Element: Nitrogen (N)
A key part of amino acids (building blocks of proteins) and nucleic acids (DNA & RNA).
Where:
Atmosphere (78% N₂ gas!)
Biosphere (proteins, nucleic acids
Geosphere (soil nitrates/ammonia)
Hydrosphere (dissolved nitrates)
Moves by: Nitrogen fixation, assimilation, denitrification
**Must be fixed by bacteria or lightning before plants and animals can use it.

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Essential Element: Phosphorus (P)
Critical for DNA, RNA, and ATP (energy molecule)
Where:
Geosphere (rocks, soil)
Biosphere (DNA, ATP, bones)
Hydrosphere (phosphates in water)
Moves by: Weathering, decomposition, plant uptake, sedimentation

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Essential Element: Sulfur (S)
Needed for proteins and some amino acids 
Where:
Geosphere (minerals, rocks, soil)
Atmosphere (SO₂ from volcanoes/fuels)
Biosphere (proteins in hair, skin, nails)
Hydrosphere (sulfates in water)
Moves by: Volcanic emissions, combustion, acid rain, decomposition
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Quick Check: Essential Elements
1. Rocks slowly break down, releasing nutrients that plants take up through their roots.
Which element is cycling? 
2. Water from the ocean evaporates, rises into the air, and falls again as rain.
Which element is cycling? 
3. A fish breathes in dissolved gas from water and releases a different gas as it respires.
Which element is cycling? 
4. A tree takes in gas from the air during photosynthesis and uses it to build glucose.
Which element is cycling? 
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Quick Check: Essential Elements (cont)
5. Lightning strikes and changes a gas in the atmosphere into a form plants can absorb from the soil.
Which element is cycling? 
6. A volcanic eruption releases gases into the air, which later combine with rain to form acid rain.
Which element is cycling? 
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Quick Check: Essential Elements (Answer)
1
Phosphorus (P)
2
Hydrogen (H)
3
Oxygen (O)
4
Carbon (C)
5
Nitrogen (N)
6
Sulfur (S)
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Overview Sphere Interaction
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Matter vs. Energy: Key Differences
Matter: Continuous Cycling
Matter is never created or destroyed within an ecosystem.
Atoms are reused: They are continuously recycled through biotic (living) and abiotic (non-living) components.
Closed-loop system: These elements cycle indefinitely, ensuring their constant availability for life processes.
Energy: One-Way Flow
Energy flows through an ecosystem in a single direction and is ultimately lost as heat.
Primary source of energy is the sun (Producers convert solar energy into chemical energy; photosynthesis).
The 10% Rule: Only about 10% of the energy is transferred from one trophic level to the next. 
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Explore 1: Molecule Madness Key
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Molecule Madness Debrief
1
Did you notice that the same spheres started with the same number of atoms, but the numbers at the end of the game were different? Why did that happen?
2
How would this mirror what happens with essential elements in our world?
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Investigative Phenomena
Organisms are only able to obtain about 10% of the energy available from the trophic level below it. What evidence supports this fact?
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Energy
The ability for a system to do work or produce heat; powers all life processes
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Trophic Level
An organism's position on a food chain
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Producers (Autotrophs)
Organisms that make their own food (autotrophs)
Examples: Plants, algae, phytoplankton
Capture sunlight → stores energy as glucose (photosynthesis).
Base of every food chain — supports all other levels.
~100% of the energy is here
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Primary Consumers (Herbivores)
Eat producers for energy 
Only ~10% of the producer’s energy passes to this level
Must eat more plants to survive
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Secondary Consumers (Carnivores/Omnivores)
Consumes primary consumers for energy
Only 10% of energy from herbivores passes on (~1% of original from producers)
Fewer organisms can survive at this level
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Tertiary Consumers (Carnivores)
Consumes secondary consumers for energy
10% of energy from secondary consumers passes on (~0.1% of original from producers)
Top carnivores in many food chains (not always the final predator)
Very few can be supported in an ecosystem
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Quaternary Consumers (Apex Predators)
Consumes tertiary consumers for energy
No natural predators
Only ~0.01% of the original energy
Small populations supported

Why do apex predators always have the smallest populations?
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Decomposers
Break down dead matter to recycle nutrients into soil and water
Examples: fungi, bacteria, earthworms, vultures, detritivores
Role in Ecosystems:
Recycle nutrients like carbon, nitrogen, and phosphorus back into soil and water
Release gases (like CO₂) back into the atmosphere
Ensure atoms are continuously available for producers
What would happen if decomposers were removed from ecosystems?
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Review: Energy Flow Through Food Chain
Energy starts with the Sun.
Producers (autotrophs) capture it.
Consumers (heterotrophs) transfers it.
Herbivores (eat plants only)
Carnivores (eat animals only)
Omnivores (eat plants & animals)
Decomposers recycle matter.
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Quick Check: Energy Flow in Food Chains
1. Which group of organisms captures energy from the sun?
A. Primary Consumers            C. Producers 
B. Secondary Consumers       D. Decomposers
2. In this food chain: 
Sun → Grass → Grasshopper → Frog → Snake → Hawk
Which organism is the tertiary consumer?
A. Grass                              C. Frog
B. Grasshopper                 D. Snake
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Explore 2: Food Chain Game (part 1) Key
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Food Chain Game (part 1) Debrief
1. How many primary consumers did not eat?
2. What did you notice about the number of organisms when you first started the food chain game?
3. Explain what happened to the organisms that were moved off to the side.
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Explore 2: Food Chain Game (part 2) 
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Food Chain Game (part 2) Debrief
1
What trends did you notice in the number of organisms at each succeeding trophic level?
2
What does this trend imply about the organisms at each trophic level in terms of nutritional requirements?
3
What difference was there between the number of organisms that survived in Part I and the number that survived in Part II?
4
Why is only 10% of the energy consumed by an organism available to be transferred to another trophic level?
5
We know that matter and energy cannot be created or destroyed, so what happens to available energy and matter when an organism dies?
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Trophic Level
An organism's position on a food chain
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Energy Pyramid
A representation of an ecological community showing the total amount of energy contained within each trophic level
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Pyramid of Biomass
A diagram to show the amount of mass present at each trophic level
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Food Web
A complex of interconnected food chains showing the trophic interactions in an ecosystem
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Explore 3: Hunger Games
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Explore 3: Hunger Games CER
Write a claim stating what impact the disappearance of organism VI will have on the ecosystem. Support your claim with evidence and scientific reasoning, and be sure to include mathematical representations.

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Explore 3: Hunger Games (Debrief)
1
How are the relative quantities of biomass related to the amount of available energy per trophic level?
2
Describe the difference between energy flow and the cycling of matter in an ecosystem?
3
How is the 10% rule helpful in determining the effects the disappearance of an organism will have on a food web?
4
How is the other 90% of energy consumed accounted for?
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Matter: Recycled

Atoms (C, H, O, N, P, S) get reused.
Moves in cycles (air, water, soil, living things).
Energy: One-Way Flow
Starts with the Sun.
Moves up the food chain.
Lost as heat at each step (10% Rule).
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Graphic Organizer
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Investigative Phenomena
Where does carbon come from to make glucose, the main energy component for organisms?
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Graphic Organizer
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The Carbon Cycle 
The continuous movement of carbon among the abiotic environment and living things
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Unit 2.2   Explore 1: The Carbon Cycle Game
Carbon is what makes life possible. It moves around the Earth through many different forms.
You will be a carbon atom, moving through the carbon cycle.
At the end, you will create a storyboard that chronicles your journey as a carbon atom.
Follow the instructions on your handout, and begin!
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Explore 1: The Carbon Cycle Game (Debrief)
What key processes did the carbon atom travel through?
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Disrupting the Carbon Cycle
When the rate of release exceeds the rate of absorption, carbon builds up in the atmosphere.
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Explore 3: Resources, Sustainability, & Biodiversity 
You will work in groups of 4 to model how resources, biodiversity, and human activity connect.
Please get into your assigned groups.
Begin reading Explore 3 with your partners

.
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Chemistry Review
Matter and energy connect through chemical reactions.
Let’s review the chemistry behind life’s molecules.
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Chemical Formula
Chemical formulas show which elements and how many atoms are in a compound
Symbols = elements (Ca = calcium, C = carbon, O = oxygen, H = hydrogen)
Subscript numbers = the number of atoms; no number = 1 atom
Example: Sulfuric Acid (H₂SO₄)
2 Hydrogens
1 Sulfur
4 Oxygen
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Chemical Formula Practice
Write down each element in the formula.
1.Record how many atoms of each element are present.
2.Double-check: Did you list all elements?
3.Example: H₂SO₄
H = 2
S = 1
O = 4
Quick Check: How many atoms total are in methanol (CH₃OH)?
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Chemical Equations (Inputs)
The starting substance(s), written on the left side of the chemical reaction arrow, which will be destroyed during a chemical change
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Chemical Equations (Outputs)
The ending substance(s), written on the right side of the chemical reaction arrow, that are created during a chemical change
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Balanced Equations
Law of Conservation of Matter: Atoms are rearranged, not created or destroyed.
Balanced equation = same number of each atom on both sides.
Photosynthesis and Respiration are opposites.
Example:
Photosynthesis: 6CO₂ + 6H₂O → C₆H₁₂O₆ + O₂
Respiration: C₆H₁₂O₆ + O₂ → 6CO₂ + 6H₂O
Quick Check: Count the atoms on each side — are they equal?
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Unit 2.1    Explore 1: Inputs and Outputs
Why are photosynthesis and cellular respiration called opposite reactions?
How is the energy different in both reactions?
What role does the environment play in both reactions?
What other ways could you model these reactions to better show the energy involved in these reactions?
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Do Now (15 minutes)
1. Complete Investigative Phenomena, Before Instruction section
2. Complete APK: Cellular Energy
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Photosynthesis (Anabolic Reaction)
a chemical process that autotrophs use to transform light energy into stored chemical energy in the form of glucose
Plants and some bacteria convert light energy → chemical energy (glucose)
Occurs in chloroplasts (contain chlorophyll)
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Photosynthesis: Light Dependent vs Light Independent
Light-Dependent: Uses light to make ATP & NADPH, releases O₂.
Light-Independent (Calvin Cycle): Uses ATP + CO₂ to build glucose.
What would happen if plants couldn't do the Calvin Cycle?
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Cellular Respiration (Catabolic Reaction)
the process by which cells convert chemical energy stored in various compounds, such as sugars, into useful energy for cellular processes; may be aerobic or anaerobic
All organisms break down glucose to release energy (ATP)
Occurs in mitochondria
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Cellular Respiration: Aerobic Respiration
Used when oxygen is present
Steps:
            1. Glycolysis
            2. Krebs Cycle
            3. Electron Transport Chain
Produces ~36 ATP per glucose
Slow ATP but most efficient (stamina)
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Cellular Respiration: Anaerobic Respiration
Used when there is a lack of oxygen
Produces only 2 ATP per glucose
Fast ATP but less efficient (speed)
Types of anaerobic reactions:
Lactic Acid Fermentation (animals)
Example: muscle fatigue
Alcoholic Fermentation (yeast)
Example: bread rising from yeast
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Quick Check: Cellular Respiration & Photosynthesis
1. What is the main purpose of photosynthesis?
To release energy stored in glucose
a.To use light energy to make glucose
b.To break down carbon dioxide into ATP
c.To recycle oxygen back into the atmosphere
d.
2. During cellular respiration, where is most of the energy from glucose released?
During glycolysis in the cytoplasm
a.During the Krebs Cycle in the mitochondria
b.During the Electron Transport Chain
c.During fermentation when oxygen is absent
d.
3. How are photosynthesis and cellular respiration connected? (Open-Ended)
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Explore 2: Elodea and Cellular Energy (Lab Report 2a)
Question: What color will test tubes filled with bromothymol blue solution turn under different conditions?
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Explore 3: Let it Burn!
Question: Why does it get harder to hold a wall squat over time?
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Explore 4: Anaerobic Investigation (Lab Report 2b)
Question: What conditions produce the most energy for organisms when oxygen is not available?
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Graphic Organizer
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Biomolecules (Overview)
Living things are built from four main macromolecules: carbohydrates, lipids, proteins, and nucleic acids.
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Carbohydrates
Made of C, H, O (1:2:1 ratio)
Primary source of energy
Examples: glucose, starch, cellulose
Types:
Monosaccharides (1 sugar)
Disaccharides (2 sugars)
Polysaccharides (many sugars)

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Lipid
Composed of C, H, O (fewer O than carbs)
Store energy long-term; form cell membranes.
Examples: fats, oils, steroids, cholesterol
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Proteins
.Contain C, H, O, N
Build tissues, enzymes, hormones, and transport molecules
Monomer: Amino acid
Examples: keratin, hemoglobin, insulin.

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Nucleic Acids

Contain C, H, O, N, P.
Store and transmit genetic information
Monomer: Nucleotide
Examples: DNA, RNA
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Review Carbon in Living Things
All biomolecules contain carbon.
Carbon’s versatility allows complex molecule formation.
Matter cycles through these molecules via food webs and decomposition.
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Explore 4: Building Biomolecules
1. Use molecular model kits or diagrams to build carbohydrates, lipids, proteins, and nucleic acids.
2. Record element composition and structure differences.
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Graphic Organizer
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Investigative Phenomena
Where does carbon come from to make glucose, the main energy component for organisms?
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Other Biogeochemical Cycles

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Hydrogen Cycle

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Oxygen Cycle
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Nitrogen Cycle

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Phosphorus Cycle

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Sulfur Cycle

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Review Game
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Homework
Complete in-class assignments that were not done.
Complete Assignment in STEMScopes
Carrying Capacity Math
Finish making vocabulary flashcards
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Homework
Complete Assignment in STEMScopes
Reading Science - Pollinators
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