In this scenario, students are asked to consider what constitutes life, its origins, and the evidence needed to demonstrate that something is alive.
| Time (hrs) | Corn CO2 (ppm) |
|---|---|
| 0 | 442.5 |
| 1 | 813.5 |
| 2 | 993 |
| 3 | 1200 |
| 4 | 1390.5 |
| 5 | 1572.5 |
| 6 | 1777 |
| 7 | 1945 |
| 8 | 2060.5 |
| 9 | 2205.5 |
| 10 | 2353.5 |
| 11 | 2469 |
| 12 | 2543.5 |
| 13 | 2643.5 |
| 14 | 2751 |
| 15 | 3008 |
| 16 | 3173.5 |
| 17 | 3327.5 |
| 18 | 3449 |
| 19 | 3611 |
| 20 | 3761 |
| 21 | 3873 |
| 22 | 4139.5 |
| 23 | 4255 |
| 24 | 4404.5 |
What does it mean to be alive? How did the first cells form, and what traits did these earliest cells possess? How do living things function in varied environments? In this scenario, students are asked to consider what constitutes life, its origins, and the evidence needed to demonstrate that something is alive. Students are introduced to the molecules common to all living things, and the structure and function of cells. Students make observations of animal body shape, and apply knowledge of gradients and chemical activity to develop a working hypothesis about the ratio of surface area-to-volume, and its impact on homeostasis, metabolism and ultimately, survival. Instructors could use examples from extreme environments or journeys to other planets as contexts for this investigation and guide student inquiry.
Life Learning OutcomesChemistry Learning Outcomes
Cell Learning Outcomes
Ratio of surface area-to-volume (SA/V) Learning Outcomes
Gradients Learning Outcomes
Membrane Transport Learning Outcomes
Thermoregulation Learning Outcomes
Osmoregulation Learning Outcomes
Students are introduced to the characteristics of life, including organization, biochemistry, and homeostasis.
There are several possible options for how to present the topics.
The purpose of this lab is to get students relating surface area/volume ratio to the way in which an animal thermoregulates (by using modeling clay). At the conclusion of this investigation, students should also be writing a better lab report, able to produce a XY scatter plot with a trendline, and perform a simple statistical test. They will be using modeling clay to simulate body shapes, and temp probes to monitor any changes. They may craft any shape they like, provided that 1. They can calculate the SA/V ratio of the shape, and 2. They can accurately record its temp with the probe (shapes like a long cylinder or flattened box do not work well as there is little clay surrounding the temp probe).
Outcomes: Inquiry 4Construct hypotheses to explain biological phenomena: A) Propose hypotheses that are appropriate to the given scenario or question. B) Evaluate several hypotheses to select the one which best explains observations, or is best supported by data. C) Predict what would be most likely to occur under given experimental conditions in a test of..., Inquiry 5Design experiments to test biological hypotheses: A) Identify the dependent and independent variables, and control and experimental treatments in any experiment. B) Identify situations in which no “control treatment” is appropriate, and design an experiment where subjects are tested more than once or the experimental treatment levels take a wide range of..., Inquiry 6Create graphs from a data set. A) Decide what type of graph is the most appropriate type to display a data set. B) Decide to which axis each variable should be assigned in order to represent a specific hypothesis properly. See materials aligned with Inquiry 6, Inquiry 7Use experimental results to support or refute a hypothesis: A) Interpret graphs and/or raw data with respect to a hypothesis B) Distinguish correlation from causation, and correctly attribute phenomena to biological mechanisms. C) Demonstrate how to distinguish observations/data resulting from a specific cause from those caused by random chance. D) Explain why experimental evidence..., Inquiry 8Interpret and communicate scientific ideas effectively: A) Use the conventions of scientific writing, including images and graphs, e.g. in laboratory reports. B) Interpret and paraphrase information from valid sources, such as the textbook and the primary literature. See materials aligned with Inquiry 8; SA/V 1Calculate the ratio of surface area-to-volume of an object, and explain why the ratio decreases as objects get larger and increases as objects get smaller.; Gradients 1Explain what a gradient is and the role of gradients in: A) Homeostasis B) Thermoregulation C) Osmoregulation D) Chemical reactions associated with metabolism, Gradients 2Identify whether a chemical or energy gradient exists in new situations, Gradients 3Indicate the direction of energy or material movement under different conditions such as: A) Chemical concentrations B) Temperature C) Permeability of membranes, Gradients 4Indicate the relative rate of energy or material movement under different conditions including: A) chemical concentrations B) temperature C) permeability of membranes D) varied shape (surface-to-volume ratio); Thermoregulation 1Apply the terms endotherm, ectotherm, poikilotherm/heterotherm, and homeotherm to organisms, Thermoregulation 6Explain how various temperature regulation methods serve to heat or cool an organism including: A) avoidance B) altering metabolic rate C) behaviorally adjusting posture, ratio of surface area-to-volume, and location D) explain how ratio of surface area-to-volume is involved in heat retention or loss
Shaw, T.J. & French, D.P. (2018). Authentic Research in Introductory Biology, 2018 ed. Fountainhead, Fort Worth.
Keys and additional instructor-only notes (you will be asked to sign into a Google account and request access to view instructor materials)
This lab should help students understand the extremely important role of gradients. Focus on the idea that gradients occur whenever there is a concentration difference from high to low. Gradients do not just occur in liquids there can be gradients in temperature, Na and K ions, smoke, perfume, people, etc.
Students should be familiar with the terms solute, solvent, hyper-and hypotonic. Osmosis refers to the movement of water and dialysis typically to the movement of solute. Students may or may not comprehend the concept of ion, but you can simply leave it as a charged atom or particle or molecule. Unfortunately, if they don’t have some clue about ions or at least that NaCl becomes Na+ and Cl- when dissolved, the understanding what conductivity tells them is difficult. The pre-lab explains it, but be prepared.
Outcomes: Inquiry 4Construct hypotheses to explain biological phenomena: A) Propose hypotheses that are appropriate to the given scenario or question. B) Evaluate several hypotheses to select the one which best explains observations, or is best supported by data. C) Predict what would be most likely to occur under given experimental conditions in a test of..., Inquiry 5Design experiments to test biological hypotheses: A) Identify the dependent and independent variables, and control and experimental treatments in any experiment. B) Identify situations in which no “control treatment” is appropriate, and design an experiment where subjects are tested more than once or the experimental treatment levels take a wide range of..., Inquiry 6Create graphs from a data set. A) Decide what type of graph is the most appropriate type to display a data set. B) Decide to which axis each variable should be assigned in order to represent a specific hypothesis properly. See materials aligned with Inquiry 6, Inquiry 7Use experimental results to support or refute a hypothesis: A) Interpret graphs and/or raw data with respect to a hypothesis B) Distinguish correlation from causation, and correctly attribute phenomena to biological mechanisms. C) Demonstrate how to distinguish observations/data resulting from a specific cause from those caused by random chance. D) Explain why experimental evidence..., Inquiry 8Interpret and communicate scientific ideas effectively: A) Use the conventions of scientific writing, including images and graphs, e.g. in laboratory reports. B) Interpret and paraphrase information from valid sources, such as the textbook and the primary literature. See materials aligned with Inquiry 8; SA/V 1Calculate the ratio of surface area-to-volume of an object, and explain why the ratio decreases as objects get larger and increases as objects get smaller., SA/V 2Explain how the ratio of surface area-to-volume plays a role in regulating: A) Rates of diffusion and osmosis B) Gas exchange C) Body temperature; Gradients 1Explain what a gradient is and the role of gradients in: A) Homeostasis B) Thermoregulation C) Osmoregulation D) Chemical reactions associated with metabolism, Gradients 2Identify whether a chemical or energy gradient exists in new situations, Gradients 3Indicate the direction of energy or material movement under different conditions such as: A) Chemical concentrations B) Temperature C) Permeability of membranes, Gradients 4Indicate the relative rate of energy or material movement under different conditions including: A) chemical concentrations B) temperature C) permeability of membranes D) varied shape (surface-to-volume ratio); Membrane Transport 2Explain how processes of transport work including: A) Diffusion i) Passive ii) Facilitated B) Osmosis i) Passive ii) Facilitated C) Active transport, Membrane Transport 3Define the following terms, and explain how they relate to the movement of materials across a membrane: A) Isotonic B) Hypotonic C) Hypertonic, Membrane Transport 5Predict how the following conditions affect membrane transport: A) gradient conditions B) temperature C) ATP availability D) changes in permeability E) molecule size, charge, or polarity
Per lab group
Shaw, T.J. & French, D.P. (2018). Authentic Research in Introductory Biology, 2018 ed. Fountainhead, Fort Worth.
Keys and additional instructor-only notes (you will be asked to sign into a Google account and request access to view instructor materials)
Objectives: Life 1List and explain the characteristics of life., Life 2Use these characteristics of life to distinguish between living and nonliving things., Life 3Define homeostasis, and describe its importance to maintaining life.; Inquiry 5Design experiments to test biological hypotheses: A) Identify the dependent and independent variables, and control and experimental treatments in any experiment. B) Identify situations in which no “control treatment” is appropriate, and design an experiment where subjects are tested more than once or the experimental treatment levels take a wide range of..., Inquiry 6Create graphs from a data set. A) Decide what type of graph is the most appropriate type to display a data set. B) Decide to which axis each variable should be assigned in order to represent a specific hypothesis properly. See materials aligned with Inquiry 6, Inquiry 7Use experimental results to support or refute a hypothesis: A) Interpret graphs and/or raw data with respect to a hypothesis B) Distinguish correlation from causation, and correctly attribute phenomena to biological mechanisms. C) Demonstrate how to distinguish observations/data resulting from a specific cause from those caused by random chance. D) Explain why experimental evidence...
Objective: Life 4Compare and contrast the biological/medical, legal, and ethical definitions of life and death, and discuss the importance of defining life and death.
Objectives: Chemistry 1Explain why water is essential to life and how the characteristics of polarity and hydrogen bonding are important for this role., Chemistry 2Identify the four macromolecules, and define their roles/functions in a cell., Chemistry 3Explain the difference between ionic, covalent, and hydrogen bonds, and identify the relative strength of each type of bond., Chemistry 4Predict which type of bond would be formed between two (or more) atoms., Chemistry 5Describe the relationship between monomers and polymers, and give examples for each type of biological macromolecule listed below: a) Proteins b) Nucleic acids (RNA, DNA) c) Carbohydrates
Clicker questions could be used to collect student answers. Note that students often have difficulty with matching when there is not one-to-one correspondence (e.g., more than one macromolecule has more than one function). (Chemistry 2Identify the four macromolecules, and define their roles/functions in a cell.)
Outcomes: Cell 1, Cell 2, Cell 3Predict the organismal group to which an unknown cell might belong from a description of its components., Cell 4Predict the possible functions of an unknown cell depending on its components., Cell 5Predict the abundance of particular organelles depending on a cell's functions.
Outcomes: Gradients 2Identify whether a chemical or energy gradient exists in new situations, Gradients 3Indicate the direction of energy or material movement under different conditions such as: A) Chemical concentrations B) Temperature C) Permeability of membranes, Gradients 4Indicate the relative rate of energy or material movement under different conditions including: A) chemical concentrations B) temperature C) permeability of membranes D) varied shape (surface-to-volume ratio); Membrane Transport 2Explain how processes of transport work including: A) Diffusion i) Passive ii) Facilitated B) Osmosis i) Passive ii) Facilitated C) Active transport, Membrane Transport 3Define the following terms, and explain how they relate to the movement of materials across a membrane: A) Isotonic B) Hypotonic C) Hypertonic, Membrane Transport 4Explain how larger objects/molecules cross membranes by exocytosis, endocytosis, and phagocytosis, and predict when each of these transport mechanisms is used., Membrane Transport 5Predict how the following conditions affect membrane transport: A) gradient conditions B) temperature C) ATP availability D) changes in permeability E) molecule size, charge, or polarity; Thermoregulation 7Explain why organisms thermoregulate.
Prerequisite objective: Membrane Transport 1Identify the components of cell membranes, and explain how the arrangement of components makes the membrane semi-permeable.
| Diffusion | Facilitated diffusion | Active transport | |
| Description | Passive movement of… | Passive movement of… | Active movement of… |
| Are proteins involved? (yes/no) | No |
Follow up with clicker questions on how gradients relate to membrane transport. (Gradients 3Indicate the direction of energy or material movement under different conditions such as: A) Chemical concentrations B) Temperature C) Permeability of membranes, Gradients 4Indicate the relative rate of energy or material movement under different conditions including: A) chemical concentrations B) temperature C) permeability of membranes D) varied shape (surface-to-volume ratio), Membrane Transport 3Define the following terms, and explain how they relate to the movement of materials across a membrane: A) Isotonic B) Hypotonic C) Hypertonic, Membrane Transport 5Predict how the following conditions affect membrane transport: A) gradient conditions B) temperature C) ATP availability D) changes in permeability E) molecule size, charge, or polarity)
