Sea to Shore Lab: Thermoregulation

Why are animals shaped differently in cooler climates than in warmer ones?

Overview

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

Materials (Per lab group)

12.5 oz modeling clay
Heating pads or lamps
Ice bath
Vernier (or similar) temperature probes
Vernier (or similar) interface

Shaw, T.J. & French, D.P. (2018). Authentic Research in Introductory Biology, 2018 ed. Fountainhead, Fort Worth.

Assessments

PreLab

Quiz

Keys and additional instructor-only notes (you will be asked to sign into a Google account and request access to view instructor materials)

Lab report rubric

July 20, 2018December 18, 2018

Sea to Shore Lab: Diffusion

Why is diffusion through a membrane sometimes faster?

Overview

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

Materials

Per lab group

Dialysis tubing (3 different diameters) with clamps
Hot plates
Ice bath
Vernier (or similar) temperature probes
Vernier (or similar) interface
Vernier (or similar) ion probes – or Potassium Ion-Selective Electrode or Salinity Sensor
Salt solution
Glucose solution
Starch solution
DI water
IKI solution
Beakers

Shaw, T.J. & French, D.P. (2018). Authentic Research in Introductory Biology, 2018 ed. Fountainhead, Fort Worth.

Assessments

PreLab Activity

Quiz

Keys and additional instructor-only notes (you will be asked to sign into a Google account and request access to view instructor materials)

Lab report rubric

September 4, 2018October 30, 2018

Thermoregulation and ratio of surface area-to-volume

Outcomes: 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 2Identify organisms as endotherms, ectotherms, poikilotherms/heterotherms, and homeotherms based on: A) physical characteristics B) behavior C) metabolic changes D) membership in taxonomic groups (birds, mammals, etc.) E) changes in body temperature measurements, Thermoregulation 3Predict the effect of varying environmental temperatures on an organism's behavioral or metabolic responses including: A) enzyme activity B) locomotion C) body temperature, Thermoregulation 4Interpret data/graphs as they relate to the effect of varying environmental temperatures on an organism's behavioral or metabolic responses including: enzyme activity
locomotion
body temperature
, Thermoregulation 5Design or critique simple experiments to test the effect of varying environmental temperatures on an organism's behavioral or metabolic responses including: A) enzyme activity B) locomotion C) body temperature, 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, Thermoregulation 7Explain why organisms thermoregulate., Thermoregulation 8Explain mechanisms of heat generation at the cellular level.

The purpose of this activity is to illustrate the important role of SA/V in maintaining gradients. Students compare how life has evolved in extreme biomes namely by comparing images of the ear size of desert and tundra dwelling animals and connecting this structure with an animal’s ability to maintain homeostasis (i.e. temperature gradients and thermoregulation).

Engage students by showing a photo of a desert biome and a tundra biome (see below). It is important that some plants be visible in each photo (not photos of sand dunes or snowpack) to illustrate that life can exist here. Ask students to make observations and compare and contrast each biome with their neighbors/teams. Ask students “What do you think might be an obstacle to life in these biomes?” and they usually respond with “temperature extremes and lack of liquid water.” Tell students, “Let’s look at the living things that have evolved to live in these extreme biomes.”

Prepare presentation slides with images of similar tundra and desert animals side by side for comparison by students (see below). Select images that prominently display the ears and legs of each animal so that students can eventually recognize the role of the ratio of surface area-to-volume in thermoregulation. Ask students to compare and contrast the body shapes of the following animals: Arctic Hare v. Jackrabbit, Lemming v. Kangaroo rat, Arctic fox v. Kit fox. It may help to show these images repeatedly as students discuss how the body shapes differ. Students will initially describe the animals as “chunky,” “skinny,” “fluffy,” etc. You may want to point out to students that it is difficult to measure how “fluffy” an animal is, so they should try describe the animals using surface area and volume.

Students soon realize that these two measurements are linked; as volume increases so does surface area. Although some students will start referring to these measurements as a ratio, many students will need prompting to make this connection.

Visual aids for thermoregulation and ratio of surface area to-volume from ibis_curriculum

Ask students to work in groups to research and find organisms to complete this table:

	Poikilotherm	Homeotherm
Endotherm
Ectotherm

(Thermoregulation 1Apply the terms endotherm, ectotherm, poikilotherm/heterotherm, and homeotherm to organisms, Thermoregulation 2Identify organisms as endotherms, ectotherms, poikilotherms/heterotherms, and homeotherms based on: A) physical characteristics B) behavior C) metabolic changes D) membership in taxonomic groups (birds, mammals, etc.) E) changes in body temperature measurements)

After students work with the concepts of gradients and membrane transport, you may want to engage them this following case study:
- Gradients and Thermoregulation: Left out in the cold! – While backpacking in the Canadian Rockies, Joel loses his way and finds that his experience hiking and camping in his home state of Florida hasn’t prepared him for springtime weather conditions in the mountains. This case study allows students to review and integrate physiological responses to cold exposure. (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))