A Multidisciplinary activity that involves the STEM disciplines

The focus is on the study of climatic factors and the causes leading to an increase in temperature. Age : 14-15 years STEM : math, science, biology, physics, English. Teachers: Mario Di Fonza, Sabrina Nappi, Rosanna Busiello, Josephine Iannone

Introduction

Song of crickets First, the students listen to the cricket song https://www.youtube.com/watch?v=UGOS4e99kj4 Students answer questions :

• Why do crickets chirp?
• Did you know that only male crickets chirp?

Pupils take a quiz on www.mentimeter.com

Possible answers: Crickets sing to…. 1. Call the female: male cricket’s challenge is to be loud enough to be heard 2. Courting ritual 3. Drive other males away. The song of crickets is the nocturnal soundtrack of our collective rural, suburban and even urban lives. Some other questions:

• Can a cricket help to study climate change? 
• How?
• Pupils take a quiz on www.mentimeter.com and a debate on the topic follows.

The species

Crickets are insects belonging to the orthoptera family, and as such they emit sounds called chirps.

The song of the cricket

The students listening with greater attention to the song of a cricket https://www.youtube.com/watch?v=UGOS4e99kj4. The most bizarre and interesting thing to observe is that this song is discontinuous and is related to the temperature. The temperature rises and you can hear the cries of crickets. The crickets “sing” rubbing their legs. The warmer the weather is, the faster they “sing”. The focus is on the study of climatic factors and the causes which are leading to an increase in temperatures as a function of the perceived chirps of crickets.

Thermometers of the poor

Crickets are considered the thermometers of the poor, an expression that comes from the observation that the chirping of these animals increases or decreases in relation to the temperature of the environment. Crickets are cold-blooded, which means they take on the temperature of their surroundings. The temperature rises and crickets chirp more easily. The temperature drops and the reaction rate of the crickets slows down, causing their chirping to decrease as well. The Engagement is curious and the students are invited to verify this discovery.

Investigation phase

In this paragraph, the Students are provided with data taken from a research carried out in 2007 in Boulder (Colorado, USA), and are asked if it is possible to find a relationship between the number of crickets’ chirps (f) and the location temperature (t).

The students analyze the data on the table and build a scatter chart by observing how the points are arranged through the use of google sheets, and discuss it in groups. The students, from reading the graph, create a mathematical model that relates the temperature to the song of the crickets: t = a ∙ f + b, number of crickets’ chirps (f) and the location temperature (t). The relation: t = a ∙ f + b gives the value of the correlation between the increase in temperature and the song of the crickets. Students write the equation of the regression line passing through the points in the graph and calculate the correlation coefficient.

Deepening on the blog

https://www.globe.gov/explore-science/scientists-blog/archived-posts/sciblog/index.html_p=45.html

Dolbear’ s Law

From the analysis of the data, students move on to analyze Dolbear’ s Law in physics. Amos Dolbear, was a 19th century American physicist, professor and inventor who studied various species of crickets to determine the relation between the number of chirps per minute and the ambient temperature. In 1897 Amos published an article “The cricket as a thermometer”, where the formula is reported (Dolbear’ s Law): T = 50 + ((N – 40) / 4) , where T is the temperature in Fahrenheit degrees and N is the number of chirps per minute. The students convert Fahrenheit to Kelvin. They convert them to Celsius as an exercise too. Dolbear’ s law, applied to the chirping of crickets, allows us to estimate temperatures between 55 and 100 degrees Fahrenheit. On summer evenings the crickets feel at their best.

Deepening with the sciences

The students reflect on the question: What happens in human beings if the internal temperature increases? The consequence is the link between physics and the sciences: the heart beats faster if the internal temperature increases. Pupils are asked, in pairs, to determine and share their body temperature by measuring the frequency of heart beats per minute, taking into account the relationship between heart activity and the internal body temperature reported: Resting adult

Resting adult	Fever inside the abdomen
with 70 beats per minute	37°C
with 80 beats per minute	37/38°C
with 90 beats per minute	38°C
with 100 beats per minute	38°C
with 110 beats per minute	39°C
with 120 beats per minute	40°C

Pupils discuss the table, observing how each degree Celsius of body temperature increase corresponds on average to 8 beats per minute increase in heart rate. In this way, the focus is on the study of climatic factors that increase temperatures. Exercises To get different results, the pupils tried to “warm up” by running or doing some physical exercise.

Deepening with the biology

The activity ends with the experimental part in biology which concerns the use of crickets to study the effect of temperature on the metabolism of cold-blooded organisms. Small insects have a trachea where diffusion occurs, carrying oxygen and removing the carbon dioxide necessary for cellular respiration. The students use the chemical reaction:   and the image: http://www.benesserelongevitasalute.it/2017/03/30/lenergia-e-la-vita/ Students are asked to: – find the correlation between the two images; – specify the reactants of this reaction, and the products; – describe what they observe; – specify what are the factors that can slow down or speed up a chemical reaction, and explain why? On a padlet (www.padlet.com), the students enter their thoughts.

CO₂ and temperature

The purpose of the activity is to determine how the temperature affects the respiratory rate of crickets by monitoring the production of carbon dioxide with a CO₂ gas sensor at different temperatures. The amount of CO₂ produced will determine the effect of temperature on the metabolism of crickets. The outline of the procedure for monitoring data collection of cold, intermediate and hot temperatures is provided to students divided into groups. The students enter data into tables and create graphs to read, they focus on the study of climatic factors and the causes which are leading to an increase in temperature.

The outline of the procedure

The CO₂ sensor must be connected to the data collection device. If your CO₂ gas sensor has a switch, set it to “Low” (0–10,000 ppm) placement. Change the data collection rate to 0.1 samples / second and the data collection duration to 600 seconds. Weigh 10 adult crickets, in a 600 mL beaker and record their data in Data and Observations.

Data and Observations

Temperature (c °)	Concentration (ppm / s)	Respiration Rate (ppm/s/g)
Assigned range	Current
5-10
10-15
15-20
20-25
30-35
40-45

Mass of crickets: 1.6g Student collect data as follows: 1st stage: The students, in the group, construct a graph and relate the measured CO₂ concentration and temperature. 2nd stage: The students prepare tubs with water at different temperatures, and The groups collect data on respiration at 5–10 ° C, 10–15 ° C and 15–20 ° C. 3rd stage: The students prepare a water bath for the desired temperature. This ensures that the crickets will remain at a constant and controlled temperature. To prepare the water bath, get fresh water and ice. 4th stage: The students mix cold water and ice in a 1 liter beaker. The beaker is filled with approximately 600–700 ml of water. The thermometer is placed in the water. The breathing chamber is in the water. 5th stage: The students use a pipette to remove or add hot or cold water as needed. 6th stage: Record the water bath temperature in Data and Observations.

Conclusions

Grilli che c(a)ontano! is focused on the study of climatic factors and the causes that lead to the increase in temperatures, aims to sensitize pupils to the issue of climate change consequences of environmental conditions. Thanks to the use of the IBSE methodology, the pupils observed how mathematical relationships are concretely found in nature, or how life, as we know it, depends on physical and biological factors. The purpose of this activity is to provide evidence on how the effects of global warming can cause negative impacts on ecosystems and on the metabolic activities of individuals. Furthermore, the students reflect on the important theme of energy emitted by the sun that is captured from the planet Earth and used by individuals to produce energy and work (metabolism).