DEPARTMENT OF BIOLOGY

FACULTY OF SCIENCE AND MATHEMATICS

UNIVERSITI PENDIDIKAN SULTAN IDRIS

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SBI 3013

INFORMATION AND COMMUNICATION TECHNOLOGY IN BIOLOGY

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STELLA: SIMULATION IN TEACHING AND LEARNING

NAME MATRIC NO.AISYAH SAHIRA BINTI ABDUL RAHIM D20141066916AIN SOFEA SYAHIRAH BINTI MAHADI D20141066891

LECTURER’S NAME: ENCIK AZMI BIN IBRAHIM

Introduction

Information and Communication Technology (ICT) brings a big impact to people

nowadays especially when it related to scientist and researches. Many experiments that have

been done succeeded with the aid of the technological devices. These devices gives

advantages as it helps in reducing time in conducting experiment and we are able to compare

the theoretical result with the results that we obtained efficiently.

One of the technology that been used is a STELLA.

What is a STELLA?

STELLA is a software that allows modelling and simulation. It is a type of flexible

computer modelling package that provides an interface which allows users to develop or

construct a models of experiment. In its most basic form, modelling in STELLA proceeds in

three steps which are constructing a qualitative model, parameterizing it, and exploring the

model's dynamics.

We use STELLA to simulate a system over time. This software reduces time

efficiency as it can be done at any time with the usage of internet. STELLA also allows us to

jump the gap between theory and the real world. We can use the simulation to identify

whether the theory is acceptable with the result that we obtained or not. It enables students to

creatively change systems and teach students to look for relationships. We can clearly

communicate system inputs and outputs and demonstrate outcomes.

There are four building blocks in the modelling process which comprises of stocks,

flows, connectors and converters. Stocks is the very basic thing in building blocks as it is

used to represent anything that accumulated such as population, biomass, nutrients and water.

Those are a type of tangible, physical and countable accumulations. These stocks can also be

used to represent the degree of non-physical accumulations. Besides that, flows are used to

represent activities which are the input and output. Input are the thing that we key in while

the output are the result of the simulation that we constructed. Examples of flows are the

births, migration, nutrient or the transport of biomass. All of the activities could change the

magnitude of a stocks in the system.

A connector is used to transmit the information in order to regulate the flows

mentioned earlier. These connectors are able to connect into flows but never connects into the

stocks. This is due to flows affect the magnitude of stocks. However, the connectors could

affect both input and also output. As for the converters, it contains the equation which

generates an output value during each time interval of a simulation. These converters takes

up the information and transform it for the use by any other variable in the model. They came

in handy in storing constant values.

This are the example of the model tools composed of stock, flow, connector and a converter.

Below are the example of a simulation control panel:

What is simulation in teaching and learning?

A simulation is a form of experiential learning. It is a strategy that fits well with the

principles of Student-Centred and constructivist learning and teaching. Simulation is a

technique of study or learning by mimicking it to a computer application. It is a process of

using a model tools by manipulating variables that cannot be changed in real life. Users can

change any variable that they want in order to know the results in a shorter period. A

computer simulations allows students to learn visually about problems that they do not

simply understand in real life.

How simulation enhances student learning?

Simulation is a type of visual learning which aids in enhancing students problem

solving skills. It helps to approach and increase student comprehension and allows students to

explore nature of things using scientific simulations. The creative aspect of the simulation

makes it seems more fun to handle. Thus, this makes the students feels the enjoyment of their

educational experience. Moreover, the pressure to solve a problem by changing the variables

can motivate students in learning new things. This simulation process enhances their

knowledge of such abstract theories and concepts.

Simple Nitrogen Cycle

The experiment that we had chosen by using this Stella sample models is Nitrogen

Cycle. But first of all,lets have clear view on what Nitrogen cycle is all about. Nitrogen cycle

is initated with the atmospheric nitrogen .It is occupied 78% of air. Nitrogen are occupied in

amino acid,nucleic acid and also ATP. They have a few step in this cycles which is nitrogen

fixation,nitrification and denitrification. The cycle involved several factors such as

atmosphere,hydrosphere and lithosphere. The first step in order to undergoes Nitrogen Cycle

is Nitrogen Fixation. This step occur because of neither plants and animals can obtain

nitrogen directly from the atmosphere. They have to be change the form first before transfer it

to the animals and plants. Nitrogen must be combined with the hydrogen to form

ammonium(NH4) ions or with Oxygen to form Nitrate ions(NO3).Plant cannot use nitrogen

in our atmosphere without assistance of nitrogen-fixation bacteria. The bacteria that

responsible in nitrogen fixation process is symbiotic bacteria which are associate with the

legume’s root nodules. These bacteria are known as nitrogen-fixation bacteria. The popular

bacteria that responsible for the nitrogen fixation is Rhizobium. Nitrogen fixation is an

anaerobic process. This process start with nitrogen (N2) that had been reduced to ammonia

( NH3) which can be used to make other biological compounds. The plants don not use the

ammonia directly but it ia a product of a waste. The nitrogen is converted to ammonia by the

enzyme of dinitrogenase. The symbiosis between legumes and the nitrogen-fixing bacteria

rhizobia occurs within nodules,mainly on the root. But a few case occur on the stem. The

bacteria reduce atmospheric nitrogen to ammonia. This ammonia is transferred from the

bacteria to the plant. Plant used this nutritional nitrogen for synthesis of

proteins,enzymes,nucleic acids,chlorophyll and others. Some convert the nitrogen into

ammonia (NH3) with the help from nitrogen –fixing bacteria in a root nodules of legumes

then convert to ammonium (NH4) with the help from ‘nitrogen-fixing soil bacteria. Other

than that,with help from the decomposer such as bacteria and fungi the nitrogen can directly

convert to ammonium ion. This process known as ammonification. It is begin when plants

and animal dies and it is decompose or when animals excrete waste. The nitrogen-fixing

bacteria in soil or decomposer bacteria convert nitogen into ammonium.

Nitrification occurs when nitrifying bacteria convert ammonium to nitrate.Certain

species of these bacteria make nitrite (NO2-) from ammonium and others make nitrate(NO3-)

from nitrite.The last step is denitrification.This process occurs when microorganisms convert

nitrate (NO3-) into the gases nitric oxide(NO),Nitrous oxide(N2O) and nitrogen(N2).This

bacteria that responsible for the denitrification process live in wet soil .It involve in an

anaerobic condition which is use nitrate instead of oxygen.

By using the stella, we need to conduct the experiment and get the result by changing

the parameters. From the given parameters, they have 4 different condition that can change

which is humification fraction, mineralization fraction, nitrogen per unit biomass, and

fraction productivity. After we had discussed about this experiment,me and my partner had

decided to change one variable which is humification fraction in order to identify the effect

on the cycle if we change the variable either it will effect the result or it remain the same.

The first step is to let the variable of humification fraction at the rest which is does not

change the variable. The result is constant or remain at the same stage. Only the humification

fraction that we manage to change. The other factors remain the same.

After that, we changed the parameter from the 0.2500 into 0.5000

From the graph above ,we can see that the graph start to change if we change the

parameters.When the value of humification fraction increase to 0.5000 as we can see that the

graph of nitrogen in organic matter represent the value.The value of the nitrogen in organic

matter is the same with the value of nitrogem per unit biomass.When the parameter change

into 0.8000 the value of nitrogen in organic matter is lower than the value of nitrogen per unit

biomass and we increase again the parameter from 0.8000 to 1.0000.The value of nitrogen in

organic matter keep decreasing.But for the value of humification fraction,it remain constant

at the higher level if we increasing the value of parameter for the humification fraction.They

do not increasing again but remain at the same value.Thus humification fraction will affect

the graph if or in the production of compost.we increase the value of the parameter. The

process of humification can occur naturally in soil.Humification or can be known as

humus.Humus is a organic matter that has been used or transformed.Humus significantly

influences the bulk density of soil and contributes to moisture and nutrient

retention.Increasing the value of humufication fraction will increase the nitrogen in humus

and the value of the nitrogen in organic matter is decrease because the value of nitrogen

transform into humus increase which is many nitrogen has been used up and only small

amount of nitrogen in organic matter left.

Advantages of using simulation in teaching and learning

Advantages of using simulation in teaching and learning process as it help users

especially student to design their own experiment by using this application with the help of

practical tutorial.It is easy for them design the experiment by follow the tutorial given or to

guide them before conduct the experiments. Other than that,students are able to study the

behavior of the system without building it.If the experiments required them to built the

rocket or other object,they do not worry about that because by using this application all of

the information and model are provided in this application or we can search through the

google.Student can see clearly the accurate result showed by the simulation.The result will be

appeared mostly in the form of graph.From that,student can see the result clearly and make

the comparison if the changes in the value or graph occurred.The result also appeared quickly

so they have a lot of time to think about the result and make it discussion based on

that.Next,able to study and inverstigate the natural condition such as nitrogen cycle by using

the simulation model.Student can easily conduct the experiment that relate to the natural such

as nitrogen cycle,photosynthesis or respiration. We cannot see the process infront of us or by

using naked eyes but actually the process occurs everytime.By using this application,student

can design the experiment that relate to it and study about it.This stella also can be used to

investigate the situation that would be dangerous in real life.The last advantage is stimulator

can be used an effective ways for teaching or demonstrating concepts to students.This

stimulator help the teacher to not to do a real experiments in order to study the concept.The

teacher only need this stimulator and create the experiments n order to teach the concept and

also the student can gain many skills by using this stimulator such as thinking

skills,prediction skills in order to predict the result that will come out and others.

Disadvantages simulation of teaching and learning

The disadvantages by using the stimulator is it is required internet connection in order

to design the experiments.It is difficult because sometimes some place does not have internet

connection or limited internet connection,this will disturb when the user want to design the

experiments.Next,it is difficult to interpret the simulation results.Some of the student will

carry out the complex experiment by using this simulation,the result that will come out also

not easy to interpret.They need high thinking skills in order to interpret the resut in the form

of graph or data.Other than that, simulation modelling and analysis can be time consuming

and expensive.Some of the experiment that will carry out it need this simulation

application.Some of the application need to buy that will required high cost and also some of

the application need to be downloaded.It takes a time in order to downloaded.Finally, student

have a poor understanding of how physical systems work.This is very important because

especially for the engineering student,it required more practical.If they design the experiment

by using this stell,They only need to sit infront the laptop and create the experiments.This

will cause them to loss their skills.

Conclusion

To conclude, this STELLA software gives many advantages rather than disadvantages. With

just a click and entering the input, we are able to know the result for the simulation

experiment. Not only the result but also the graph and the table too. This gives many good

impacts especially for students who did not have much time to conduct an experiment and

some of student may have bad result for the experiment that they conducted. But the thing

that lack in this software is that, students will lack of practical in handling the experimental

procedures and tools. This reduces their efficiency in conducting experiment.

References

Retrieved from http://www1.union.edu/rices/STELLA/stella_intro.html

Retrieved from http://www.iseesystems.com/softwares/Education/StellaSoftware.aspx

Retrieved from http://access.ncsa.illinois.edu/Archive/backissues/92.4/92.4Stella.html