Bacteria (mixt lesson – experimental and applicative)

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Bacteria (mixt lesson – experimental and applicative)

Biology

Lesson plan #2

ABOUT THE LESSON
Topic	Bacteria (mixt lesson – experimental and applicative)
Duration	2 hours (2 x 45 min)
Assumed prior knowledge	The cell – basic structural, functional and genetic unit of an organism. Morphological characteristics of bacteria
Goal(s) of the lesson	Formation of practical and intellectual skills in order to understand the structure – function correlation, specific to bacteria
The big idea behind the topic	Microorganisms are diversified in their nutritional requirements. Different species of microorganisms require different culture media to successfully grow and reproduce. Integrated application of knowledge in everyday life relating to the structures and organisms with potential pathogens as well as to the action of mutagenic factors. Designing of protection activities and environmental conservation.
Results of the lesson	Students will form and develop: the ability to interpret structural characteristics of cells and correlate them with their functional peculiarities; the capacity for interdisciplinary transfer, in order to solve problem situations; the ability to correlate information and state conclusions.
Competencies	General competences: Receiving information about the living world Exploring biological systems Using and building models and algorithms to demonstrate principles of the living world Oral and written communication using correctly the scientific terminology specific to biology Transfer and integration of knowledge and working methods specific to biology in new contexts
	Specific competences: 1.2. Classification of biological individuals based on general characteristics 1.3. Identifying the microscopic structures of bacteria in order to characterize them 2.2. Processing the results obtained from investigations and formulating conclusions 3.2. Application of problem identification and problem-solving algorithms 4.1. Correct use of terminology specific to biology 5.1. Applying the acquired knowledge in everyday life.
Methods	Teaching methods: Heuristic / learning consolidation conversation; Explanation; Demonstration; Problematization; Brainstorming; Analysis and synthesis; Systematization, algorithmization, modelling; Direct discovery; Laboratory experiment. Forms of activity: Frontal – for communicating / updating knowledge; Individually / in teams – for experimental activities.
Relevance to the curriculum	Awareness that environmental and climate change and pollution strongly influence the lives of human beings. Possible and / or useful connections to Chemistry part, Physics, Sensors Sampling Communications, and Filtering Modules.
Stakeholder involvement	Independent school activity (general situation). Possible assistance or/and support and connected activities during Biology disciplines classes (in own school or at partner schools) or thematic activities in local Scientific Centres (if available).

EQUIPMENT AND MATERIALS NEEDED

For 1 team of 5 students (if necessary for solving a problem situations)

Item	Quantity	Remarks
Computers (in school labs), with Internet access	1/class (1/student, if available)	Other available IT equipment can be used (laptops, tablets, mobile phones), with Internet access The lesson is mixt (experimental, and applicative), so it should be organized in a biology laboratory, if available, or in a classroom offering the necessary facilities.
Video projector	1/class
Projector screen	1/class
Audio system	1/class
Microscope	1/team
Lamella (blades, slides)	2-3/team
Pipettes	2-3/team
Non-pathogenic bacterial culture	Quantities will be decided accordingly
Basic fuchsin solution
Methyl blue solution

This is a recommended list:

Observations

In each class / lab, 1-2 blackboards or whiteboards (magnetic and/or interactive), with chalk or markers to write on, will be available.
Teachers will offer students necessary informative and practical support (school textbook, botanical atlases, worksheets, electronic presentations, online thematic images, videos, and tutorials).

STEP-BY-STEP ACTIVITIES

Step 1 (5 min)

Organizational moment (checking presence, capturing attention, preparing didactic materials, verifying and correcting students' homework, etc.).

Step 2 (10 min)

Updating the previous knowledge necessary for teaching.
Students are asked to fill in a table, to compare prokaryote and eukaryote cells (similarities and differences):

Comparison	Prokaryote	Eukaryote
Similarities	1. …
	2. …
Differences	1. …	1. …
	2. …	2. …

Step 3 (25 min + 5 min)

Making and observing the microscopic preparation
Stages of the experiment:

Teacher processes a biological preparation (, before the actual experiment (eventually, with the help of 1-2 dedicated students from the class or from an advanced class)
Students realise the microscopic preparation, according to the worksheet indications
Students make observations of the microscopic preparation, using objectives of different sizes
Students fill in the observation sheet
Students process the obtained data, in order to fill the general table (on the board and/or on their notebooks)

Characteristics of the bacterial cell (Bacillus subtilis)	Presence/Absence
Cell membrane	………………
Cytoplasm	………………
Nucleus	……………….
Locomotive formations	……………….
Cell shape	……………….
Organisation mode	……………….

Observation

Stage 0: Teacher could record a video or prepare a set of pictures, to detail the process (of 4-6 days – see the worksheet), in order to present it to the class. It would be interesting, for students, to see the phases of the process and understand the way the biological preparation was made (working mode, safety working rules, conditions to be ensured, necessary time, etc.). The video presentation will require supplementary 5 min).

Step 4 (30 min)

Establishing experiment conclusions.

Each team use their tables, filled in at the end of the experiment, to realise a general concluding table, on the black/white board, or on a flipchart sheet (table to be included in their own notes).

Sample	P1	P 2	P 3	P4	P5	P6
Estimated value of the presence of bacteria
Reduced (+)
Raised (++)
Very high (+++)

Step 5 (14 min)

Impression and consolidation of the new knowledge.

Based on the results obtained, students establish the correlation between the presence of bacteria in the analysed samples and the specific conditions of each sample.
Students formulate and discuss responses to the following question: What significance do you give to the presence of colic bacteria (specific for the flora of the human intestine) in water samples?

Filling in a K-W-L (Know-Want to know-Learned) table or diagram (if necessary / applicable).

Step 5 (1 min)

Final conclusions:

specifying the homework (if necessary / applicable – teacher can recommend some of the useful links, to be accessed and watched, and students could make notes, observations, comments, based on what they have seen and acknowledged).

oral or/and written appreciation (grades) for the students who answered during class.

Assessment

Oral current check
Systematic observation of students
Students who answered and showed interest, dedicated work, and seriousness in solving the given topics can be appreciated and marked with grades.

Useful links

English:

https://en.wikipedia.org/wiki/Bacillus_subtilis
https://biologydictionary.net/bacillus-subtilis/
bacillus microbiology lecture ||bacillus subtilis ||Easy Microbiology: https://www.youtube.com/watch?v=4_MZVdrYdeE
Four functions of Bacillus subtilis: https://www.youtube.com/watch?v=tSP0D3Pvgts
How to Grow Bacillus Subtilis: https://www.youtube.com/watch?v=LJuwTaHCskA
https://www.khanacademy.org/science/biology/bacteria-archaea/prokaryote-structure/v/bacteria
What are bacteria? - Science for Kids: https://www.youtube.com/watch?v=AaN8pSmtyV4
How to Grow Bacteria DIY Science Experiment with Ryan: https://www.youtube.com/watch?v=uuJxzNtHU74
Bacteria Around Us Experiment | Kingdoms and Classification | The Good and the Beautiful: https://www.youtube.com/watch?v=KY3usgmiifY
What are microorganisms? Bacteria, Viruses and Fungi: https://www.youtube.com/watch?v=9JW63U2mzqo
Microorganisms - What are Microorganisms? (Learning Videos For Kids): https://www.youtube.com/watch?v=GuwRiqETHF8
Viruses Vs. Bacteria - What are their differences?: https://www.youtube.com/watch?v=mQZDyLtCu5E
The Evolution of Bacteria on a “Mega-Plate” Petri Dish (Kishony Lab): https://www.youtube.com/watch?v=plVk4NVIUh8
The many roles of bacteria examined: https://www.britannica.com/video/83361/toxins-Bacteria-foods-food-poisoning-diseases-typhoid
Bacterial Structure and Functions: https://www.youtube.com/watch?v=b15Hy3jCPDs
What roles do bacteria, sweat glands, and skin play in the human immune system?: https://www.britannica.com/video/81336/bacteria-barriers-skin-human-body-lining-physiological
Bacteria: https://www.youtube.com/watch?v=h-z9-9OOWC4Romanian:

Romanian:

Bacteria: https://www.youtube.com/watch?v=37JD3fyd9mw
Sciences, 5th grade, Bacteria: https://www.youtube.com/watch?v=Z168xh7itr4
Bacteria (biology lesson): https://www.youtube.com/watch?v=TDoGrbpJJ14&t=6s
Introducative lesson about bacteria and hygiene: https://www.youtube.com/watch?v=NhQnw9wSAT4
Bacteria: https://www.youtube.com/watch?v=ORB866QSGv8
Immunity system explained I – Bacteria infection: https://www.youtube.com/watch?v=zQGOcOUBi6s

WORKSHEET

Experimental work highlighting bacterial cells

Required materials

To make the native preparation (with live germs): glass, straw (cereal stalks), water.
To make the microscopic preparation: microscope, slides, slides, pipette, basic fuchsin dye, methyl blue dye, filter paper.

Working method:

A. To make the native preparation:

Insert finely chopped hay straw (in a layer of 2-3 cm) into 4-6 numbered glasses, depending on the number of teams to be organized during class (P1, P2, P3, P4, P5, P6).
Pour lukewarm water (100 ml) into the corresponding glasses, 2-in 4 successive days (day 1, day 2, day 3, day 4).
Place the uncovered glasses in a lighted space, but not in contact with the sun, at a temperature of 20 degrees, for 48 hours.
The water in the glasses becomes opalescent and has a gelatinous film on the surface, with a metallic sheen
The solution indicates the presence of bacteria and some protozoa.

B. To make the microscopic preparation:

Step 1: Place a drop of the biological preparation on the slide with the pipette

Step 2: Cover with the lamella

Step 3: Remove excess water with filter paper

Step 4: Colour the preparation with fuchsin or methyl blue

Step 5: Place the preparation under the microscope

Step 6: Observe the preparation using objectives of different sizes

Step 7: Fill in the observation sheet

C. Organization of teams

Each group will make the microscopic preparation using the solution from the corresponding glass (team 1 – sample P1, team 2 – sample P2, etc.) as biological material.

OBSERVATION SHEET

Team Ti (i = 1, 2, …, 6) – microscopic preparation of Pi (i = 1, 2, …, 6)

In the realized microscopic preparation, we have identified:

Characteristics	Prokaryotes: ………………..	Eukaryotes: ……………………….
Form of organization
Dimension/Size (note the size category)
Number of individuals (low, high, ….)
Cell shape
Identified Cellular components: …………………………………. ………………………………….. Genetic material ………………………………….. Chloroplasts Organites (1) (organelle) for travel …………………………………… …………………………………… ……………………………………	- - - - - -	- - - - - -

Observation

(1) organelle = a specialized cellular part (such as a mitochondrion, chloroplast, or nucleus) that has a specific function and is considered analogous to an organ (https://www.merriam-webster.com/dictionary/organelle).

Erasmus+ Cooperation partnerships project

Sailing Into Opportunities

No. 2023-1-LT01-KA220-SCH-000161306

Funded by the European Union. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the National Agency. Neither the European Union nor National Agency can be held responsible for them.

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