After work
· Set the handles of the devices to their original position, turn off the unit, remove the plugs of the devices from the sockets.
· Return the received accessories to the laboratory assistant.
The student's activity in the lesson consists of the following actions:
1) admission to the lesson;
2) performance of work;
3) implementation of calculations, obtaining a result;
4) registration of a written reading.
The admission to work is to clarify the students' knowledge of theoretical material, understanding of the purpose of the work, knowledge of the experimental setup. Preparing the student for the lesson is that he carefully reads everything that is written about this work in this manual. After that, it is necessary to refer to the literature indicated in the recommendations in order to get acquainted with the theory of the studied phenomenon in more detail and answer the control questions for work, the student prepares the answers to the control questions at home. The teacher makes an entry in his journal about the admission of a student to experimental work. After admission, the student receives the initial data from the teacher and proceeds to work. First of all, you need to make sure that you have all the accessories you need to complete it.
In the course of the student's work, the teacher supervises the student's experimental work, the production of measurements, the recording of their results and endorses the obtained results in the student's laboratory notebook. Then the obtained measurement results are processed mathematically: the average values are found, the desired physical quantity is calculated, the errors are calculated, the final result is recorded, which is shown to the teacher and evaluated by him.
To receive credit, a student must have a written report on the work, which is drawn up in a laboratory notebook. A written reading should contain all the items that are indicated in a single description of laboratory work (see below).
1. Title page according to the sample.
2. The purpose of the laboratory work.
3. Devices and accessories.
4. Diagram or drawing of the installation (with an inscription and explanation of all elements included in the diagram), as well as drawings explaining the conclusion of working formulas.
5. Basic calculation formulas, with the obligatory explanation of the values included in the formula.
6. Tables.
7. Examples of calculation.
8. If required according to the assignment - graphs and diagrams.
9. Conclusion on laboratory work is required.
Conclusions on laboratory work - briefly formulated results of processing the results of measurements - should be given in the section "Results of processing measurements and conclusions" of the synopsis for each task of the laboratory work. The following information should be displayed in the conclusions:
· What was measured and by what method;
What charts were built;
· What results were obtained.
Also, the conclusions should contain a discussion of the plotted graphs and the results obtained: whether the form of the experimental graphs coincides with theoretical predictions and whether the results of the experiment coincide with the theory. The recommended form for presenting the conclusions on the graphs and on the answer is given below.
Practical and laboratory work is carried out in biology in accordance with the calendar-thematic planning, in accordance with the requirements of the curriculum in biology.
The teacher informs the students in advance about the schedule for these works.
A grade for laboratory work is given to each student who was present at the lesson when this work was carried out.
Practical and laboratory work can be carried out both individually and for a couple or group of students.
Municipal budgetary educational institution
"Torbeevskaya average comprehensive school No. 1 "
Performance:
"Exchange of experience in the assessment of laboratory work of students in biology"
Prepared by: teacher of biology Mishina E.A.
rp Torbeevo 2014
Practical and laboratory work is carried out in biology in accordance with the calendar-thematic planning, in accordance with the requirements of the curriculum in biology.
The teacher informs the students in advance about the schedule for these works.
A grade for laboratory work is given to each student who was present at the lesson when this work was carried out.
Practical and laboratory work can be carried out both individually and for a couple or group of students.
At the end of each labmust be recorded conclusion based on the results of the work performed (the conclusion is formulated based on the purpose of the work).
Lab work without inference may not be appreciated.
When assessing the effectiveness of the implementation of practical and laboratory work, the teacher uses the following criteria:
1) correctly defined the purpose of the experiment;
2) performed work in in full in compliance with the required sequence of experiments and measurements;
3) independently and rationally chose and prepared for the experience necessary equipment, all experiments were carried out in conditions and modes that ensure the receipt of results and conclusions with the greatest accuracy;
4) scientifically competently, logically described the observations and formulated conclusions from the experience. In the presented report, he correctly and accurately completed all records, tables, figures, drawings, graphs, calculations and made conclusions;
5) correctly performed the error analysis (grades 9-11).
6) demonstrates organizational and labor skills (maintains a clean workplace and order on the table, economically uses consumables).
7) the experiment is carried out according to the plan, taking into account safety measures and the rules for working with materials and equipment.
Grade "4" is given if the student has fulfilled the requirements for grade "5", but:
1.the experiment was carried out under conditions that do not provide sufficient measurement accuracy;
2. or two or three shortcomings were made;
3.or no more than one blunder and one defect,
4. or the experiment is incomplete;
5. or made inaccuracies in the description of observations from experience, made incomplete conclusions.
1. correctly defined the purpose of the experiment; does the work correctly at least half, however, the volume of the completed part is such that it allows you to get the correct results and conclusions on the main, fundamentally important tasks of the work;
2. or the selection of equipment, objects, materials, as well as work on the beginning of the experience was carried out with the help of a teacher; or in the course of the experiment and measurements, mistakes were made in the description of observations, in the formulation of conclusions;
3. the experiment was carried out in irrational conditions, which led to obtaining results with a greater error; or were admitted in the report total no more than two errors (in records of units, measurements, in calculations, graphs, tables, diagrams, analysis of errors, etc.) of a nature not fundamental for this work, but influencing the result of execution; either the error analysis was not performed at all or was performed incorrectly (grades 9-11);
4. makes a gross error during the experiment (in the explanation, in the design of the work, in the observance of safety rules when working with materials and equipment), which is corrected at the request of the teacher.
1. did not independently determine the purpose of the experiment; did not complete the work completely, did not prepare the necessary equipment and the volume of the completed part of the work does not allow making the correct conclusions;
2. or experiments, measurements, calculations, observations were made incorrectly;
3. or in the course of work and in the report, all the deficiencies noted in the requirements for the assessment of "3" were discovered in the aggregate;
4. makes two (or more) gross mistakes in the course of the experiment, in the explanation, in the design of the work, in the observance of safety rules when working with substances and equipment, which cannot be corrected even at the request of the teacher.
1. completely failed to start and formalize the experience; does not do the job; shows the lack of experimental skills; did not comply or grossly violated labor safety requirements.
Assessment of observation skills.
Grade "5" is given if the student:
2. highlighted the essential features of the observed object (process);
3. logically, scientifically competently formalized the results of observations and conclusions.
Grade "4" is given if the student:
1. correctly conducted the observation as instructed by the teacher;
2. when identifying essential features of the observed object (process), named minor ones;
3) allowed negligence in the execution of observations and conclusions.
Grade "3" is given if the student:
1. made inaccuracies and 1-2 mistakes in conducting observations on the instructions of the teacher;
2. when identifying essential features of the observed object (process), selected only a few;
3) made 1-2 mistakes in the design of observations and conclusions.
Grade "2" is given if the student:
1. made 3 - 4 mistakes in conducting observations on the instructions of the teacher;
2. incorrectly identified the signs of the observed object (process);
3. omitted 3 - 4 errors in the design of observations and conclusions.
Grade "1" is given if the student:
Does not possess the ability to conduct surveillance.
As a rule, during practical and laboratory work, tasks are not differentiated by levels, therefore, the assessment of the results of the completed task is carried out by the teacher on the basis of the proposed criteria.
Conclusions on laboratory work - briefly formulated results of processing the results of measurements - should be given in the section "Results of processing measurements and conclusions" of the synopsis for each task of the laboratory work. The following information should be displayed in the conclusions:
what was measured and by what method;
what charts were drawn;
what results were obtained.
Also, the conclusions should contain a discussion of the plotted graphs and the results obtained: whether the form of the experimental graphs coincides with theoretical predictions and whether the results of the experiment coincide with the theory. The recommended form for presenting the conclusions on the graphs and on the answer is given below.
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OUTPUT BY SCHEDULE (template): Experimentally obtained dependence graph function name in words from argument name has the form of a straight line (parabola, hyperbola, smooth curve) and qualitatively coincides with the theoretical dependence of these characteristics, which has the form formula(if the type of dependence is unknown, then it is not necessary to give it). |
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OUTPUT BY ANSWER (pattern): The experimentally obtained value of the quantity full name of the physical characteristic equal to symbol = (the average ± error) ·10 degree unit(δ = ___%), within the error limits coincides (does not coincide) with the tabular (theoretical) value of this quantity, equal to number, unit. |
1. Graphs are drawn in pencil on graph paper or on a sheet of paper with a size of at least ½ of a notebook sheet.
2. A rectangular coordinate system with UNIFORM axis marking. Argument values are plotted along the X-axis, and function values are plotted along the Y-axis.
3. The scale and origin of coordinates are chosen so that the experimental points are located over the entire area of the drawing.
4. The scale unit must be a multiple of 1 × 10 n, 2 × 10 n 3 × 10 n etc., where n= …-2, -1, 0, 1, 2, ….
5. Next to the axis, the letter designation, order and dimension of the physical quantity are given.
6. Under the chart - the full name of the chart WORDS.
7. No lines and marks, explaining the construction of points on the graph, can be drawn.
Examples:
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RIGHT |
WRONG |
TO
Report
for laboratory work No.
«__________________________________________________________ __________________________________________________________»
Completed Art. group
____________________________
Lecturer (academic, title)
____________________________
EXAMPLE OF LABORATORY REPORT
State autonomous educational institution of the Astrakhan region of higher professional education
"Astrakhan Civil Engineering Institute"
TOafedra Physics and mathematics, information technology
Report
for laboratory work No. 1.2.
STUDY OF ERRORS OF ACCELERATION MEASUREMENT
FREE FALL WITH THE HELP OF A MATHEMATICAL PENDULUM "
(name of laboratory work)
Completed Art. PGS groups - 11-10
Ivanov Ivan Ivanovich
Lecturer: Ph.D., Assoc.
_____Petrov Sergei Ivanovich
1.09.11 Petrov
1.09.11 Petrov
5.09.11 Petrov
Objective: 1) studying the oscillations of a mathematical pendulum: measuring the period of its oscillations and determining the acceleration of gravity;
2) assessment of random and instrumental measurement errors; study of the dependence of the width of the confidence interval on the number of experiments and confidence probability.
Experimental setup diagram
1 - tripod;
2 - thread lengthl;
3 - cargo;
4 - stopwatch;
5 - centimeter tape
Calculation formulas
,
;
g – acceleration of gravity;
l – thread length;
N – the number of oscillations in time t.
Thread length measurement result: l= 70.5 cm = 0.705 m.
Calculation of the constant C
С = (2 5) 2 0,705 = 695,807 696 (m).
Exercise 1. ERROR ASSESSMENT
RESULT 25 MEASUREMENTS
Table 1
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Experiment number | ||||
Laboratory work in biology.
Laboratory work No. 1.
Topic: "The composition of the seeds."
Look at the chart on the board. Name the parts of the seed. Draw a conclusion why, by studying the composition of seeds, we can judge the chemical composition of a plant.
1. Observing safety rules, light an alcohol lamp and warm up a test tube with seeds. Place a microscope slide to the opening of the tube. What are you seeing?
2. Continuing heating, see what changes occur to the seeds (color, smell). Make a conclusion.
3. Using personal experience, guess what happens next. Stop heating, close the alcohol lamp, place the test tube in the rack. On your own or using the text of the textbook (p. 10), draw up a diagram in the notebook “ Chemical composition cells ". Cross-check the notebooks and compare with the chart on the chalkboard.
Laboratory work No. 2.
Topic: "Determination of the physical properties of proteins, fats and carbohydrates (starch, sugar).
1. Add water to a little wheat flour and make a lump of dough. How has the dough changed?
2. Wrap a lump of dough in cheesecloth, put it in a glass of water and rinse it. How has the water in the glass changed?
3. Put 1-2 drops of iodine solution into a glass with clean water... How did the color of the water change?
4. Drop 1-2 iodine into a glass of water into which the dough was dipped. How did the color of the glass content change? What conclusion can be drawn?
5. Place the sunflower seed between two sheets of white paper; press down hard on the seed with the blunt end of a pencil. What happened to the paper? What conclusion can be drawn?
6. Discuss which physical properties organic substances can be investigated in what way. Enter the obtained data into the table.
Laboratory work No. 3.
Topic: "The structure of the cell."
1. Read the first two paragraphs on p. 16 textbooks and make a diagram of life forms in a notebook. Give brief description each group and provide examples of representatives.
2. Set up the microscope and prepare the onion skin preparation. Draw a drawing in your notebook. What are the clearly visible parts of the cage?
3. Knowing the functions of nucleic acids, think about what role the nucleus can play in the cell?
4. Think, why in the germ cells there is a single set of chromosomes, and in the cells of the body there is a double? What happens if the set of chromosomes changes?
Laboratory work No. 4.
Topic: "Plant tissue".
1. Consider whether all cells in a multicellular organism are the same in structure. Justify the answer.
2. Find in the textbook on p. 30 definition of tissue, write down the types of plant tissues in a notebook.
3. Consider the finished tissue micropreparations, make the necessary sketches, formulate a conclusion about the relationship between the structure of cells and the function to be performed.
4. Answer the question: are all cells of the same structure in a multicellular plant organism?
Laboratory work No. 5.
Topic: "Animal tissue".
1. Using the textbook, p. 32-34, write down the types of animal tissue.
2. Consider the slides of these tissues.
3. Make a conclusion about the relationship between the structure and function of cells.
4. Are animal tissues different from plant tissues? Why?
Laboratory work No. 6.
Topic: "The structure of root systems."
1. Consider the root systems of rye and beans.
2. Find the adventitious and lateral roots in the rye root system. Can you find the main root in it?
3. What is the name of the rye root system? Sketch and label parts of it.
4. Locate the main root in the bean root system.
5. Sketch the bean root system. Write down parts of it. What is the name of this type of root system?
Laboratory work No. 7.
Topic: "Microscopic structure of the root."
1. Look under the microscope the preparation "Cellular structure of the root tip", compare with the picture on p. 42 textbooks, select the root zones, name their functions.
2. Using your practical experience, name the functions of the root. Write it down in a notebook.
Laboratory work No. 8.
Topic: "The structure and location of the kidneys."
1. Consider the herbariums and plants offered to you. What kidneys do you see? How are they located? Draw a drawing.
2. Find small elongated and rounded buds on the shoot. Draw a drawing.
3. Using the dissecting knife, make a longitudinal incision of the rounded kidney. Using a magnifying glass and dissecting needles, examine its internal structure. What is the name of this kidney? Draw a drawing.
4. Using the dissecting knife, cut along the smaller, elongated kidney. Using a magnifying glass and dissecting needles, examine its structure. What is the name of this kidney? Draw a drawing.
5. Why is a bud called a rudimentary shoot?
Laboratory work No. 9.
Topic: "Simple and complex leaves."
1. Consider carefully the leaves offered to you, divide them into groups and explain by what principle you classified them. Justify the answer.
2. Sketch in a notebook the petioled, sedentary, compound sheet... Sign the drawings.
3. Consider the arrangement of the leaves on the plant or herbarium. Compare with the location of the kidneys. Make a conclusion.
draw in a notebook petiolate, sedentary. am leaves, divide them into groups and explain how you classified them
Laboratory work No. 10.
Topic: "The structure of a flower."
1. Examine the flower, holding it by the stalk. Pay attention to its size, color, smell, number of parts, think about its importance for plant life.
2. Carefully separate the perianth on a piece of paper.
3. Select the main parts of the flower: stamens, pistil. Consider how they work.
4. Write down the names of the parts of the flower on a piece of paper and arrange them according to the names (you can use the text of the textbook on p. 40).
5. Draw a diagram of the structure of the flower in a notebook and sign it. Make a conclusion about the role of the flower in the life of the plant.
Laboratory work No. 11.
Topic: "Dry and juicy fruits"
1. Using personal experience and the text of the textbook (p. 40, second paragraph from the bottom), tell us about the methods of pollination of plants. What happens after pollination with a flower? How is the fetus formed?
3. Fill in the table, give examples of fruits and plants in which they are found, draw a conclusion about the significance of fruits in the life of plants.
Variety of fruits.
Laboratory work No. 12.
Topic: "The structure of seeds of dicotyledonous and monocotyledonous plants."
1. Review and describe appearance bean seeds. Draw a drawing.
2. Use a dissecting knife to remove the seed skins. What is its role for the seed?
3. Consider the structure of the embryo. Draw a drawing, sign its main parts.
4. Review and describe the appearance of the wheat caryopsis. Draw a drawing.
5. Try to remove the caryopsis cover with a dissecting needle.
6. Using the picture of the textbook and the finished preparation “Wheat grain. Longitudinal section ", which you can examine in a dissecting magnifier, make a drawing" The structure of wheat kernels "; write down the main parts.
7. Compare the structure of a bean seed and a wheat caryopsis. Find similarities and differences.
8. Fill in the diagram:
Laboratory work No. 14.
Topic: "The movement of solutions along the stem"
1. Compare the movement of substances along the trunk of a tree with their movement along the stem of a potato (textbook, pp. 74 and 75). Make a movement diagram in a notebook.
2. Consider the micropreparation "Vascular-fibrous bundle of the linden trunk", compare with the pictures of the textbook on p. 74 and 75, with a cut of a potato tuber. Sketch the vascular fibrous bundles in a notebook and sign the drawing.
Laboratory work No. 15.
Topic: "The structure of the blood cells of frogs and humans."
1. Look at micropreparations of human and frog blood, compare their sizes and draw a drawing in a notebook. Compare with the picture in the tutorial.
2. Make conclusions about what you saw.
Laboratory work No. 16.
Topic: "Bone structure".
1. Consider the suggested animal bones. Determine whose bones it is, what they are called. Divide them into groups by size, structure.
2. Using the drawing of the textbook, name the parts of the bone, make a drawing "The structure of the bone" in the notebook, sign it.
Laboratory work No. 17.
Topic: "The movement of ciliates, shoes and earthworms."
1. Pipette a drop of the finished shoe culture onto the slide.
2. Cover the drop with a coverslip. Remove excess water with filter paper.
3. Examine the specimen under a microscope (objective 20, eyepiece 15).
4. Observe the beating of the cilia.
5. Sketch the appearance of the infusoria.
6. Draw and describe the stages in the movement of the earthworm.
