Sections: Biology

Learning objective:

Know the mechanisms of hereditary variability, be able to predict the degree of risk of manifestation of hereditary pathology;

Educational: to introduce students to the forms of hereditary variability, their causes and effects on the body. To develop in schoolchildren the ability to classify forms of variability and compare them with each other; give examples illustrating the manifestation of each of them; develop knowledge about the types of mutations;

Developmental: continue the development of logical thinking, experimental and observational skills, the ability to generalize, draw conclusions, systematize material, work with a textbook, microscope.

Educational: continue to develop communication skills, correct mutual assessment, and the formation of a competent attitude towards the environment.

Equipment: tables; scheme; micropreparations: on chromosome variability, mutations in Drosophila flies; microscopes, digital microscope, computer, multimedia projector.

I. Assignment for self-preparation at home

A. It is necessary to repeat:

1. Structural levels of organization of hereditary material.
2. Structure of DNA and RNA.

B. Questions to be analyzed:

1. Forms of variability: phenotypic and genotypic. Their significance in ontogenesis.
2. Medical and genetic aspects of marriage.
3. Mutational variability. Classification of mutations: gene; chromosomal; genomic; mutations in germ and somatic cells.
4. Mutagenic factors. Mutagenesis and carcinogenesis. Antimutagens.
5. The concept of gene and chromosomal diseases.

II. Questions for frontal conversation:

1. What are the forms of variability in which the genotype changes?
2. What groups are mutations divided into depending on the level of changes and location?
3. List the types of chromosomal aberrations.
4. What is genomic variability associated with?
5. What changes in genetic material are observed during polyploidy?
6. What are the changes in the chromosome set during monosomy?
7. What are the changes in the chromosome set during trisomy?
8. What are the changes in the chromosome set during nullosomy?
9. What are the changes in the chromosome set during tetrasomy?
10. What are gene mutations associated with?
11. What is the difference between somatic and generative mutations?
12. What is induced mutagenesis?
13. How is the number of mutations related to a person's age?
14. Name the physical, chemical and biological factors of mutagenesis.
15. What are the main sources of mutagenic environmental pollution?
16. What diseases are called hereditary?
17. What are the manifestations of chromosomal abnormalities in Shereshevsky-Turner syndrome?
18. What are the manifestations of chromosomal abnormalities in Klinefelter syndrome?
19. What are the chromosomal abnormalities in Down syndrome?
20. Give examples of genetic diseases.
21. What are the ways to eliminate the danger of mutagenic environmental pollution?

III. Test control:

1.What variability is associated with changes in the number of chromosomes?

A). Gene mutations;
b). Combinative variability;
V). Modification variability;
G). Genomic mutations.

2.What genetic changes are observed with polyploidy?

A). Increase in the number of chromosome sets;
b). Increasing the number of chromosomes in a set;
V). Changes in the structure of individual chromosomes;
G). Change in gene structure.

3.Name the physical factors of mutagenesis:

A). Temperature;
b). Barometric pressure;
V). Ionizing radiation;
G). Ultraviolet radiation;
d). Vibration;
e). Ultra- and infrasound.

4.What is the manifestation of a change in the chromosome set during heteroploidy?

A). Change in the number of chromosome sets;
b). Change in the number of chromosomes;
V). Violation of the structure of chromosomes;
G). Changes in gene structure.

5.What type of variability reduces the number of chromosomes by one, two or three chromosomes?

A). Heteroploidy;
b). Polyploidy;
V). Chromosomal aberrations;
G). Gene mutations.

6.What type of variability changes the structure of DNA?

A). Chromosomal rearrangements;
b). Gene mutations;
V). Genomic mutations;
G). Polyploidy.

7.What is the name of the phenomenon in which part of a chromosome opens and joins a homologous chromosome?

A). Inversion;
b). Translocation;
V). Duplication;
G). Deletion.

8.What type of variability is associated only with the influence of the external environment?

A). Combinative;
b). Modification;
V). Gennaya;
G). Genotypic.

9.Name the factors under the influence of which biological mutagenesis occurs?

10.What changes in the chromosome set correspond to Down syndrome (disease)?

A). Monosomy for 10 pairs;
b). Trisomy 23;
V). Trisomy 21 pairs;
G). Monosomy of 21 pairs of chromosomes.

11.What chromosomal aberration causes a part of a chromosome to be lost?

A). Inversion;
b). Duplication;
V). Translocation;
G). Deletion.

If it is observed:

A). Members of the same generation of the same family;
b). In a series of generations of one family;
V). In one generation of different families;
G). Among generations of different families.

IV. The practical part of the work is the study of mutations.

1.Study the normal forms of the Drosophila fly.

Examine the external structure of the Drosophila fly on a microslide and determine the sex. Normal flies have a gray body covered with straight bristles; red eyes located on the sides of the head. The thoracic region consists of three segments, carries 3 pairs of limbs and a pair of transparent wings. The wings are elongated, smooth at the edges, their length exceeds the length of the body. There are stripes on the abdomen, the tergids are clearly visible. In the male, the chitinous plates at the end of the abdomen merge and have a solid dark color.

In your laboratory notebook, make a heading: Figure No. 1 “Female and male Drosophila fly.” Draw the normal shapes of fruit flies; In the figure indicate: male, female. Compare the drawings with photographs obtained from an electron microscope.

2. Using micropreparations, study the external structure of flies with various types mutations: yellow body, rudimentary wings, curved setae, absence of wings, notch on the wings. Compare the images with photographs taken from a digital microscope. In your notebook, complete: Figure No. 2 “Mutations in the Drosophila fly.” Draw different types of mutations.

3.Study chromosomal mutations (aberrations) on polytene (giant) chromosomes of the salivary glands of the Drosophila fly at the pachynema stage of the meiosis process. The cells of the salivary gland are large in size, the chromosomes are a thick thread, along the length of which chromomeres are visible (transverse striations in the form of dark and light stripes). The chromomeres of both chromosomes form a single line. Division can occur at the end of a chromosome or in the middle of it. The bivalent, homologous to the lost one, forms a loop. In your notebook, complete: Figure No. 3 “Chromosomal aberrations.” Draw and label: deletion, region of division of chromosomes with a deficiency, boundaries of a section of a normal chromosome homologous to the lost fragment, chromomeres, inversion, duplication.

4. Solve situational problems by determining the types of mutations and the reasons for their occurrence. Present your answers in table form.

Example of variability	Types of mutations	Causes of mutations
1. People with Down's disease, characterized by idiocy and a complex of other anomalies, have 47 chromosomes in their cells.
2. Some people have different eye colors, although such differences were not observed in their parents.
3. Albinism - lack of pigment in the skin, hair, cornea of ​​the eyes, is inherited as a recessive trait.
4.De Vries described giant shape Evening primrose. This plant has 28 chromosomes instead of 14.
5. A young couple who was exposed to radioactive radiation gave birth to a child with anomalies.
6. A brown-eyed couple gave birth to a blue-eyed child.

5. Fill out the table: “Comparative characteristics of the forms of variability

QUESTIONS for comparison	FORMS AND CHANGES
	Mutations			Modifications
	Genetic	Genomic	Chromosomal
Nature of variability
Causes
Effect on phenotype and genotype
Inheritance
Importance for the body
Implications for evolution

6.Topics for abstracts and project work:

A). The effect of radiation on living organisms.
b). Mutagenic factors of anthropogenic origin.
V). Induced mutagenesis.
G). Somatic and generative mutations.
d). Hereditary diseases.

The structure of plant and animal cells

Goal: find structural features of cells various organisms, compare them with each other

Progress:

1. Under a microscope, examine microscopic specimens of onion skins, yeast fungi, and cells of multicellular organisms

2. Compare what you see with the images of objects on the tables. Draw the cells in your notebooks and label the organelles visible under a light microscope.

3. Compare these cells with each other. Answer the questions. What are the similarities and differences between cells? What is

the reason for the similarities and differences between organisms?

Similarities	Reasons for similarity	Difference	Reasons for the difference
The cell is alive, growing, dividing. metabolism takes place. Both plant and animal cells have a nucleus, cytoplasm, endoplasmic reticulum, mitochondria, ribosomes, and Golgi apparatus.	Common origin of life.	Plants have a cell wall (made of cellulose), but animals do not. The cell wall gives plants additional rigidity and protects against water loss. Plants have a vacuole, but animals do not. Chloroplasts are found only in plants, in which organic substances are formed from inorganic substances with the absorption of energy. Animals consume ready-made organic substances that they receive from food.	Differences between plant and animal cells arose due to different developmental paths, nutrition, the ability of animals to move independently, and the relative immobility of plants.

Conclusion: Plant and animal cells are basically similar to each other, they differ only in those parts that are responsible for feeding the cell.

Laboratory work No. 3

Catalytic activity of enzymes in living tissues

Target: To develop knowledge about the role of enzymes in living tissues, to consolidate the ability to draw conclusions from observations.

Progress:

1) Prepare 5 test tubes and place:

First, add a little sand,

into the 2nd test tube, raw potatoes,

in the 3rd boiled potatoes,

into the 4th test tube raw meat,

in the 5th batch boiled meat.

Place a few drops of hydrogen peroxide into each test tube. Observe what happens in each test tube. Record the observation results in the table.

2) Grind a piece in a mortar raw potatoes with a little sand. Transfer the crushed potatoes along with the sand into a test tube and drop a little hydrogen peroxide into it. Compare the activity of the crushed tissue. Record the observation results in the table.

Tissue activity under different treatments.

3) Explain your results.

Answer the questions:

1) In which test tubes did enzyme activity manifest itself?

Activity appeared in test tubes 2,4,6, because these test tubes contained raw foods, and raw foods contain protein, the remaining test tubes contained boiled foods, and, as is known, in non-living - boiled foods, the protein was destroyed during cooking, and the reactions did not showed. Therefore, the body better absorbs foods containing protein.

2) How does enzyme activity manifest itself in living tissues?

In living tissues, when interacting with hydrogen peroxide, oxygen was released from the tissue, the protein was broken down to its primary structure and turned into foam.

3) How does tissue grinding affect enzyme activity?

When living tissue is crushed, activity occurs twice as fast as in non-crushed tissue, since the contact area between the protein and H2O2 increases.

4) Does the activity of the enzyme differ in living tissues of plants and animals?

In plant cells, the reaction occurs more slowly than in animal cells, because they have less protein, while in animal cells there is more protein and the reaction in them proceeds faster.

Conclusion: Protein is contained only in live foods, and in boiled foods the protein is destroyed, so no reaction with boiled foods and sand occurs. If you also crush the products, the reaction will proceed faster.

Laboratory work No. 4

Topic: identifying and describing the characteristics and similarities of human embryos and other vertebrates.

Goal: Identifying the similarities between the embryos of representatives different groups vertebrates as evidence of their evolutionary relationship.

Progress:

· Draw all 3 stages embryonic development different groups of vertebrates.

· Make a table indicating all the similarities and differences between embryos at all stages of development.

· Draw a conclusion about the evolutionary relationship of embryos, representatives of different groups of vertebrates.

Conclusion: similarities and differences between the embryos of representatives of different groups were revealed as evidence of their revolutionary kinship. Higher forms are more perfect.

Laboratory work No. 5

Topic: solving genetic problems and building a family pedigree

Goal: using test examples to consider the inheritance of characteristics, conditions and manifestations

Progress:

· Drawing up a family tree, starting with grandparents, if there is data, then with great-grandfathers.

· A light-skinned woman and a dark-skinned man got married. How many light-skinned children will there be in the third generation? Dark skin dominates light skin.

AA – dark skin – male

aa – light skin – woman

F 1 Aa Aa Aa Aa 100% - dark skin

F 2 AA Aa Aa aa 75% - dark skin

25% - light skin

AA x aa AA x Aa Aa x aa Aa x Aa

F 3 Aa Aa Aa Aa AA Aa AA Aa Aa Aa aa aa AA Aa Aa aa 81, 25% - dark skin

18.75% - light skin

Answer: 18, 75% - light skin

Conclusion: Signs change in accordance with the 1st and 2nd laws of Mendal.

· In humans, curly hair dominates over straight hair. Brown eyes dominate over blue ones. Freckles are also a dominant trait. If a man with curly hair, blue eyes and no freckles entered the tank. And a woman with straight hair, brown eyes and freckles. What possible combinations can children have?

Draw a conclusion about the variability of signs.

A - curly hair

a- straight hair

B- brown eyes

c- blue eyes

S-freckles

s- no freckles

	ABC	ABC	аВс	AvS	ABC	ABC
ABC	AASSVV	AaVvSS	AaVVSSs	AAVvSS	AABBSS	AaVvSs
ABC	AaVvSS	aavvss	aaVvSs	AawvSS	AaVvSs	aavvss
аВс	AaVVSSs	aaVvSs	aaBBSS	AaVvSs	AaBBSS	aaVvSs
AvS	AAVvSS	AawvSS	AaVvSs	ААввСС	AABvSs	AavvSss
ABC	AABBSS	AaVvSs	AaVVSSs	AABvSs	AABBss	AaVvSs
ABC	AaVvSs	aavvss	aaVvss	AavvSss	AaVvss	aawwss

75% curly hair

25% - straight hair

75% - brown eyes

25% - blue eyes

75% - with freckles

25% - no freckles

Conclusion: signs change in accordance with Mendal's 3rd law.

Laboratory work No. 6
Morphological characteristics of plants of different species.
Purpose of work: To ensure that students understand the concept morphological criterion species, consolidate the ability to draw up a distinctive characteristic of plants.
Progress:
1. Consider two types of plants, write down the names, and make a morphological description of the plants of each type. Describe the features of their structure (features of leaves, stems, roots, flowers, fruits).

2. Compare two types of plants, draw out similarities and differences. Make drawings of representative plants.

Setcreasia Syngonium

Laboratory work No. 7

Topic: Construction of a variation series and a variation curve

Goal: To become familiar with the patterns of modification variability and the methodology for constructing a variation series

Progress:

We count the number of variants of the attribute. We determine the average value of the attribute using the formula. Average value - M. Option - V. Frequency of occurrence of option - R. Amount - E. Total number variation series – n.

We build a variational line. We are building variation series variability. We draw a conclusion about the variability of the trait.

1.4	1.5	1.5	1.4	1.8	1.6	1.5	1.9	1.4	1.5	1.6	1.5	1.7	1.5	1.4	1.4	1.3	1.7	1.2	1.6
1.7	1.8	1.9	1.6	1.3		1.4	1.3	1.5	1.7	1.2	1.1	1.3	1.2	1.4	1.2	1.1		1.1	1.2

M length ==1.4

M width = =0.6

Conclusion: Average length value 1.4. Average width 0.6

Laboratory work No. 8

Topic: Adaptation of organisms to their environment.

Goal: to form the concept of the adaptability of organisms to their environment, to consolidate the ability to identify common features adaptability of organisms to their environment.

Progress:

1. Make drawings of the 2 organisms given to you.

Agama Caucasian Agama steppe

2. Determine the habitat of the organisms proposed for your research.

Agama Caucasian: Mountains, rocks, rocky slopes, large boulders.

Agama steppe: Sandy, clayey, rocky deserts, semi-deserts. They often settle near water.

3. Identify the features of adaptation of these organisms to their habitat.

4. Identify relative fitness patterns.

5. Based on your knowledge of the driving forces of evolution, explain the mechanism by which adaptations arise

6. Build a table.

Conclusion: organisms adapt to specific environmental conditions. This can be verified at specific example agam. Organisms' means of defense - camouflage, protective coloration, mimicry, behavioral adaptations and other types of adaptations - allow organisms to protect themselves and their offspring.

Laboratory work No. 9

Topic: Variability of organisms

Goal: to form the concept of variability of organisms, to continue work on the ability to observe natural objects and find signs of variability.

Progress:

· Make a drawing of the organisms given to you.

2. Compare 2-3 organisms of the same species, find signs of similarity in their structure. Explain the reasons for the similarity of individuals of the same species.

Signs of similarity: leaf shape, root system, long stem, parallel veining of leaves. The similarity of these plants suggests that they have the same hereditary characteristics.

3. Identify signs of difference in the organisms being studied. Answer the question: what properties of organisms cause differences between individuals of the same species.

Signs of difference: width and length of the leaf blade, stem length. Plants of the same species have differences because they have individual variability.

4. Reveal the significance of these properties of organisms for evolution. Which differences, in your opinion, are due to hereditary variability, and which – to non-hereditary variability? Explain how differences could arise between individuals of the same species?

Thanks to heredity, organisms pass on their characteristics from generation to generation. Variability is divided into hereditary, which provides material for natural selection, and non-hereditary, which arises due to changes in factors environment and helps the plant adapt to these conditions.
Differences that are due to hereditary variability: flower shape, leaf shape. Differences that are not due to hereditary variability: leaf width and length, stem height.
Differences between individuals of the same species could occur due to different conditions their environment, as well as due to different plant care.

5. Define variability.

Variability is a universal property of living organisms to acquire new characteristics under the influence of the environment (both external and internal).

Conclusion: we formed the concept of variability of organisms, continued work on the ability to observe natural objects and find signs of variability.

Laboratory work No. 10

Goal: Learn to understand hygiene requirements in the classroom

Completing of the work:

· Pour exactly 10 ml of the prepared solution into the flask.

· Using a syringe, draw in 20 ml of outside air

We introduce air into the cone through the needle

· Disconnect the syringe and quickly close the needles with your finger

· The solution is whipped until carbon dioxide is absorbed (gradual discoloration of the solution occurs)

· Air is introduced until (gradually adjusting its quantity) until the solution is completely discolored

· After the solution has become discolored, it is poured out of the flask, washed with distilled water and again filled with 10 ml of the specified solution

· The experiment is repeated, but the air of the audience is used

· The percentage of carbon dioxide is determined by the formula:

A is the total volume of atmospheric air passed through the cone.

B is the volume of audience air passed through the cone

0.03% - approximate level of carbon dioxide in the atmosphere (constant level)

· Calculate how many times more carbon dioxide is in the classroom than in the air outside

· Formulate hygiene rules based on the results obtained.

· It is necessary to carry out long-term ventilation of all rooms. Short-term ventilation is weakly effective and practically does not reduce the carbon dioxide content in the air.

· It is necessary to plant greenery in the classrooms. But the absorption of excess carbon dioxide from the air by indoor plants occurs only in the light.

· Children studying in classrooms with high concentrations of carbon dioxide often experience heavy breathing, shortness of breath, dry cough and rhinitis, these children have a weakened nasopharynx.

An increase in the concentration of carbon dioxide indoors leads to asthma attacks in asthmatic children.

Due to increased concentrations of carbon dioxide in schools and higher education educational institutions The number of students missing lessons due to illness is increasing. Respiratory infections and asthma are the main diseases in such schools.

Increasing the concentration of carbon dioxide in the classroom negatively affects children's learning outcomes and reduces their performance.

· Without ventilation of rooms, the concentration of harmful impurities in the air increases: methane, ammonia, aldehydes, ketones coming from the lungs during breathing. In total, about 400 harmful substances are released into the environment with exhaled air and from the surface of the skin.

· The danger of carbon dioxide poisoning occurs during combustion, fermentation in wine cellars, in wells; Carbon dioxide poisoning is manifested by palpitations, tinnitus, and a feeling of pressure on the chest. The victim should be taken out into fresh air and resuscitation measures should be started immediately.

During the learning process, the student can perform practical and laboratory work. What is their specificity? How is practical work different from laboratory work?

What are the features of practical work?

Practical work- this is an assignment for a student that must be completed on a topic determined by the teacher. It is also expected to use the literature recommended by him in preparation for practical work and a plan for studying the material. The task in question in some cases includes an additional test of the student’s knowledge - through testing or, for example, writing a test.

The main purpose of the practical work consists in developing in the student practical skills related to the generalization and interpretation of certain scientific materials. In addition, it is expected that the results of practical exercises will subsequently be used by the student to master new topics.

The task of a teacher who helps prepare students for events about which we're talking about, consists in drawing up a consistent algorithm for students to master the necessary knowledge, as well as in selecting methods for objective assessment of relevant knowledge. In this case it is possible individual approach, when the student’s skills are tested in the way that is most comfortable for the student in terms of presenting information to the teacher. Thus, some students are more comfortable with the written form of knowledge testing, while others prefer the oral form. The teacher can take into account the preferences of both.

The results of the practical lesson most often do not affect the student’s subsequent grade in the exam. During this event, the teacher’s task is to understand the current level of knowledge of students, identify errors that characterize their understanding of the topic, and help correct shortcomings in the development of knowledge - so that already at the exam the student will present a more correct understanding of the topic.

What are the features of laboratory work?

Under laboratory work Most often it is understood as an educational lesson, within the framework of which one or another scientific experiment is carried out, aimed at obtaining results that are important from the point of view of students’ successful mastery of the curriculum.

During laboratory work, the student:

• studies the practical course of certain processes, explores phenomena within the framework of a given topic - using methods mastered in lectures;
• compares the results of the work obtained with theoretical concepts;
• interprets the results of laboratory work, evaluates the applicability of the data obtained in practice, as a source of scientific knowledge.

In some cases, students are required to defend their laboratory work, in which a certain audience of students is presented with the details of the research, as well as evidence of the legitimacy of the conclusions the student came to. Often the defense of laboratory work is carried out through individual interaction between the student and the teacher. In this case, based on the results of the study, the student generates a report (according to an established or independently developed form), which is sent for verification by the teacher.

It should be noted that successful completion of laboratory work, as a rule, is an important criterion for the successful passing of exams by a student. The teacher considers giving high grades to students only if they are able to present practical results of applying the knowledge gained in lectures before taking the exam.

Comparison

The main difference between practical work and laboratory work is the purpose of their implementation. Thus, typical practical work is initiated by the teacher mainly to test the amount of knowledge, laboratory work is initiated to assess the ability of students to apply acquired knowledge in practice, during an experiment.

Another criterion is the limited influence of the results of practical work on the student’s final grade. In turn, typical laboratory work, as we noted above, can be the most important factor in a student’s success in passing the exam.

Typical laboratory work is typical mainly for natural science disciplines - physics, chemistry, biology. Practical - conducted as part of training in various scientific fields, including the humanities.

Differences between the works in question can also be traced at the level of methods for testing students' knowledge. In the case of practical work, this is an oral or written survey, testing. During laboratory activities, a tool for testing a student’s knowledge can be the procedure for protecting research results.

It is worth noting that laboratory and practical work have a number of common features. Such as, for example:

1. implementation in accordance with the plan recommended by the teacher, as well as using a given list of literary sources;
2. focus on identifying the student’s current level of knowledge.

Having determined what the difference is between practical and laboratory work, we will record the conclusions in the table.

Table

Practical work	Laboratory work
What do they have in common?
Practical and laboratory work are similar in many ways (both involve execution according to plan, focus on assessing the student’s knowledge)
What is the difference between them?
Aimed at assessing the level of current knowledge of the student	The goal is to obtain concrete results from the application of students’ existing knowledge
Can be taught in a wide range of disciplines	Carried out, as a rule, within the framework of teaching natural science disciplines
Usually does not affect the student's prospects for passing the exam	Is an important factor in students receiving high marks in the exam
Knowledge testing is carried out through oral or written questioning, testing	Knowledge testing is carried out during the defense of laboratory work

Modification variability An important role in the formation of the characteristics of an organism is played by its habitat. Each organism develops and lives in a certain environment, experiencing the action of its factors that can change the morphological and physiological properties of organisms, i.e. their phenotype.

ASSIGNMENT Complete the lab using the information on the slides and additional material. To do this: Write down the topic and purpose of the work. Select an object to determine the statistical patterns of the characteristic ( indoor plant, physiological indicators of classmates, etc.) During the work, describe the features of modification variability. Construct a variation series and a variation curve, calculate the average value of the characteristic being studied using the proposed statistical data and complete the individual part of the work. Draw a conclusion (answer to the stated goal of the work). Complete the reporting task. SUCCESSFUL WORK!

Modification variability Statistical patterns of modification variability. Modification variability of many characteristics of plants, animals and humans obeys general laws. These patterns are identified based on the analysis of the manifestation of the trait in a group of individuals (n). The degree of expression of the studied trait among members of the sample population is different. Each specific meaning The characteristic being studied is called a variant and is designated by the letter v. When studying the variability of a trait in a sample population, a variation series is compiled in which individuals are arranged in ascending order of the indicator of the trait being studied.

Modification variability Based on the variation series, a variation curve is constructed to graphically display the frequency of occurrence of each variant. The frequency of occurrence of individual variants is denoted by the letter p. For example, if you take 100 ears of wheat (n) and count the number of ears in the ear, then this number will be from 14 to 20; this is the numerical value of option (v). Variation series: v = Frequency of occurrence of each variant p = The average value of the characteristic occurs more often, and variations significantly different from it are much less common. This is called a normal distribution. The curve on the graph is usually symmetrical. Variations, both larger than average and smaller, occur equally frequently.

Modification variability It is easy to calculate the average value of this characteristic. To do this, use the formula: (v ּp) M = n where M is the average value of the characteristic, the numerator is the sum of the products of the variant by their frequency of occurrence, the denominator is the number of variants. For this characteristic, the average value is 17.13. Knowledge of the patterns of modification variability is of great practical importance, since it allows one to anticipate and plan in advance the degree of expression of many characteristics of organisms depending on environmental conditions (give specific examples).

Compression strength was measured in two parallel ninth grades right hand 50 boys. The results are as follows: Boys' grip strength, kg 29, 25 33, 34, 33, 34, 34, 33 35, 38, 37, 35, 38, 37, 38, 36, 38, 39 41, 41, 44, 42, 41 , 42, 44, 43, 44, 41, 41 46, 45, 48, 49, 45, 46, 45, 47, 45, 49, 45, 47 51, 54, 50, 54, 53, 51 55, Using this digital material, complete the following tasks: 1. Make a variation series of the variability of the compression strength of the students’ right hand using the table (next slide).

Answer the questions: a) are there limits to the manifestation of the trait? b) which attribute values ​​occur more often and which less frequently? c) how much data needs to be processed in order to identify a pattern? d) what practical significance does the study of this trait have? Draw a conclusion.

Conclusions: 1. The manifestation of the trait does not go beyond the reaction norm, which is determined by the genotype. 2. Among the indicators of variability of a given trait, the average values ​​of the trait are most common, and the minimum and maximum manifestations of the trait occur as exceptions. 3. Modification variability is characterized by statistical patterns; the average value of the characteristic is detected only with mass calculations (The more data, the more clearly the pattern appears). 4. Modification variability plays a huge role in human practical activity (The genetic capabilities of a variety and breed are maximally manifested in optimal conditions). “The program of action of genes in the genotype system resembles the score of a symphony. This score is written in notes in the form of genes. The composer is an evolutionary process, the orchestra is a developing organism, and the conductor of a symphony is external environment" (Russian geneticist M. E. Lobashov). EXPLAIN HOW YOU UNDERSTAND THE SUGGESTED EXPRESSION. GIVE SPECIFIC EXAMPLES

Complete test 1. What is modification variability called? a) combinative b) hereditary c) non-hereditary d) individual 2. What are the characteristics of modification variability? a) depend on the environment b) can be beneficial and harmful c) arise suddenly d) are dominant and recessive 3. The manifestation of which trait cannot be attributed to modification variability? a) the height of students of the same age b) the size of the diameter of potato tubers c) the weight of bean seeds d) the color of a white crow

4. What are the features of modification variability? a) manifests itself individually in each individual, because the genotype changes b) is adaptive in nature, the genotype does not change c) does not have an adaptive nature, caused by a change in the genotype d) obeys the laws of heredity, the genotype does not change 5. Modification variability a) is of a group nature b) is of an individual nature c) inherited d) changes the genotype An increase in body weight in domestic animals with a change in diet is classified as variability: a) modification b) cytoplasmic c) genotypic d) combinative

Laboratory work concept

An analysis of the literature on didactics and methods of teaching mathematics allows us to see the multifaceted nature of such a concept as laboratory work. Laboratory work can act as a method, form and means of teaching. Let's take a closer look at these aspects:

1. Laboratory work as a teaching method;

2. Laboratory work as a form of training;

3. Laboratory work as a teaching tool.

Laboratory work as a teaching method

Teaching method is the ways of interaction between teacher and students, aimed at achieving the goals of education, upbringing and development of schoolchildren during training.

IN pedagogical activity many generations have accumulated and continue to be replenished big number techniques and teaching methods. To comprehend, generalize and systematize them, various classifications of teaching methods are carried out. When classifying by sources of knowledge, verbal (story, conversation, etc.), visual (illustrations, demonstrations, etc.) and practical teaching methods are distinguished.

Let's take a closer look at practical teaching methods. They are based on the practical activities of students. With their help they develop practical skills and abilities. The methods considered include exercises, laboratory and practical work. It is necessary to distinguish them from each other.

In the literature, exercise is understood as repeated performance of educational actions in order to develop skills and abilities. Requirements for the exercise: the student’s understanding of goals, operations, results; correction of execution errors; bringing implementation to a degree that guarantees sustainable results.

The purpose of practical work is to apply knowledge, develop experience and skills, and develop organizational, economic and other skills. When performing such work, students independently practice practical application acquired theoretical knowledge and skills. The main difference between laboratory and practical work is that laboratory work The dominant component is the process of developing experimental and, in practical, constructive skills of students. Note that experimental skills include the ability to independently simulate an experiment; process the results obtained during the work; ability to draw conclusions, etc.

In addition, laboratory work should be distinguished from demonstration experiments. During the demonstration, the teacher himself performs the corresponding experiments and shows them to the students. Laboratory work is performed by students (individually or in groups) under the guidance and supervision of a teacher. The essence of the laboratory work method is that students, having studied theoretical material, under the guidance of a teacher, perform practical exercises to apply this material in practice, thus developing a variety of skills.

Laboratory work is a teaching method in which students, under the guidance of a teacher and according to a predetermined plan, carry out experiments or perform certain practical tasks and in the process perceive and comprehend new things. educational material, consolidate previously acquired knowledge.

Conducting laboratory work includes the following methodological techniques:

1) setting the topic of classes and determining the objectives of laboratory work;

2) determining the order of laboratory work or its individual stages;

3) direct performance of laboratory work by students and teacher monitoring of the progress of classes and compliance with safety regulations;

4) summing up the laboratory work and formulating the main conclusions.

Let's consider another classification of teaching methods, which includes the laboratory method. The basis of this classification is the method of knowledge control. There are: oral, written, laboratory and practical.

Oral knowledge control involves the student’s oral response to questions posed in the form of a story, conversation, or interview. Written - involves the student’s written response to one or a system of assignment questions. Written answers include: homework, test, control; written answers to test questions; dictations, abstracts.

The laboratory-practical method includes independent performance by a student or a group of students of laboratory or practical work. The teacher in this case plays the role of a guide - he explains what needs to be done and in what order. The result of laboratory work depends on the schoolchildren themselves, on their knowledge and ability to apply it in their practical activities.

Laboratory work as a teaching method is largely of a research nature, and in this sense is highly valued in didactics. They awaken students' deep interest in surrounding nature, the desire to comprehend, study surrounding phenomena, apply acquired knowledge to solve both practical and theoretical problems. Laboratory work helps familiarize students with the scientific foundations of modern production, instruments and tools, creating the prerequisites for technical training.

Thus, the purpose of using this method in a mathematics lesson, there is the clearest presentation, consolidation of the material being studied, and increased interest in the subject.

At the same time, it is important not to forget that when conducting laboratory work, a lot of attention and concentration of students is required during the execution process, which is not always possible. In addition, preparing laboratory work requires a lot of time from the teacher. Also, the use of such works will permanently reduce the interest of students in the subject due to the monotony of methods. Therefore, the use of laboratory work is possible as a variety of student activities, and only in those cases where it will be the most effective way achieving the goal.