Unified State Exam. Biology. Solving tasks of increased and high level of complexity. How to get the maximum score. Kalinova G.S. Biology How the tasks in biology are assessed

Municipal budgetary educational institution

"Secondary school No. 4 of Shebekino, Belgorod region"

Features of the solution and assessment of tasks 22-28 USE in biology

Prepared by: Arnautova Natalia Zakharovna,

chemistry and biology teacher

MBOU "School No. 4, Shebekino, Belgorod Region"

2017 year

PLAN OF EXAMINATION WORK USE IN BIOLOGY

Generalization and application of knowledge about humans and the diversity of organisms

Task C4 (25) includes questions related to the content blocks "System and diversity of the organic world" and "Human body and its health".

SYSTEM AND DIVERSITY OF THE ORGANIC WORLD

Solution of problems in cytology for the application of knowledge in a new situation

Task C6 (26) includes tasks in cytology related to the processes of realization of hereditary information and cell division. The good thing about these tasks is that the questions in them are specific and precise. On the other hand, they are quite complex and require a deep understanding of the processes in question. An important point in solving tasks C5 is an explanation of the actions performed, especially if the task says: "Explain the answer." The presence of explanations allows the examiner to conclude that the students understand the topic, and their absence can lead to the loss of a very important point.

Task C6 (26) is estimated at three points, which are awarded in case of a completely correct solution. Therefore, starting the task, first of all, it is necessary to highlight all the questions. The number of answers must match them, otherwise you can also lose a point.

When solving a number of problems in this section, it is necessary to use the table of the genetic code. The rules for using the table are usually indicated in the assignment, but it is better to learn this in advance. To determine the amino acid encoded by this or that triplet, you must perform the following steps. The first nucleotide of the triplet is found in the left vertical row, the second in the upper horizontal, the third is in the right vertical row. The desired amino acid is located at the intersection of imaginary lines, coming from nucleotides.


TASKS ON QUANTITATIVE RELATIONSHIP IN THE IMPLEMENTATION OF HEREDITARY INFORMATION

be sure to indicate in the explanations following:

• each amino acid is delivered to the ribosomes of one tRNA, therefore, the number of amino acids in the protein is equal to the number of tRNA molecules involved in protein synthesis;

  each amino acid is encoded by three nucleotides (one triplet, or codon), so the number of coding nucleotides is always three times greater, and the number of triplets (codons) is equal to the number of amino acids in the protein;

each tRNA has an anticodon, complementary to the mRNA codon, therefore the number of anticodons, and therefore, in general, tRNA molecules is equal to the number of mRNA codons;

mRNA is complementary to one of the DNA strands, so the number of mRNA nucleotides is equal to the number of DNA nucleotides. The number of triplets, of course, will also be the same.

Problem 1 ... The broadcast involved 75 tRNA molecules. Determine the number of amino acids that make up the synthesized protein, as well as the number of triplets and nucleotides in the gene that encodes this protein.

Decision .

One tRNA molecule delivers one amino acid to the ribosome. The translation involved 75 tRNA molecules, therefore, the synthesized protein contains 75 amino acids.

Each amino acid is encoded by one DNA triplet, therefore the DNA region coding for this protein contains 75 triplets.

Each triplet is three nucleotides, therefore, the indicated DNA region contains 75 x 3 \u003d 225 nucleotides.

Answer:75 amino acids, 75 DNA triplets, 225 DNA nucleotides.

PROBLEMS FOR THE CONSTRUCTION OF mRNA MOLECULE, tRNA ANTI-CODONES AND DETERMINATION OF THE SEQUENCE OF AMINO ACIDS IN PROTEIN

When solving problems of this type, it is necessary to remember andnecessarily indicate in explanations following:

mRNA nucleotides are complementary to DNA nucleotides;

instead of thymine, uracil is recorded in all types of RNA;

mRNA nucleotides are written in a row, without commas, since one molecule is meant;

tRNA anticodons are written separated by commas, since each anticodon belongs to a separate tRNA molecule;

we find amino acids according to the table of the genetic code;

if a table of the genetic code for mRNA is given, thenuse mRNA codons :

amino acids in a protein are written with a hyphen, because it means that they have already combined and formed the primary structure of the protein.

Problem 2. A fragment of the DNA chain has the sequence ACGTTGCCTSAAT. Determine the sequence of mRNA nucleotides, tRNA anticodons and the sequence of amino acids in the synthesized protein.

Decision.



Objective 3.

What chromosomal set is characteristic for the cells of the embryo and endosperm of the seed, leaves of a flowering plant. Explain the result in each case.
Answer:

1) in the cells of the embryo of the seed there is a diploid set of chromosomes - 2n, since the embryo develops from the zygote - a fertilized egg;
2) in the cells of the endosperm of the seed there is a triploid set of chromosomes - 3n, since the ovule (2n) and one sperm (n) are formed by the fusion of two nuclei of the central cell;
3) the cells of the leaves of a flowering plant have a diploid set of chromosomes - 2n, since an adult plant develops from an embryo.

The answer includes all the above elements, does not contain biological errors

The answer includes 2 of the above elements and does not contain biological errors, OR the answer includes 3 of the above elements, but contains non-gross biological errors

The answer includes 1 of the above elements and does not contain biological errors, OR the answer includes 2 of the above elements, but contains non-gross biological errors

Wrong answer

Maximum points

TASK No. 27 (C7)

SOLVING PROBLEMS ON GENETICS ON APPLYING KNOWLEDGE IN A NEW SITUATION

The condition of genetic problems is often voluminous, therefore, first of all, from the condition it is necessary:

highlight the signs in question and enter the appropriate designations;

establish the type of crossing: monohybrid or dihybrid;

to establish the nature of inheritance: complete or incomplete dominance, autosomal or sex-linked, independent (in the case of dihybrid crossing) or linked;

identify all "characters", that is, all individuals indicated in the condition (if there are a large number of such individuals, you can draw up a genealogical scheme for convenience);

establish the genotypes of "characters" and, if necessary, indicate them in the appropriate scheme;

highlight all the questions posed in the condition.

After that, you can start directly solving the problem. To avoid unnecessary losses (meaning points), it is better to accompany all your actions with comments, especially if the problem says “Explain the solution”.

A task. In a family where parents have normal color vision, the son is color blind.

The genes for normal color vision (D) and color blindness (d) are located on the X chromosome.

Determine the genotypes of the parents, the color-blind son, gender and the probability of having children - carriers of the color-blind gene. Make a scheme for solving the problem.

Explanation

1) Genotypes of parents: mother - X DX d, father X DY;

2) the genotype of the son - color blind - X d Y;

3) the probability of birth of carriers of the gene for color blindness (X DX d) – 25%.

The answer includes all the above elements, does not contain biological errors.

The answer includes 1 of the above elements and does not contain biological errors, OR the answer includes 3 of the above elements, but contains non-gross biological errors.

The answer includes 1 of the above elements and does not contain biological errors, OR the answer includes 2 of the above elements, but contains non-gross biological errors.

Wrong answer

Maximum score

List of references

1. FIPI project of control and measuring materials of the exam in 2018.

2. Demos, specifications, codifiers for the exam in 2018. FIPI website.

3. Help about the planned changes in KIM 2018. FIPI website.

4. Site "I will solve the USE": biology, for an expert.

The exam in biology is a selective exam and it will be taken by those who are confident in their knowledge. The Unified State Exam in Biology is considered a difficult subject, since the knowledge accumulated over the years of study is tested.

The USE tasks in biology were selected of various types, for their solution you need confident knowledge of the main topics of the school biology course. Based demos teachers have developed over 10 test items for each topic.

See the topics that need to be studied when completing assignments from FIPI. Each task has its own algorithm of actions that will help in solving problems.

There are no changes in the KIM USE 2020 in biology.

The structure of the tasks for the exam in biology:

• Part 1 - these are tasks from 1 to 21 with a short answer, about 5 minutes are given to complete.

Advice: read the wording of the questions carefully.

• Part 2 - these are tasks from 22 to 28 with a detailed answer, about 10-20 minutes are allotted to complete.

Advice: express your thoughts literally, answer the question in detail and comprehensively, give a definition of biological terms, even if this is not required in the assignments. The answer should have a plan, not write in solid text, but highlight points.

What is required of the student for the exam?

• Ability to work with graphic information (diagrams, graphs, tables) - its analysis and use;
• Multiple choice;
• Establishing compliance;
• Sequencing.

Points for each task in the biology of the exam

In order to get the highest grade in biology, you need to score 58 primary points, which will be translated into one hundred on a scale.

• 1 point - for 1, 2, 3, 6 tasks.
• 2 points - 4, 5, 7-22.
• 3 points - 23-28.

How to Prepare for Biology Test Items

1. Repetition of the theory.
2. Correct allocation of time for each task.
3. Solving practical problems several times.
4. Checking the level of knowledge by solving tests online.

Register, practice and get a high score!

The Unified State Exam in Biology 2018 is an optional exam, it is completely optional. At the same time, this subject takes 5th place after the compulsory Russian language and mathematics, then social studies and physics. 5th place - for biology (it is chosen by about 18% of graduates).

Where does biology come in handy?

Biology is passed in many universities:

1. medical;
2. biological universities;
3. in pedagogy for the specialty "Teacher of Biology";
4. in agricultural;
5. veterinary;
6. at the Faculty of Physical Education;
7. psychological;
8. ecological;
9. at the Faculty of Garden Design;
10. at the Faculty of Biology in technical universities, where biology is studied at the interface with physics.

There are a lot of professions related to biology:

• an engineer who models problems related to human life;
• a doctor who will deal with the treatment of diseases that are possible in the future;
• an ecologist who cares about the health of the whole country. The task of the ecologist is to create conditions in which mankind will drink clean water, breathe clean air;
• psychologist;
• athlete.

These are the people who make a person's life more fulfilling and meaningful and, moreover, prolong this life.

Required documents

The FIPI website contains the following documents required to prepare for the exam in history:

1. Specification (description of the work, the necessary documents are listed, the structure of the exam in biology is reflected, a plan of the KIM version is given).
2. Codifier (list of skills and topics that are tested on the exam in biology).
3. Demo version of the exam in biology (one version of the exam in biology), with which you need to start preparing for the state exam in history.

Features of the structure of the exam in biology

Total 28 tasks
Part 1 Part 2
21 tasks with a short answer 7 tasks with a detailed answer

The time to complete all the work is 3 hours 30 minutes (210 minutes).
The maximum primary score is 59.
The established minimum test score for the exam in biology is 36 points.

How are the key tasks of part 1 of the work arranged?

Task # 1 first appeared in 2017. Each student, preparing for the exam, reads the text, underlines the keywords, then finds the keywords and connections between them. These connections make it possible to build dependency. Thus, the text is structured, it contains connections between concepts. In this task, a fragment from biology is presented, where it is required to show these connections.

Task number 3 is interesting in that ordinary simple tasks have been introduced, where you need to complete a solution knowing biology:

• count the number of chromosomes,
• indicate the number of cells that are formed during various processes, etc.

Task number 4 requires you to choose two statements that correspond to the description of the object that is presented.
Task number 6 for genetics. These are problems for monohybrid crossing, where you need to write a specific number, the ratio of numbers.
Task number 8 on the ratio of examples and phenomena. This is the first example of an assignment. An alternative example of this task is also offered, where a blind drawing (without signatures) is given, and you need to find positions where there are numbers 1 and 2. And only after that, having decided on the position, select the correct answers.
In task number 9, you should find examples from the proposed text that correspond to the concept of "resistance", "microscopicity" and "pathogenicity".
Task number 15 on the knowledge of species properties. In biology, the concept of "species" is the key concept around which all biology is built. Given text. It is necessary to select only those criteria that correspond to the task set in the text.

Task number 20. A new (since 2017), original task that makes it possible to check several very important, key concepts in biology using one example.

• Example 1 tests the understanding of speciation.

Example 2 involves filling in free columns in the table and finding some relationships between structure, object and function.

Task number 21.

• Example 1. Formation of natural science literacy and research skills is possible only when a person is able to work with information presented in various forms. In biology, for example, such information is a table where a scientist, observing, fixes data, writes them down, making a certain calculation. The applicant needs to read what is noted here, as a biologist reads it, who chooses key figures from a stockade of numbers and builds conclusions on this basis. You only need to select 2 statements that strictly correspond to the given conditions.
• Example 2 requires the selection of statements that can be formulated based on the analysis of the histogram. For example, you need to find species, see what they eat, encrypt this species (how to depersonalize) and propose the ratio of food habits of this species. And then it is necessary to evaluate this species based on its eating habits or some other qualities.
• Example 3 is a graphical representation. It tests the ability to read the graph and understand the reasons for the movement of the curve up or down.

A few words about part 2

These are tasks in an open form, where the graduate will have to answer a question and demonstrate in-depth knowledge of the subject. Particular attention should be paid to the language of the response. A student of grade 11 must own a certain conceptual apparatus, biological terms used in answers to tasks.

What will help to effectively help pass the exam in biology?

Of course, the textbooks used in schools. These can be textbooks by different authors that can be combined.

Clear planning of your activities in preparation for the exam in biology 2018.

Deep interest of the student in the study and delivery of the subject with a high score.

You have to be motivated, you have to want to study the subject of biology, and then the result will not be long in coming.

The date of the Unified State Exam in Biology will be known in January 2018.

You can find out about the results of the USE in biology in 2018 in your educational organization or on the official website of the USE.

If the Ministry of Education decides to make some changes to the CMMs of the Unified State Exam in Biology, then you need to be ready for everything, not waste time and start preparing now!

There are a lot of professions related to biology. And if a graduate decided to devote his further life to medicine, psychology, pedagogy, food technology, pharmacology or agriculture, then an exam in biology at the end of secondary school is mandatory for him. What will be USE in biology 2017?

The state exam in biology in 2017 will be different from the exams of previous years. Not many changes have been made, but they are significant.

A new, more streamlined structure of the examination work is proposed. Reduced the number of tasks to 28, compared to 40 in 2016. The maximum number of primary points for all work has been reduced, now it is 59 points, instead of 60 last year. But the amount of time to complete the examination paper has been increased to 210 minutes, instead of 180.

The exam will no longer have single-correct-answer questions. In this regard, the probability of guessing is minimized. After all, before it was possible to connect intuition, pass the threshold and score the minimum allowable number of points. Now intuition is not our assistant, we need knowledge. You will have to prepare carefully, and start as early as possible. But there is good news too. The difficulty of the tasks has not changed, and the time to complete them has increased by 30 minutes.

The exam paper of the USE in biology 2017 contains 28 tasks, consists of two parts, each of which has its own level of complexity and format.

First part of the exam

The first part consists of 21 tasks with a short answer. Moreover, the answers will need to be written in the form of words or phrases, numbers or a sequence of numbers, without spaces and separators.

The first part includes tasks of two levels of difficulty: 10 - basic level and 11 - advanced.

This format is the first innovation and a significant reason for passing the demo version of the exam in biology 2017.

The second innovation in the content of the tasks. The graduate will need:

• analyze information in graphical or tabular form (1 task)
• supplement the missing information in the diagram and table (2 tasks)
• establish the sequence of systematic taxa, biological objects, phenomena, processes (3 tasks)
• solve biological problems in cytology and genetics (2 problems)
• perform tasks with multiple choice (7 tasks) and establish correspondences (6 tasks) with or without a picture

So, 21 tasks of a new type have significant differences and allow you to more accurately assess the knowledge of the material covered, and also require serious preparation.

Second part of the exam (increased difficulty)

The second part of the USE in biology 2017 is focused on graduates with a high level of knowledge in the subject, or rather, on their identification. There will be no changes here. As in 2016, there will be 7 tasks, formed by types of educational activities and in accordance with the topics of the subject. Graduates write the answers to them independently in expanded form. There are also no changes in terms of difficulty: 1 task of the advanced level and 6 of the higher level.

In the second part, the graduate must independently explain and substantiate biological phenomena and processes, be able to analyze, systematize and integrate knowledge, and confirm the theory with practice. And all this should be correctly formulated in a detailed answer.

How is it evaluated

The primary maximum number of points for the state exam in 2017 changed, but not significantly.

For completing 10 tasks of the basic level of difficulty, 17 points are given, for 12 tasks of an advanced level - 24 points, for 6 tasks of a high level - 18. In total - 59 points. for passing the exam in biology will be 36 points.

What you need to know

The exam involves testing the knowledge of the subject in full. And if something is missed, even for a good reason, this fact is not taken into account on the exam. Therefore, it is advisable for a future graduate to start preparing for already in September in order to have time to fill in all the gaps.

Biology knowledge testing will be carried out in the following sections:

• Biology as a Science. Methods of scientific knowledge
• The cell as a biological system
• The organism as a biological system
• System and diversity of the biological world
• The human body and its health
• The evolution of wildlife
• Ecosystems and their inherent patterns

Use this list to test yourself and pull up overlooked topics.

What you need to be able to

On the exam in biology, it is also important to show your skills and abilities to use the knowledge gained. A graduate must correctly apply terminology, identify biological objects not only by description, but also by drawing. When explaining biological processes, a significant advantage will be given to those who use not only the word, but also tables, graphs, diagrams. Solve problems, draw conclusions and apply theoretical knowledge in practice, in everyday life.

Every year FIPI publishes an updated demo version of the Unified State Exam in Biology. The graduate has the opportunity to calmly deal with instructions, assignments, rules of conduct, assessment criteria, practically pass all stages of the exam. Of course, the demo version is not an exact copy of the USE, but, nevertheless, it allows the student to feel calmer and more confident when everything is going on for real.

In preparation for the USE in biology, each graduate must take into account their personal, individual characteristics. Everyone knows their strengths and weaknesses, memory capabilities, performance. Those who have not yet figured out this can turn to their parents and teachers for help. It is worth talking to those who have already taken the exam and get additional information first-hand. In a word, all the methods are good for preparation, the main thing is not to leave everything for May, not to hope for "maybe it will carry over", but to start systematically studying now.

Biology is one of the subjects that the graduate chooses on the exam himself. And if he makes a choice in favor of biology, then this science is to his liking. Therefore, all worries and worries must be left outside the door so as not to interfere. And take with you composure, confidence, remember everything and get the highest score.

Video news, demos

In 2018, more than 133 thousand people took part in the USE in biology, which is slightly more than the number of exam participants in 2017 (111 748) people, 2016 (126 006) and 2015 (122 936). The biology exam is traditionally in demand and is one of the five most popular elective final exams. It is chosen by graduates motivated by biology who enter medical, veterinary, agricultural universities, psychological and biological faculties of universities, academies and institutes of physical culture and sports and a number of other universities.

In 2018, the average test score was 51.4. Its slight decrease compared to last year is primarily due to a decrease in the share of participants in the range of test scores 61–80 (by 2.26%) and an increase in the share of participants in the range of 41–60 (by 3.26%). At the same time, there is a persistent downward trend in the number of participants with results in the range of 81-100. The decrease in the proportion of high-scorers can be explained by a set of measures to improve the quality of verification of detailed answers by experts of the subject commissions of the regions, as well as the inclusion in part 2 of KIM of new plots of a specific, contextual, practice-oriented nature, requiring clear argumentation, and not reproduction of general or particular knowledge on the subject. This allowed for a better differentiation of participants with high test scores.

The minimum test score in 2018, as in previous years, was 36 points, and the primary - 16 points. The share of participants in the USE in biology who did not score the minimum number of points in 2018 was 17.4%. Compared to 2017, the share of participants who scored test scores in the 41-60 range was 40.6% (in 2017 - 37.3%), and in the 61-80 range it was 25.6% (in 2017 - 27.9%).

In 2018, 48 graduates completed all the tasks of the exam and scored 100 points, which amounted to 0.04% of the total number of USE participants. The data obtained testifies, on the one hand, to a sufficiently high level of complexity of the KIM USE model in 2018 and, on the other hand, to the availability of tasks, which is confirmed by the distribution of the primary and test scores of the participants.

More detailed analytical and methodological materials of the USE 2018 are available here.

Our website contains about 5,500 tasks to prepare for the exam in biology in 2018. The general plan of the examination work is presented below.

EXAM PLAN FOR THE USE IN BIOLOGY 2019

Designation of the level of difficulty of the task: B - basic, P - increased, C - high.

The correspondence between the minimum primary scores and the minimum test scores of 2019. Order on amendments to Appendix No. 1 to the order of the Federal Service for Supervision in Education and Science.