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 share 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 by 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 the 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 USE participants 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 range 41-60 was 40.6% (in 2017 - 37.3%), and in the range 61-80 it was 25.6% (in 2017 - 27.9%).

In 2018, 48 graduates completed all the tasks of the examination 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 5500 tasks to prepare for the Unified State Exam in Biology in 2018. The general outline of the examination work is presented below.

THE EXAMINATION PLAN OF THE USE IN BIOLOGY 2019

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

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.

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 THE EXAMINATION WORK OF THE 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 correspond to 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 a particular 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 row., 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 RELATIONSHIPS 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), therefore, 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.

Solution .

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 = 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.

Solution.



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 a 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 GENETIC PROBLEMS FOR KNOWLEDGE APPLICATION 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;

set the type of crossing: monohybrid or dihybrid;

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);

to 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 proceed to the direct solution of 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”.

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 likelihood 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 dY;

3) the probability of the birth of carriers of the color blindness gene (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

Bibliography

1. FIPI project of control and measuring materials of the Unified State Exam in 2018.

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

3.Information about the planned changes in the CMM 2018. FIPI website.

4. Site "I will solve the Unified State Exam": 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, as the knowledge accumulated over the years of study is tested.

The USE tasks in biology were selected of various types; to solve them, 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.

For topics that need to be studied when completing assignments, see from FIPI. For each task, its own algorithm of actions is prescribed, which 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, approximately 10-20 minutes are allotted to complete.

Advice: express your thoughts in literature, answer the question in detail and comprehensively, define 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 a 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 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, study and get a high score!

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

M .: 2017 .-- 128 p.

The proposed manual provides a description of the main types of tasks with a detailed answer to Part 2, used in the exam, provides the answers of graduates and comments on their assessment. Particular attention is paid to the analysis of tasks that caused the greatest difficulties, as well as typical mistakes made by graduates in different years. For training and self-preparation for the Unified State Exam, tasks with a detailed answer of various levels of complexity for all meaningful blocks are offered (34 - 40). At the end of the manual, there are samples of answers with assessment criteria. The manual is addressed, first of all, to students and applicants who have to take the exam in biology; it will also be of interest to school teachers, methodologists and parents.

Format: pdf

The size: 2.8 Mb

Watch, download:drive.google

CONTENT
INTRODUCTION 4
I. BASIC TYPES OF JOBS OF PART 2 WITH A FREE EXTENDED ANSWER AND THE METHOD OF THEIR ESTIMATION 7
II. TYPICAL GRADUATES ERRORS IDENTIFIED DURING THE ANALYSIS OF JOBS WITH A FREE EXPLANATORY ANSWER (PART 2) 20
III. JOBS WITH AN EXTENDED ANSWER FOR INDEPENDENT SOLUTION 45
IV. ANSWERS TO TASKS WITH AN EXTENDED ANSWER FOR INDEPENDENT SOLUTION 63

Of great importance for the certification of school graduates and their selection to universities using the control measuring materials of the exam are tasks with a free answer. Unlike tasks with a choice of answer, when performing tasks with a free answer, a hint or guessing the correct answer is excluded. Students must independently formulate the answer to the question posed. Tasks of this type are of great importance for identifying the level of formation among graduates not only of knowledge, but also of educational skills, for differentiating students by their level of training and selection to higher educational institutions of a biological profile. The inclusion of tasks with a detailed answer in the examination work makes it possible not only to assess the educational achievements of the examinees, the depth of their knowledge, but also to reveal the logic of their reasoning. These tasks allow you to get objective results when conducting the exam.
When performing tasks with a detailed answer, the degree of mastery by students of various types of educational activities, certain skills is controlled: to characterize, recognize, determine, compare, explain and compare biological objects, processes and phenomena, establish cause-and-effect relationships, generalize, substantiate, draw conclusions, apply theoretical knowledge for solving biological problems, thinking logically. When completing these tasks, the examinees have the opportunity to fully, deeply and competently express their thoughts, demonstrate the depth of knowledge in biology.