Source: Henan Daily
Henan Daily client reporter Feng Junfu Shi Xiaoqi
What are the key contents of the 2021 Henan College Entrance Examination Science Comprehensive Examination? How to answer can I get a high score? Let's take a look at the review and analysis of famous teachers in Henan High School!
Physics: The difficulty of the finale question is significantly increased
Li Meng, a physics teacher at Zhengzhou Foreign Chinese School, believes that this year's physics test questions have increased in difficulty compared with 2020, and the knowledge points examined are basically around the backbone knowledge to proposition, and the score arrangement of each part is more reasonable (41 points in mechanics, 48 points in electromagnetics, 6 points in modern physics, and 15 points in the selection test), the difficulty of the final question has been significantly improved, the analytical reasoning ability and computing ability have higher requirements, other topics are relatively conventional, but there are also highlights and novelties, and the overall view is a very wonderful set of test questions. The specific analysis has the following points:
Multiple choice questions such as the 17th question, examining the half-life of radioactive elements, the question gives the remaining element mass ratio and the relationship between time image, seemingly complex, and even students will try to find the quality ratio and the function relationship of time, but carefully look at the graph analysis, the mass ratio from 2/3 to 1/3 of the time is the half-life, you can directly get the answer, this question can test the flexibility of students' thinking. Another example is question 21, examining the relative sliding problem in the plate model, the clue to solve the problem is hidden in two images, it is necessary to analyze and determine when the plates slide together and when they slide relatively, and then list the equations to deduce the relationship between the relevant physical quantities, which is both comprehensive and deep.
Question 22 examines the calculation of the speed of flat throw motion and requires the calculation of gravitational acceleration; Question 23 measures the electromotive force and internal resistance of the power supply, involving the selection of protection resistance, the analysis of experimental principles, and the calculation of image data and errors. These two questions focus on the basic skills of students, and although they are innovative, they are still routine questions.
Calculation question 25 as the final question, examining the electromagnetic induction and relative sliding problem of the metal rod and the U-shaped frame, the first question is relatively simple, calculating the overall acceleration, speed and amperometric force of the rod can be; but the second question is more complex, involving two objects, multiple processes, inlet magnetic field and outlet magnetic field, acceleration and uniform speed, together motion and relative sliding, the topic conditions are given less, but the equations are more listed, and the calculation amount is relatively large; the third question is based on the second question and then analyze and judge to obtain the final result. This finale question is very comprehensive, and the requirements for students are also very high, which can reflect the selection function of the college entrance examination.
Question 33 examines the ideal gas state change image and the ideal gas state equation respectively, which is still the most core part of the thermal investigation; the first question of the 34 question examines the understanding of the mechanical wave image, which is a classic topic, and the second question of the optical question takes the refractive index of the glass brick as the background, which examines both the law of refraction, the total reflection and the treatment of the angle in geometric optics, and the two questions are of moderate difficulty, both of which are the core examination points of the elective 3-4.
Looking at this year's topics, the elliptical orbit in gravity, the flat throw motion of the experimental question and the measurement of the power supply electromotive force and internal resistance, the electromagnetic induction problem in the final question are all knowledge points that have not been examined in the past 7 years and have appeared this year, while the knowledge points such as static mechanics and alternating current have not been involved this year, which is worthy of the attention of the 2022 candidates.
Biology: The proportion of subjective expression questions has increased
Zhang Changhe, head of the biology teaching and research team of Zhengzhou Foreign Chinese School, believes that the 2021 college entrance examination (volume B) biology test questions are based on the examination of the core literacy and key abilities of biology disciplines. The difficulty of multiple choice questions is basically the same as in previous years, and the difficulty of subjective questions has increased. Pay attention to the basics, enhance flexibility, guide students to reduce rote memorization and "mechanical brushing", attach importance to the cultivation of ability, and give full play to the positive guiding role of college entrance examination propositions. The outstanding features are the increase in the proportion of subjective expression questions, and the examination of the core literacy of scientific inquiry and scientific thinking, especially the experimental design and experimental analysis questions, the score and difficulty have increased.
Question 1 examines the changes in DNA quantity and chromosomal behavior characteristics of animal cells at different stages of mitosis, reflecting the core concept of "cells proliferate by division", and also examining the difference between mitosis and meiosis. Question 3 comprehensively examines the role of water in life activities, and questions 4 and 5 examine the relevant knowledge of neurotransmitters and pneumococcus pneumoniae respectively, which are the core basic knowledge of the textbook. The 31 questions examined the transport route, targeting, physiological role, etc. of hormone regulation, one of the ways of intercellular information exchange, in the form of a table, continuing the form of last year's proposition, reflecting the basic and at the same time conducive to the examination of the core literacy of biology.
The examination of experiments in high school biology is divided into experimental analysis and experimental design in the context of creative problems in textbooks. Both types of questions are reflected in this year's college entrance examination questions. The four options of the second question of the multiple choice question examine the application of two dyes, trypan blue and gentian violet, the role of hydrochloric acid, and the experiment of water absorption loss in plant cells, all of which are textbook content and highlight the basics. While examining the core knowledge of photosynthesis, the 29 questions require students to be able to design experimental schemes based on given conditions, comprehensively test students' ability to explore biological experiments, and highlight innovation. Question 38 calls for a method for screening target strains using antibiotic resistance genes on plasmid vectors, directly pointing to the actual operation of the experiment. The strengthening of the examination of experimental inquiry ability aims to guide biology teaching to return to the essence of the discipline, strengthen experimental teaching, and help the development of core literacy of the discipline.
Question 30 relies on the joint cultivation of large grasshoppers and double-core grasshoppers in the textbook, and at the same time provides students with information "principle of competition exclusion", examines the analysis and prediction of interspecific competition phenomena, and draws conclusions based on experimental results. This question not only creates a problem situation, but also combines experimental analysis. The material of this question is derived from the textbook, the problem design is higher than the textbook, and the students' understanding and application of ecological knowledge and problem-solving ability are comprehensively examined.
The 32 questions are the traditional problem types of the law of free combination of genes, but the difference is that students are required to draw genetic diagrams and solve practical problems by building models, reflecting the application of models and modeling in scientific thinking methods. This topic also examines the core knowledge of genetic laws on the basis of comprehensive examination, focusing on the students' ability to use model methods to study biological phenomena.
Chemistry: "Carbon Peak", "Carbon Neutrality", "Chang'e 5 Probe" into the topic
Yao Weimin, a senior chemistry teacher at Zhengzhou Foreign Chinese School, believes that the 2021 science comprehensive national volume B chemistry test questions are scientifically and reasonablely designed, and the difficulty is moderate. From the overall point of view, the types of test questions are relatively conventional, the content of the examination is rich, and the presentation form is not lacking in novelty. The test questions strengthen the design of scenario-based problems, pay attention to the connection between theory and practice, and the emergence of some hot words such as "carbon peak", "carbon neutrality" and "Chang'e 5 detector" is very close to life and highlights the essential value of chemistry. The test questions also pay attention to the examination of subject ability, focus on the understanding and application of knowledge, such as questions 13 and 28, through the in-depth understanding of charts to reflect the charm of chemistry disciplines, highlight the requirements of chemistry for talent training, and pay attention to the needs of talents in line with the social development of the new era.
From the overall difficulty point of view, compared with previous years, the test questions basically follow the style from easy to difficult, layer by layer, increase the examination of basic knowledge, the last two questions and 28 questions of multiple choice questions through clever design and knowledge integration, taking into account the degree of differentiation.
The multiple-choice questions mainly examine stESE, experimental chemistry basics, ion equation writing, organic chemistry basics, electrochemistry, periodic law of material structure, and ion equilibrium in aqueous solutions. The first 4 questions are very simple, and the last 3 questions are gradually increasing in difficulty. Question 11 grasps the key message "similar to the earth's soil" and it is not difficult to deduce the elemental species. Question 12 as long as the analysis of the specific reaction of the yin and yang poles, it is also easy to get the answer, the 13th question examines the solubility of insoluble substances in the acidic system of the problem, to test the student's ability to read the map, we must first understand the meaning and order of magnitude of the horizontal and vertical coordinates, and then find the starting point and the point of pH = 4 for calculation and reasoning, the answer is still very easy to get.
The 26 and 27 questions are popular question types, which are very similar to the usual practice simulation questions and are not difficult to do. The 28 questions are designed with ICl as the carrier. Emphasis is placed on the calculation and understanding of mechanisms of multi-equilibrium systems. Although the carrier is not very common, but the practice is very conventional, the first (2) ask carefully list the three-paragraph formula, and do not need to calculate the result, the difficulty can be said to be reduced by a grade, the main focus of the first (3) question is to understand the meaning of the horizontal and vertical coordinates and the relationship between K and T, which can be described as in-depth and simple.
The structure and properties of matter examine the atomic structure, coordination compounds, hybridization, boiling point comparison, bond angle judgment principle, etc., which are common test points in ordinary exercises, and the design of the unit cell structure is also very simple, and the difficulty is lower than expected. The organic chemistry basic question gave two pieces of information, the structure is slightly more complicated, the isomer type judgment of the benzene ring ABC three substitutions, the synthesis design is not examined, and the difficulty is moderate. Judging from the comparison of selected questions, it may be that the structure of the questions is more conducive to students' scores.
This article is from [Henan Daily Network] and only represents the author's views. The National Party Media Information Public Platform provides information release and dissemination services.