How to design an experiment report for high school biology students
To design a high school biology experiment report, you can follow the following steps: ** 1. Confirm the purpose of the experiment ** 1. ** Confirming experiment **: The purpose of the experiment is to find information similar to "verify..." in the question. 2. ** Investigative experiment **: To analyze the independent variable and dependent variable in the experiment. The purpose of the experiment can generally be written as "explore the influence of the independent variable on the dependent variable","explore the relationship between the independent variable and the dependent variable", or "explore the role of the independent variable". ** 2. Propose an experimental hypothesis ** make conjectures based on the subject or purpose of one's research. Since this kind of question may be open, the hypothesis must have a theoretical basis. It can be presented in the form of "if... phenomenon, then... conclusion". ** 3. Confirm the experimental principle ** Experimental principles were the theoretical basis for designing experiments. One needed to master the selection basis of various reagents and the corresponding physiological processes in biology textbooks to determine it. ** 4. Conception of experimental ideas ** There was no need for detailed operation steps. He only gave a rough experimental design process, such as using a certain method to deal with a certain material and then observing the effect on a certain aspect. ** 5. Plan the experiment steps ** 1. ** Commonality Treatment Experiment Materials ** - [Material Selection: Obtain materials reasonably according to the type of experimental materials.] For plants, choose the same kind of plants (or the same parts of the same kind of plants) with the same growth and similar size; for animals, choose healthy individuals with similar physiological conditions; and for solutions, take the same amount of a solution. - [Group and Numbering: Divide the materials into several groups, which can be numbered A, B, C, or A, B, C, etc.] 2. ** Single variable principle, control each group of materials ** - Control group: No experimental variables were applied. - Experimental group: Experimental variables applied. At the same time, unrelated variables must be controlled to ensure that other conditions were the same and appropriate, and the reagents were equal and appropriate. 3. ** Same conditions, same cultivation time ** 4. ** Observe and record the experimental results **: After the experimental subject is placed in the same and suitable environment for cultivation for a period of time, observe (such as color changes, settling reactions, changes in shape, structure, physiological characteristics, etc.) or measure (growth and development speed, biochemical reaction speed, etc.) related indicators, and record the data. ** 6. Analysis of the experiment results and conclusion ** 1. ** Confirming experiment **: The conclusion is usually in the title, and it is followed by the words "verify...","prove...", etc. 2. ** Investigative experiment **: The results and conclusions are not unique. You need to list all possible results and describe it as "If a certain experimental result appears, it indicates a certain experimental conclusion". Read more exciting novels for free
High School Biology Tadpole Experiment Report
The following is an example of a high school biology tadpole experiment report: ** 1. Purpose of the experiment ** To observe and study the growth and transformation process of tadpoles. ** 2. Experimental Materials ** tadpoles, water tanks, water, spirularia, etc. ** 3. Experimental Steps ** 1. experimental preparation - Collect fresh tadpoles, prepare a water tank, put enough water in the water tank, and add an appropriate amount of spirularia as food for the tadpoles. 2. experimental observation - He gently placed the tadpoles into the water tank and began to observe their living conditions. - In the early days, tadpoles were observed to have curved bodies and undeveloped limbs. They swam by wagging their tails and used spirinoceros as food to shuttle back and forth in the water. Sometimes, they would stop at the edge or bottom of the sink. - As time passed, the tadpoles began to develop four limbs. Their tails gradually shrank, and their limbs gradually became slender. At the same time, they became more active, and their swimming speed and strength increased. - During the growth of the tadpoles, it was also observed that the black pupils gradually became lighter, and the color of the body became more transparent, which may be related to the nutrients contained in the spirularia. - Finally, the limbs of the tadpoles fully developed, and their tails almost completely disappeared, turning into frogs (but smaller). Some of the tadpoles began to come ashore to breathe air, indicating that they were gradually adapting to the land environment. ** 4. Experiment conclusion ** Through this experiment, he had a deep understanding of the growth and transformation process of tadpoles. Tadpoles had a tail, black pupils, relied on water to live, and their limbs were not developed. After a period of growth and development, they gradually developed limbs, their tails degenerated, their body color became transparent, and their black pupils became lighter. They began to adapt to the land environment and finally transformed into a frog-like form. In addition, there were also related tadpole experiments to explore the effect of the hormone on the growth and development of tadpoles. 1. experimental preparation - Two plastic water tanks were filled with an equal amount of tap water, and they were set up as groups A and B. - In the subsequent experimental steps, the two groups of tadpoles might be treated differently (for example, group A was added with hormone, group B was used as a control, etc.), and then the differences in the growth and development of the two groups of tadpoles, including the differences in growth rate and morphous changes, could be observed to draw conclusions about the effects of hormone on the growth and development of tadpoles. The above contents can be adjusted and supplemented according to the actual experimental situation. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
High school biology experiment DNA
High school biology experiments mainly involved observing the distribution of DNA and DNA in cells, as well as the rough extraction and identification of DNA. In the experiment to observe the distribution of DNA and DNA in cells: - The principle was to use the methylate-green pyronine dye solution to dye DNA and R A. The methylate-green dye solution made the DNA appear green, and the pyronine dye solution made the R A appear red. From this, it could be observed that DNA was mainly distributed in the nucleus (dyed green), and R A was mainly distributed in the plasma (dyed red). - For the selection of materials, oral cells or onion inner skin cells (colorless) were often used to avoid color interference. - The effects of the reagents in the experiment: 0.9% NaCl-solution (physiological salt solution) could maintain the normal form of oral cells;8% sulfuric acid could change the cell membrane's penetrability, accelerate the dye to enter the cells, and also separate the DNA and protein in the embryos, which was beneficial to dyeing; the methyla-green pyronine dye solution needed to be mixed and used immediately. In the DNA extraction and identification experiment: - The principle was as follows: - DNA and protein had different degrees of dissolution in different concentration of NaCl-solutions. - DNA was not dissolved in alcohol, but some of the protein in the cells was dissolved in alcohol, which could be used to further separate DNA and protein. - The DNA turned blue after being heated in a boiling water bath. - Operation process: - The materials were selected from biological tissues with relatively high DNA content. Take chicken blood as an example. When breaking the cells, the chicken blood cells were mixed with distilled water, stirred with a glass rod, and then filtered with gauze to collect the filtered liquid. - The impurities were removed by controlling the concentration of the NaCl-solution to remove the impurities. - The extraction of DNA was to filter the processed solution and add a cooled 95% alcohol solution with the same volume as the filtered solution. - The identification of DNA was to add the diamidinium reagent to the solution containing DNA. After mixing it evenly, the test tube was placed in boiling water and heated for 5 minutes. If the solution turned blue, it proved the existence of DNA. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
High school biology experiment technology summary and reflection teaching plan design
The following is a lesson plan for a summary and reflection of high school biology experimental techniques: ** 1. Teaching objectives ** 1. knowledge objectives - Students were asked to review the main experimental techniques involved in high school biological experiments, including the experimental steps, experimental principles, and so on. - Understand the importance of different experimental techniques in biological science research and practical applications. 2. ability objective - Through the summary, the students could improve their ability to summarize and integrate biological experimental techniques. - Cultivate the students 'ability to reflect on the problems, mistakes, and improvement methods encountered during the experiment. 3. emotion goal - To stimulate students 'interest in biological experiments and cultivate a rigorous scientific attitude. ** 2. Important and Difficult Points in Teaching ** 1. ** Main point ** - Comprehensively sort out the common techniques in high school biology experiments, such as the use of a microscope, material extraction, and identification. - Guide the students to summarize the experimental principles, operation steps, and experimental results. 2. ** Difficulty ** - Students were encouraged to reflect on the mistakes in the experiment process and propose effective improvement measures. - It enabled students to establish connections between different experimental techniques and form a complete knowledge system. ** 3. Teaching Method ** Lecturing, discussion, and group cooperation ** 4. Teaching process ** 1. Course Introduction (5 minutes) - Ask the students to recall the general content of the high school biology experiment by asking questions. For example,"Students, we have done a lot of experiments in the high school biology course. Can you first name a few experiments that are more impressive?" - According to the students 'answers, they briefly mentioned the experimental techniques used in these experiments, leading to the theme of this lesson-- 2. Experimental Techniques (20 minutes) - The students were divided into small groups (4 - 5 people per group) and assigned tasks. Each group was responsible for concluding a type of biological experimental technology. For example, the first group was responsible for microscope-related experimental technology (cell observation experiment, etc.), the second group was responsible for material extraction and identification experimental technology (such as the extraction of choroplasts, fat identification, etc.), and the third group was responsible for exploratory experimental technology (such as exploring the factors that affect the activity of the reagent). - Each group discussed and sorted out the relevant content of this kind of experimental technology, including the experimental principle, operation steps, key points, and the way to present the experimental results. - Each group sent a representative to report, and the teacher made a brief note on the blackboard to form an overall high school biology experimental technical framework. 3. Experiment Reflection (20 minutes) - The teacher guided the students to reflect on the experimental techniques reported by each group. For example, in the experiment on the use of the microscope, he asked,"What difficulties have you encountered when using the microscope to observe the cell structure? How was it resolved? If you do this experiment again, what aspects will you improve on?" - The students were asked to discuss again in small groups, focusing on the mistakes in the experimental process, areas that could be improved, and the limitations of these experimental techniques in practical applications. - Each group shared the results of the discussion, and the teachers commented and supplemented, emphasizing the importance of experimental reflection to improve experimental skills and scientific literacy. 4. Overall Knowledge Integration (10 minutes) - According to the previous records and the results of the students 'discussion, the teachers integrated the overall knowledge of the high school biology experimental techniques and summarized the connections and commonalities between different experimental techniques. For example, many experiments involved the use of scientific methods such as the control principle and the control variable method. - Students should be guided to understand the biological experimental technology system from a macro perspective. Students should understand that different experimental techniques are used to explore various phenomena and laws in the biological sciences. 5. Class summary (5 minutes) - The teacher summarized the lesson, emphasizing the significance of the summary and reflection of high school biological experimental techniques for students 'biological learning and scientific inquiry ability. - Arrange homework: Ask students to choose a biological experiment that they are most interested in and write a detailed summary and reflection report of the experimental techniques, including a detailed description of the experimental techniques, their gains and shortcomings in the experiment, and ideas for future experiments. ** 5. Teaching Resources ** Multi-media equipment (used to display relevant experimental pictures, videos, and other auxiliary teaching materials), blackboards, chalk, etc. ** 6. Teaching Evaluation ** 1. By observing the students 'performance in group discussions and reports, the students' mastery of biological experimental techniques and their ability to summarize were evaluated. 2. According to the completion of the students 'homework after class, the depth of the students' reflection on the experiment and the overall understanding of the experimental techniques were judged. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
How to improve the accuracy of biology experiment questions for junior high school students
If junior high school students wanted to improve the accuracy of biology experiment questions, they could start from the following aspects: ** 1. Basic Knowledge ** 1. A firm grasp of the basic knowledge of biology, a deep understanding and flexible application of the basic principles, concepts, and laws of biology were the cornerstone of answering biological experiment questions. 2. In-depth understanding of the design ideas of the teaching materials, including carefully analyzing the experiments in the teaching materials, clearly understanding the principles and objectives of each experiment, grasping the basis for the selection of materials, experimental methods, and steps. At the same time, it would analyze the experimental conditions, processes, phenomena, and results in depth. It would be able to describe the principles, purposes, steps, phenomena, results predictions, and conclusions of classic experiments, thus building a framework for experimental design questions. ** 2. Thinking ability ** 1. He learned how to train in variations of known experiments and develop his thinking of seeking differences. Because many experiments could choose different materials, design different steps, or draw the same conclusion from different results, this kind of training could help improve the comprehensive ability and scientific literacy of the experiment. 2. The experiment was designed to simulate the classic experiment in the textbook. The classic experimental principles and methods in the textbooks were rigorous and scientific. If one often carried out such targeted training, one could master the general rules of experimental design and improve their experimental design ability and skills. ** 3. Skill in answering questions ** 1. When solving a problem, you must find the key words and make sure the proposition is directed to avoid answering the question. 2. He analyzed the intention of the proposition, determined the scope of knowledge to be tested, eliminated interfering information, and prevented thinking. 3. According to the restrictions in the question, the scope of the answer was reduced to improve the accuracy of the answer. 4. Use the professional terms in the textbook to answer questions to ensure that the words used are scientific and standardized. 5. He had to consider everything and answer all the key points to ensure the completeness of the answer. At the same time, he had to sort out the key points of the answer to improve the conciseness of the narration. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Simulation Junior High School Biology Experiment
The following was some content related to the junior high school biological simulation experiment: ** I. Virtual simulation experiment between Hengdian and universities ** 1. ** Specialties ** - Build a completely virtual experimental environment based on real-life data collection. It could bring about an immersive and interacting teaching experience. The images were highly simulated and could present mechanisms that were difficult to observe. - It avoided the problems of high investment, high risk, difficulty in grasping, and difficulty in observation in biological experiments. - Based on the concept of MOOL (large-scale online open laboratory), the addition of interaction and operational experimental content on the basis of paying attention to the content of the course was the development of MOOCs, focusing on cultivating students 'practical, investigative, and innovative abilities. - With the students as the center, the difficulty of the course was gradual and focused on all-round development. There was a more scientific, comprehensive, and systematic evaluation system, which made it easy for teachers to teach according to their aptitude, control the teaching progress, adjust the teaching strategy, and fully implement the concept of opening and sharing. 2. ** Meaning of application ** - It was a new tool to change education by bringing revolutionary educational innovation to college biology courses. ** 2. Ju Dao Junior High School Biology VR 3D Virtual Simulation Laboratory (demo version)** 1. ** Specialties ** - It is guided by the core accomplishments of the subject, scientific, inquiring, and open. The equipment had been modeled with high precision and could be displayed in all directions and angles. - Relying on a powerful intelligent algorithm engine and 3D engine, it guarantees the accuracy of experimental data and the high accuracy of experimental phenomena. It had a high degree of freedom of interaction, timely and clear operation prompts and error prompts, and simple and efficient operation. - It could restore the real experiment process to the greatest extent and complete scenes that were difficult to achieve in traditional laboratories, such as microscopic, macro, and dangerous experiments. - It meets PC mouse, keyboard, and touch screen operation, has VR/3D immersive operation mode, and supports mainstream VR devices to make knowledge more intuitive and interesting. It is suitable for normal teaching and innovative education modes. 2. ** Software module ** - It was composed of a synchronized experiment module, a micro-eye module, a human body exploration module, an evolutionary tree module, and an object library module. 3. ** Synchronization experiment module content ** - It closely followed the curriculum standards and met the teaching needs. It covered six major knowledge points, including biology and cells, and people in the biosphere. The experiment catalog included student group experiments, teacher demonstration experiments, and important knowledge points. Each experiment had a detailed introduction to meet the needs of preparation and review. It can visualize the abstract and virtual phenomena in the experiment, which is convenient for students to understand. 4. ** Micro-Eye Myriad module content ** - There were nearly 100 high-definition microscope images, covering zoology, botany, biology, and microbiology. It supported the free switching of 4×, 10×, and 40×. It was suitable for teachers 'teaching demonstration and students' independent observation. Different observation methods were provided, and the image resolution could be adjusted to enlarge and observe. ** 3. Other junior high school biology simulation experiments ** 1. There were also simulation experiments for the production and use of animal models. The purpose was to master the method of making biological models, learn how to use materials to make biological models, understand the development process and current situation of bionics, and cultivate interest in life sciences. The principle was to use animal models to simulate animals and plants in the real environment to learn biological knowledge. Materials and tools such as animal bones or muscle tissue, plastic tubes, and so on needed to be prepared. 2. There is a junior high school biological simulation experiment software. The hardware requirements are: operating system: Windows7 or above, memory: 2GB or above, display resolution: 1024*768 or above, CPU: Intel Core i3 or above. You can download the installation package for free at Guanfang Global Information Station by registering an account. After installing it according to the installation wizard, double-click the desktop icon to open the software. 3. The Judao Junior High School Physics and Chemistry Experimental Evaluation System was based on VR/3D virtual simulation technology to provide a virtual experimental environment and a high sense of immersion. It had intelligent diagnosis and analysis technology to automatically score, diagnose and analyze, and meet the needs of students to practice experimental operations anytime and anywhere. It could be used for schools to organize mock exams and teacher tests. The school could grasp the details of students 'experimental scores and video data and explain the error-prone points. It could also be integrated into provincial and municipal examination platforms to create a test question library for practice or pre-examination simulation. It was convenient for the education department to evaluate the teaching quality and analyze the learning situation. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
The Writing Method of High School Biology Experiment
High school biology experiments usually included the following important parts: ** 1. Experiment Title ** The main content of the experiment should be clarified, and the core content of the experiment should be summarized concisely, such as "exploring the effect of temperature on the activity of the enzyme". ** 2. Experiment Purpose ** 1. ** Knowledge target ** - Explain the biological knowledge concepts to be understood or verified through experiments, such as "understanding the principle of the effect of temperature on the activity of an enzyme". 2. ** Ability Target ** - He explained the skills to be trained during the experiment, such as "mastering the application of the variable control method in the experiment, learning to use specific experimental instruments for measurement and observation", etc. ** 3. Experiment Principle ** 1. ** Biological Principles ** - Explain the basic biological principles that the experiment is based on. For example, in the experiment of "Observing the plasmatic separation and recovery of plant cells", the principle is that the protoplasma layer of plant cells is equivalent to a semi-transparent membrane. When the concentration of cell fluid is lower than the concentration of the external solution, the cell loses water and plasmatic separation occurs. When the concentration of cell fluid is higher than the concentration of the external solution, the cell absorbs water and plasmatic separation occurs. 2. ** Principle of related technology (if any)** - If special technical means were involved, such as dyeing techniques, the principle must be explained. For example, in the experiment of "Observing the distribution of DNA and DNA in cells", the affinity of methy-green and pyro red stains for DNA and DNA was different. methy-green made DNA appear green, and pyro red made DNA appear red. ** 4. Experimental Materials and Tools ** 1. ** Experiment Materials ** - List the biological materials used, including the types and parts of the organisms. For example, in the experiment of "Observing the Mitosis of Plant Cell", the materials were onion root tips (onions, garlic). 2. ** Experiment Tools ** - Write down in detail the required instruments, reagents, etc., such as microscope, slide, cover glass, disintegration solution, gentian violet dye solution, etc., and indicate the necessary information such as the concentration of the reagent. ** 5. Experimental Steps ** 1. ** Preparing Stage ** - This included the pre-treatment of the experimental materials, such as the cultivation of onion root tips in "Observing the mitosis of plant cells"(3 - 4 days before the experiment, place the onions on a wide-mouthed bottle filled with water, the bottom of which is in contact with the water. The device is placed in a warm place, and pay attention to changing the water frequently. The purpose is to prevent the roots from rotting. Wait until the roots grow to 5 cm). 2. ** Operation procedure ** - Each step of the operation was described in detail in order, including the actions of the operation, the amount of equipment or reagents used, etc. For example, in the experiment of "making and observing the temporary mounting of the onion scale leaf inner skin cells", the rubbing was done.(Wipe the slide clean with a clean gauze, then take a cover glass and wipe it clean. Put the cover glass on one end of the slide for later use.)(Drip 1 - 2 drops of water in the center of the slide with a dropper)(Take a piece of onion scale leaf, cut a small square about 0.5 cm with a blade on the inner skin, and then tear a small piece of transparent film with tweezers)(Dip the peeled inner skin into the water droplets on the glass slide and flatten it with tweezers), cover (use tweezers to pick up the cover glass so that one side of it touches the water droplets on the glass slide first, then slowly put it down and cover it on the material to be observed), dye (then drop a drop of the solution of the solution of 3. ** Points to note ** - During or after each step, the points that needed special attention were indicated. For example, when using a microscope for observation, it was necessary to pay attention to the low power microscope before the high power microscope; when making temporary mounting, it was necessary to keep the experimental materials moist. ** 6. Experiment result ** 1. ** Anticipated result ** - According to the theory and purpose of the experiment, he could deduce the possible results. For example, in the experiment of "exploring the effect of temperature on the activity of an enzyme", if the temperature was within a suitable range, the activity of the enzyme would be higher and the reaction speed would be faster; if the temperature was too high or too low, the activity of the enzyme would decrease, and the reaction speed would slow down or even stop. 2. ** Real-world result (if the experiment has been completed)** - An objective description of the phenomena observed or the data measured during the experiment can be presented in the form of tables, charts (such as bar charts, line charts, etc.), or text. ** 7. Experiment conclusion ** 1. ** Analysis of the results ** - To analyze the experimental results and explain the reasons for the results. For example, in the experiment of "Observation of plasmatic wall separation and recovery of plant cells", the cell structure and physiological mechanism of plasmatic wall separation or recovery were analyzed. 2. ** Come to a conclusion ** - According to the analysis of the results, the final conclusion of the experiment should be summarized. The conclusion should be closely related to the purpose of the experiment, such as "temperature has a significant effect on the activity of the protein. Within a certain range, the activity of the protein increases with the increase of temperature. After exceeding the optimal temperature, the activity of the protein decreases with the increase of temperature." ** 8. Analysis of errors (if any)** 1. ** Source of error ** - Find out the factors that may cause the experimental results to be inconsistent with expectations, such as the accuracy of the experimental instrument, the individual differences in the experimental materials, and human errors in the operation process (such as errors in measuring reagents, etc.). 2. ** Modification measures ** - In view of the source of error, the improvement methods were proposed, such as improving the accuracy of the instrument, increasing the number of experimental samples to reduce the influence of individual differences, and regulating the operation process. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
High school biology compulsory one experiment list
The following are some of the experiments required for high school biology: 1. * * Observe the distribution of DNA and DNA in cells ** - * * Principle **: DNA is green, while DNA is red. Eukaryotic DNA was mainly distributed in the nucleus, while mitochondria and plastids contained a small amount of DNA. - * * Material selection **: oral cells or onion inner skin cells (colorless to prevent color interference). - * * Reagents and effects **: 0.9% NaCl-solution to maintain the normal cell form; 8% sulfuric acid to change the cell membrane penetration, so that DNA and protein can be separated for staining; mixed with the methyla-green pyronine dye solution. - * * Note **: Wash the cells slowly to prevent them from being washed away. - * * Results **: The nucleus is green, and the plasma is red. 2. * * Material Identification ** - * * Detection of reducing sugar ** - * * Principle **: reducing sugar + Fehling reagent → brick-red precipitations. - * * Material selection **: White or almost white materials with high reducing sugar content, such as apples, pears, and white radishes. Green leaves, watermelons, blood, potatoes (containing starch), sugar cane, and beets (containing sugar) cannot be used. - * * Reagents **: Ferlin's Reagents (Solution A: 0.1g/ml of NaOx solution, Solution B: 0.05g/ml of CuSO4 solution). - * * Steps **: Take 2 ml of sample solution and put it in a test tube. Add 1 ml of Fehling's reagent (mix the solution A and B evenly before adding). Heat it in a water bath for about 2 minutes and observe the color change (white → light blue → brick red). - * * Simulated urine sugar test **: Take the urine of normal people and patients with diabetes, and use Fehling's reagent (heated in a water bath), Bancroft's reagent, or urine sugar test paper to test. The urine of patients with diabetes contains reducing sugar and has brick-red deposits, while the urine of normal people does not contain reducing sugar or deposits. - * * Fat Detection ** - * * Principle **: Fat + Sultan III → orange; Fat + Sultan IV → red. - [Material Selection: Tissues with high fat content, such as peanut cotyledon.] - * * Steps **: Make the slices (the thinner the better). Drop 2 - 3 drops of Su Dan III dye solution on the peanut slices for 2 - 3 minutes, then suck off the dye solution. Drop 50% alcohol to wash off the floating color, then suck off the excess alcohol. Drop 1 - 2 drops of water on the slices, cover them with a cover glass, and perform microscopic examination (observe the fat particles dyed orange under low to high magnification). - * * Detection of protein ** - * * Principle **: protein + biuret reagent → purple reaction. - * * Reagents **: Biuret reagent (solution A: 0.1 g/ml of a solution of NaOx, solution B: 0.01 g/ml of a solution of CuSO4). - * * Steps **: Add 2 ml of sample solution to the test tube, add 1 ml of biuret reagent A, and shake it up. Add 4 drops of solution B, shake it up, and observe the color change. 3. * * Observing the flow of the plastids and the plasma ** - * * Materials **: Fresh moss leaves, black algae leaves or spinach leaves, and temporary slices of oral cells. - * * Principle **: Under the microscope, the plastids are green, spherical or oval. 4. [Observing a variety of cells with a microscope (compulsory one, P7)] <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
How to write the purpose of an experiment in high school biology
1. Confirming experiment: Find key information such as " verify..." from the question. The purpose of the experiment is usually written as " explore the influence of the independent variable on the dependent variable,"" explore the relationship between the independent variable and the dependent variable," or " explore the role of the independent variable," etc. 2. Investigative experiment: First, analyze the independent variable and dependent variable of the experiment. The purpose of the experiment is generally expressed as " explore the influence of the independent variable on the dependent variable "," explore the relationship between the independent variable and the dependent variable ", or " explore the role of the independent variable ". <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Senior High School Biology Experiment on Photosynthesis and Breathing
The following are some of the experimental designs for photosynthesizing breathing in high school biology: ** 1. Using droplet movement to measure photosynthesis and respiratory rate ** 1. ** Device Setting ** - For the measurement of breathing rate: - Use a sealed container to place plant materials (such as leaves or germinated seeds). The container was filled with a solution that could absorb carbon dioxide (such as a solution of NaOx). - The container was connected to a graduated glass tube (such as a U-shaped tube) with a drop of colored liquid in it. - "Principle: Under dark conditions (ensure that only breathing is carried out), the plant absorbs oxygen and releases carbon dioxide. As carbon dioxide is absorbed by the solution, the gas pressure in the container will decrease, and the droplets will move towards the container. The distance (or volume) that the droplet moved in a unit of time could represent the breathing rate (commonly used to measure the breathing rate by the amount of oxygen absorbed in a unit of time). - As for the measurement of the net photosynthesis rate: - A similar device, but the container is filled with a substance that can provide a stable concentration of carbon dioxide (such as a solution of NaHCO3, which can decompose to produce carbon dioxide). - When the device was placed under light, the plants would undergo photosynthesis and breathing. The oxygen produced by photosynthesis would increase the pressure in the container, and the droplets would move away from the container. The distance (or volume) that the droplets moved in a unit of time could represent the net photosynthesis rate (usually expressed as the amount of oxygen released or the amount of carbon dioxide absorbed). - The calculation of the true photosynthesis rate: true photosynthesis rate = net photosynthesis rate + respiratory rate. 2. ** Experiment Notes ** - Variant Control: - Light intensity: If you want to explore the effect of light intensity on the rate of photosynthesis, you can use different power bulbs or change the distance between the bulb and the plant to control the light intensity. - [Temperatures: Different thermostats can be used to control the experiment temperature.] - [Concentration of carbon dioxide: For example, carbon dioxide buffer solutions of different concentration can be used for adjustment.] - Principle of comparison: You can't experiment with just one set of equipment by gradually changing its conditions. Instead, you should use a series of equipment to compare with each other. ** 2. Black-and-white bottle method to measure the photosynthesis and respiratory rate ** 1. ** Operation method ** - Prepare several sets of black and white bottles. The black bottle was wrapped in a black material (so that it was in a dark environment), while the white bottle was normally transparent. - Put an equal amount of plants (aquatic plants such as algae are more convenient) and an equal amount of water in each bottle. 2. ** Principle ** - The plant in the black bottle only breathed, and the measured value was the intensity of the breathing (such as the reduction of oxygen or the increase of carbon dioxide). - The plants in the white bottle were photosynthesizing and breathing under light, and the measured value was the net photosynthesis intensity (such as the increase in oxygen or the decrease in carbon dioxide). - Combining the data of the black bottle and the white bottle, the true photosynthesis intensity value could be obtained (true photosynthesis rate = net photosynthesis rate + respiratory rate. The net photosynthesis rate here is the white bottle data, and the respiratory rate is the black bottle data). ** 3. Half-leaf method to measure the photosynthesis and respiratory rate (half-leaf weighing method)** 1. ** Operation process ** - Choose the leaves of the plant and cover half of them from the light (such as covering them with black paper), while the other half is under normal light. - After a period of time (usually a few hours to a day, depending on the plant species and experimental conditions), the leaves were taken down, and a hole cutter was used to punch out leaf discs of the same area on the light-blocking part and the non-light-blocking part of the leaves. - The leaf discs were dried to a constant weight and weighed. 2. ** Principle ** - The light-blocking part was only used for breathing, and the weight reduction was due to the consumption of organic matter by breathing. - The unshielded part underwent photosynthesis and respiration, and its weight change was the difference between the organic matter produced by photosynthesis and the organic matter consumed by respiration. By comparing the weight changes of the two parts of the leaf discs, the total amount of organic matter produced by photosynthesis could be calculated, and thus the photosynthesis rate (commonly used to measure the photosynthesis rate of field crops) could be obtained. ** IV. Studying the influencing factors of photosynthesis and respiratory rate with the gradient-based method ** 1. ** Device Setting ** - Prepare a series of devices with the same plants in each device. - Different conditions such as light intensity, temperature, or carbon dioxide concentration were set in different devices. 2. ** Purpose * - The effects of light intensity, temperature, or carbon dioxide concentration on the intensity of photosynthesis could be investigated. For example, by setting different light intensity (such as using different power bulbs or changing the distance between the bulb and the plant to set low, medium, and high light intensity), the plant's photosynthesis rate under each light intensity can be measured (the change in oxygen or carbon dioxide can be measured by the droplet movement method mentioned above or other methods), and the relationship curve between light intensity and photosynthesis rate can be obtained. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
The easiest biology experiment questions in junior high school
Junior high school biology test questions included exploring the effect of alcohol on the heart rate of water fleas and the effect of smoking on the health of mice. In the experiment of the effect of alcohol on the heart rate of the water fleas, it was necessary to clarify that the experimental variable was the alcohol concentration. It could be assumed that the alcohol concentration had an effect on the heart rate of the water fleas. In order to highlight the effect of alcohol, a control group with only water and no alcohol should be set up. The experimental results showed that as the alcohol volume fraction increased, the heart rate of the water fleas gradually decreased until they died. In the experiment to explore the effects of smoking on health, if the number of mice was too small, the experimental results would be highly accidental and lacked scientific persuasion. After improvement, the conclusion that smoking was harmful to health could be drawn by comparing the normal group A mice with the group B mice with symptoms such as bloodshot, red and swollen eyes, abnormal activity, and finally spasm and shock. There were also experiments related to the fermentation of microorganisms, such as the experiment of decomposing glucose by yeast to produce alcohol and carbon dioxide in the absence of oxygen during brewing. Yeast was needed in the process of producing fuel alcohol from sugar liquid to alcohol using corn stalks. In addition, experiments related to the formation of vision may also be test points. For example, the order of light entering the eyeball when the "red light" light enters the eyeball to form an image is cornea-pupil-crystalline lens-retina, and the driver's complex reflex when seeing a red light. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>