Many students are doing no hard work in their studies. Their achievements are not improved, but their efforts are not rewarded, and they gradually lose their motivation to struggle It focuses on the principles of learning methods. What does it take to succeed in anything? The method is only one aspect. No matter how good the method is, it cannot succeed without the support of its own quality. The following is a summary of learning methods organized by my editor for you. I hope it will be helpful to you. Welcome to read and learn!
How did the later biology review? It can be said that it has been separated from textbooks.
Close your eyes, and the nature with rich species emerges in your brain. There are all kinds of creatures, including single cell organisms, multicellular organisms, and of course, we humans are at the core.
A healthy human body is in a steady state of dynamic balance. All organs work together to maintain the steady state balance. What is the role of each organ (such as islets of langerhans)? What do you secrete? What is the chemical nature of secretion? Organs are composed of different cells. What organelles do cells have? How to identify? What are the functions of each organelle? What chemical reactions are going on in these organelles? How to write the reaction equation? Cells are composed of molecules. What are the components of cell membrane? What's the role of protein in it? What is infiltration, free diffusion and active transportation? What are the functions of protein, lipid and sugar?
What is the molecular formula? What can it be generated from?
From human body stability to natural stability, to food chain, to energy transmission, to population density, to biodiversity, to human continuity (genetic law), to what related problems you have done, to what you have missed
It doesn't need anything, just close your eyes, and you can go through the whole high school physics, biology, chemistry, and mathematics in your head again. This is what I said that learning doesn't care about form.
The perfect knowledge system can only be created through countless rounds of questions and textbooks if you want to be extremely proficient in the material elements and cells, genetic laws, steady state and other major modules.
To answer the biology question, we should study the refinement of the answer terms! I often study the answers to the biology college entrance examination questions. The language is airtight, neither too detailed, to avoid knowledge mistakes, but also very professional and reliable. This is the way to solve the biology questions
Just like biology, it is actually not difficult. As long as you know, understand and master the things to be tested, you can get the answer after a little analysis. But if you have no foundation, how do you answer?
First, the role of pigment: absorption, transmission and transformation.
The specific process of photosynthetic respiration and the factors affecting photosynthesis are omitted here; Next, we will go directly to the collation of common images of photosynthetic respiration. (This is the result of many years of problem solving. Generally speaking, teaching aids will not summarize these knowledge.)
Classic image 1: sine like function image
Applicable background: green plants in sealed glass cover
(It seems strange in this picture that the carbon dioxide concentration can still be negative, which should mean the concentration compared with the carbon dioxide concentration in the initial glass cover)
Section AB (0-2:00): in the early morning, plants only breathe and emit carbon dioxide.
Section BC (2-6 hours) (2-5 hours according to our teacher): Plants still only breathe, but the difference is that the temperature decreases and the respiration rate slows down.
CD segment (6-8 o'clock): when the sun rises, plants begin photosynthesis, but have not reached the light compensation point.
Point D: plants reach the light compensation point, that is, the intensity of photosynthesis is equal to the intensity of respiration. Then the carbon dioxide concentration began to decrease.
DE segment (8-11 hours): the intensity of photosynthesis is greater than the intensity of respiration, and the plant begins to have a net accumulation.
Section EF (11-14:00): lunch break. If the temperature is too high, in order to prevent transpiration and water loss, the stomata will be closed, the intercellular carbon dioxide will increase, the carbon dioxide absorption will decrease, the dark reaction rate will decrease, and then the total (net) photosynthetic rate will decrease.
FG section (14-18:00): lunch break is cancelled. The net photosynthetic rate increased.
G point: the plant reaches the light compensation point.
GH point (18-20): temperature decreases, light weakens, and respiration is stronger than photosynthesis.
HI point (20-24 hours): the light disappears completely, and the carbon dioxide concentration increases rapidly.
Since the two pictures found are put together, let's talk about them together.
A figure: As a comparison between the two things, this article focuses on the characteristics of shade plants, and the comparison of characteristics of sun plants can be deduced.
Shade plants are suitable for low light environment. Under certain weak light conditions (not too weak), shade plants will grow better than sun plants. In the process of community succession, when tall trees gradually become dominant species and light is robbed, some plants that can tolerate weak light are naturally selected.
Shade plants have thick leaves, large and many chloroplasts, and higher efficiency of photosynthesis, so the light compensation point is also higher. Another reason is that the respiration intensity of shade plants is weaker than that of sun plants when there is no light.
Shade plants have low light saturation points, which can also be regarded as a result of natural selection.
Improve the utilization rate of light: shade plants and sun plants are intercropped.
Chart B
What can we do with this picture? We can extract information. Don't feel boring. The college entrance examination is about extracting and summarizing these strange questions.
Just look at one curve. This is a common bell curve of net photosynthetic rate changing with temperature. What about another? There is more information.
First, we found that the atmospheric carbon dioxide concentration is not saturated. This means that we can improve the photosynthetic rate by increasing the concentration of carbon dioxide.
What is the significance of the length of the difference between the two curves at the same temperature? That is, the increase in photosynthetic rate from atmospheric carbon dioxide concentration to saturated carbon dioxide concentration. We can find that this increase is the largest at 35 degrees.
So, how can we increase the carbon dioxide concentration? It is feasible to apply dry ice and organic fertilizer. Organic fertilizer, also known as farm manure, can supplement trace elements, but what does it have to do with carbon dioxide? The reason lies in the decomposition of microorganisms (respiration is an important part of decomposition, which is the inclusion relationship). This process is relatively slow.
In addition, it is also necessary to accelerate the air flow so that carbon dioxide can be replenished at any time. This is the same reason as opening the window for ventilation. "Correct the wind and get through the air" is a classic summary.
Secondly, we find that the optimal temperature of the two curves does not coincide, that is, the optimal temperature is also related to the carbon dioxide concentration.
This is a bivariate problem, so we can speculate that the concentration of carbon dioxide affects the activity of enzymes. You are welcome to consult the literature for the specific reason.
Under the influence of two variables, the results are often variable. For example, in the experiment under the condition of bivariate combination, the combination of two optimal conditions may not be the best, because the two variables may have the superposition or exclusion effect, which also leads to the deviation of results. This is a special point to pay attention to when doing biological experiments.
Of course, some bivariates are also unaffected. For example, under different temperatures, the optimal PH is the same.
Later, we can also find that the effect of temperature on saturated carbon dioxide concentration is more obvious. (The curve fluctuation amplitude is greater) When carbon dioxide reaches saturation and is no longer a limiting condition, temperature naturally becomes the main factor affecting photosynthesis, so the effect of temperature is obvious. When the concentration of carbon dioxide is low, there is insufficient carbon dioxide to limit the growth of photosynthetic rate, resulting in small changes in photosynthetic rate.
According to high school chemistry knowledge, sodium bicarbonate can only be decomposed into carbon dioxide when heated in solid state.
After checking with the teacher, I came to the conclusion that this device was funny.
If such a powerful solution really exists, we will reluctantly call it carbon dioxide buffer.
In fact, the inspiration of the wrong device came from this experiment: irradiate the leaf discs in different concentrations of sodium bicarbonate solution with light, and observe the time when the leaves float up.
Because the leaves produce oxygen through photosynthesis, the gas lifts the leaves up. The stronger the photosynthesis is, the more oxygen is produced per unit time, and the shorter the floating time is.
In sodium bicarbonate solution, carbon dioxide will be produced with the increase of solution acidity. The higher the concentration is, the more carbon dioxide will be produced, and the floating time will naturally shorten. Then why did it take longer? The reason is the same as that of putting leaves into high concentration sucrose solution, osmotic dehydration will inevitably affect photosynthesis.
The above experiment is a modification of the textbook experiment. The experimental device of the original textbook is as above (the textbook uses small round leaves instead of algae). The light intensity is adjusted by the distance between the incandescent lamp and the plant, and then the effect of light intensity on photosynthesis is explored.
Some teaching assistants pointed out that it is better to use bulbs such as energy-saving lamps, because incandescent lamps produce heat (which can be regarded as converting all electric energy into heat energy), which will affect the experimental results.
The amount of CO2 absorbed under light reflects the net photosynthetic rate, while the amount of CO2 released under darkness reflects the respiratory rate. The true photosynthetic rate is the sum of the values of the two curves. It can be seen that the total photosynthesis is the strongest at about 35 degrees.
Later, we can speculate that the true photosynthetic rate will decline after 35 ℃, and reduce to 0 at about 45 ℃, and the optimal temperature of respiration will be higher than photosynthesis (this is a general rule), about 40 ℃, and then it will decline.
Of course, this also varies from plant to plant, because the enzymes of each plant are different (the basic reason is that the genetic material is different), and the above optimal temperatures are generally applicable in this type of plants.
However, the growth of plants mainly depends on the net photosynthetic rate, so 25 ℃ is the optimal growth temperature for plants.
Now that we talk about temperature, how can we increase the output in agricultural production?
The premise is to cultivate in greenhouse.
Properly increase the temperature during the day (the word "appropriate" is something you need to learn to use, and it is likely to be a stepping point), photosynthesis will speed up, and respiration will also speed up. Of course, you should believe that the word "appropriate" ensures that the photosynthetic rate increases faster.
Lower the temperature properly at night to reduce the intensity of respiration.
The large temperature difference between day and night is conducive to the accumulation of organic matter, and the reason is clear at a glance.
