Sincerely ask for help!! Having some difficulties studying high school biology!

First of all, biology can be said to be the same as chemistry "liberal arts and science", the reason is that the characteristics of these two subjects are scattered knowledge points, the amount of calculation is not large, and the knowledge and memorization are many and miscellaneous. Generally speaking, when learning biology, memorization is the first priority, it is not like memorizing formulas like mathematics and physics, but more attention is paid to memorizing basic knowledge, and it is extremely common to memorize biology books. However, biology is still science after all, and for science, understanding is a more important thing, and the reason why we pay attention to drawing inferences from one case and touching on others is because only by understanding can we use it freely.

Biology, understanding the concept is the basis for learning, for example, there is a concept of the chromosome, if you can't understand, then this kind of topic must be hanging, when you understand the knowledge of the textbook, you also need to learn from it to solve the problem, then a good teaching aid is quite important, the use of teaching materials, dig deep into the knowledge that is not in the textbook, first think about the applicability of this knowledge, think about how it can be used, when you feel that you have a deeper understanding of it, you can find some conceptual basic questions, See if your understanding is correct, and then seek some other question types of this knowledge point, to see if you can solve it (now a lot of materials focus on learning and practicing, one by one knowledge point practice, which is very good), and then continue to learn, and then do comprehensive exercises, in the practice to focus on reviewing knowledge, think about what part of the content of this test, what method to use, if you have time, you can also try to seek more solutions or clever solutions. One thing I remember most deeply is that my teacher once said, "You must always gain something to do so many questions."

Yes, there must be a harvest to do the problem, and the harvest is the review of thinking methods and knowledge, and solving a problem and solving a hundred problems not only requires a deep understanding of the concept, but also requires a set of standard general methods (of course, sometimes it is necessary to be clever and innovative, which can save time, and cannot always stick to one method). Biology also has a characteristic of open thinking, biological experiments are varied, and the test methods have their own characteristics, but they will not leave a knowledge point after all, to grasp the characteristics of this knowledge point, plus their own open thinking, combined with thinking methods to solve problems, we do questions are to summarize the method. You must do the questions with such a mentality in order to gain something.

I'm also a person who advocates problem-based learning, but I never expect to do all the problems at once, because it's impossible, and I want to do more questions to consolidate the thinking method, and at the same time I hope to see some good question types, and when you see you solve one problem after another with the methods you explore, that sense of comfort is quite satisfying.

The above are some of my experiences and opinions, I hope it will be helpful to you.

I don't know what grade you are in high school, if you are one or two, don't worry, the teacher in the third year of high school will reorganize and summarize all the knowledge, and I have encountered similar problems in the third year of high school, the most important thing is that the basic skills are solid, and it is not enough to do the questions.

Previous bioscience experience:

1. Induction, summarize the knowledge points of all the books to form your own notes, just look at the useless things in the book is not equal to what you master, this is the best way to integrate scattered knowledge. After reading through each chapter, you can use a mind map (that is, a knowledge tree) to recall the knowledge points, no need to draw very fine, but to master the context structure of the key points of the whole chapter, and leave a clear structure in your mind, which will improve your knowledge positioning and associative ability to do the question, which is usually guided by the senior high school teacher, but it is not enough, all the knowledge points must be memorized, memorized very well, and the knowledge points are constantly repeated and consolidated through each question.

2. It is very important to improve the method quickly but must insist, do not seek more refinement, every time you do the big and small questions, all with the wrong question book carefully analyze and induct the positioning of knowledge points, this is a very cumbersome but very effective process, remind you that you are wrong, you will find yourself improved for a period of time.

These are my experiences, I hope it will help you improve, students can not be impetuous and trickle, grasp every mistake steadily, every time is an opportunity for you to improve.

High school knowledge is indeed scattered, but this knowledge is also very shallow. But when it comes to what you said about doing questions, if you feel that your knowledge is not enough, it means that you may not have grasped the test point, or even if you have grasped the test point, you have not yet understood the test point, which causes you to not know how to do the test questions. In fact, if you analyze the exam papers, you will find that there are only a few knowledge points that can be tested in high school, and it is good to study the test points thoroughly and solidly.

I remember when I took the college entrance examination, there were a total of six multiple-choice questions and two major questions in biology, and I took so many aspects of the test, and I learned it thoroughly.

When doing the questions, connect the small knowledge, form a knowledge framework in your mind, go to the Internet to find some biological knowledge points, and connect them, I hope it will help you.

You have a network of knowledge formation, and scattered memories of knowledge are of little use...

Pay attention to the establishment of a knowledge network and the knowledge learned systematically in a timely manner.

Higher animal egg cells minus 2 metaphase have no homologs.

In general, a plasma cell can only secrete one type of antibody.

B These two types of diabetes are autoimmune diseases, this sentence is easy to understand, the first is the antibody secreted by a cell to attack the glucose receptor on the membrane of pancreatic B cell cell, which means that the antibody attacks the cell secreting insulin, destroys the glucose receptor of pancreatic B cell cells, so that the cell can not use glucose, starvation to death. As a result, the body cannot produce insulin, but it can be injected outside the body.

c The cells that produce antibodies are plasma cells and do not have the recognition function, only B cells, T cells, etc. have the recognition function.

d The insulin produced by pancreatic B cells binds to receptors on the target cell membrane, indicating that the cell membrane has the function of information transmission, which is obviously correct.

a.A plasma cell can secrete only one type of antibody.

1. As can be seen from the figure, under the condition of 25, the net photosynthetic rate value is and the respiration rate is; Note: The net photosynthetic rate has been removed from the respiration consumption, so the net photosynthetic yield of 12h of light is, while the amount of respiration consumed is only in the darkness of 12h. In order for plants to grow, the net photosynthetic yield should be greater than 0, and it can be seen from the above values that the net photosynthetic yield is that the plant can grow normally.

2. The same as the above question: plants should be able to grow, and the net photosynthetic yield should be greater than 0. In this question, net photosynthetic yield = true photosynthetic production - respiration.

It can be seen from the figure that the most suitable temperature for plant growth should be the temperature point with the largest difference between the real photosynthesis rate and the respiration volume, that is, at 30, the difference is 5 blocks, and the others are less than 5 blocks.

If under 20 conditions, the net photosynthetic yield is grid (the difference between the real photosynthetic amount and the respiration volume), and the respiration volume is 2 grids, according to the conditions in the question, the net photosynthetic yield is grid x12 and the respiration volume is 2x12, and the difference between the two is negative, that is, the net photosynthetic amount is less than the respiration volume, so the plant cannot grow normally.

The photosynthetic rate in these two questions is different, the net photosynthetic rate in the first question is the net photosynthetic rate, and the second question is the real photosynthetic rate, and these two questions test the same test point: net photosynthetic yield = real photosynthetic production - respiration. If you want to get it right, you have to study these three quantities carefully.

The difference is very obvious, and there are two main points.

One. The two graphs are completely different: Question 1 is titled "Net Photosynthesis Rate and Respiration Rate Curve" and Question 2 is "Effect of True Photosynthesis Rate and Respiration Rate" The so-called "net photosynthesis rate" represents pure accumulation, while "true photosynthesis rate" needs to deduct the organic matter that is accumulated during the same period of respiration consumption. The conditions are light and darkness are halved, so as long as the accumulation of light is greater than the consumption of darkness in question 1, normal growth can be guaranteed (that is, there is accumulation overall), which can obviously be done; In Figure 2, the difference between photosynthesis and respiration is still greater than the rate of respiration, which is obviously not possible.

Two. The conditions are different Question 1 is "Keep the temperature at 25" and Question 2 is "If the temperature is kept at 20", the temperature is different, the conditions are different, and the accumulation amount is naturally different, for example, if the temperature is also 25 in the 2nd question, then the answer is the same as 1.

That's basically it, welcome to ask.

Figure 1 is net photosynthesis. Figure 2 is the photosynthetic rate. At 20, CO2 absorption is 3, production is 2, respiration is 24 hours, and photosynthesis is 12 hours.

12x3<2x24 So picture 2 can't. Figure 1 Net Photosynthesis 25 The actual photosynthesis should be net photosynthesis 4+ respiration The same respiration is 24 hours, and photosynthesis is 12 hours, so the first picture is that it can grow normally.

The first question is about the net photosynthetic rate, and the second is the actual photosynthetic rate. The actual photosynthetic rate is equal to the net photosynthetic rate plus the respiration rate.

In the first question, at 25 degrees, the amount of organic matter accumulated in a day is 12(h)>0 (the net photosynthetic rate rate has been removed from the respiration rate when light is removed).

In the second question, the amount of organic matter accumulated is: <0

Steps: After 10 minutes, iodine solution should be added to allow salivary amylase to break down the starch first.

Conclusion: Saliva contains amylase, which breaks down starch into maltose. Saliva should contain salivary amylase (unlike amylase), and this experiment does not prove the breakdown of starch into maltose.

1. Filin reagent should be used to test whether maltose is generated;

2. The first step should be reversed, the test tube should be shaken for 10min, the test tube should be taken out, and then the Felin reagent should be added dropwise to the test tube, and heated in a boiling water bath for 5 minutes to observe the change of the color of the solution;

3. If there is a lack of control, take another test tube and add 2ml of distilled water in step 3, and the other processes are the same as after correction.

There doesn't seem to be anything wrong with that.

Hello lz.

First of all, the third-to-last empty is 20, no doubt.

So far, we know that at the optimal temperature, calculated as carbon dioxide, let the photosynthesis rate be v1 and the respiration rate be v2

v1-v2=

v2=1, so v1=

After 12 hours of light, photosynthesis consumes carbon dioxide throughout the day.

Respiration consumes carbon dioxide.

1x24=24mg

Occurs by aerobic respiration in the total reaction formula of photosynthesis.

6co2～c6h12o6

Organic matter can be made by substitution.

Consumption of organic matter.

Net manufacturing of organics.