Biology High School Topics, High School Biology Topics

1.There is omnipotence. First of all, the expression of totipotency in plant cells is much easier than in animal cells (e.g

Carrot tissue culture) Although the somatic cells of animals have a full set of genes, they can only develop into tissues and cannot develop into new individuals in the case of stereoculture. Therefore, myocytes cannot be used instead of stem cells to culture tissues and organs.

1. Cell-free totipotency, if you replace stem cells with muscle cells, you can't lose your totipotency.

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1. The nucleus has totipotency, the cell as a whole does not, as for the culture of tissues and organs, the Japanese scientist Shinya Yamanaka studied in 07 years to introduce four genes into ** cells to dedifferentiate them into stem cells.

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1.Yes, as long as it is a living cell, it is totipotent. Because cellular DNA contains the entire set of genetic material of the organism! However, it is not yet possible to grow muscle cells into tissues and organs! Because there is no way to dedifferentiate muscle cells!

1. High school biology books say that "highly specialized animal cells are still totipotent" because highly specialized cells contain all the genetic material and the entire set of DNA of the animal.

Highly differentiated cells of animals are totipotent, but until now, it has not been possible to use muscle cells instead of stem cells in the laboratory to grow tissues and organs, and I believe that such a day will come in the future.

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1 has totipotency because it has a full set of genes but can only develop into tissues and not into new individuals in the case of stereoculture, 2, ABCD

1.The egg cells of animals are highly differentiated and totipotent, while others do not

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Question 1: No, such as sperm cells, egg cells.

Question 2: ABCD

Summary. High School Biology Topics.

Good. Hello dear, the answer to this big question has been sent to you, please look carefully at what the teacher thinks you wrote on paper.

You'll have to figure this out for yourself. The title tells you that it takes 1 year to sow and harvest peas. So.

The first process is the height of the stem, it takes 1 year to get F1, and it takes 1 year to get F2, but pay attention to the seeds of F2 that we get at this time, and you can't see the phenotype of his height by the seeds alone at this time, so you have to put F2 down and grow it in the spring of the third year before you can observe, but it's not 3 years.

The second process is the color and shape of the seeds, and it takes 1 year for F1 to be wrinkled with pure yellow and pure green, and 1 year for F1 self-breeding. A total of 2 years. Note that the yellow and wrinkles of the obtained seeds can not be directly observed with the naked eye? You don't have to plant it for 1 year like looking at the stems.

The height of the stem can not be observed until the F2 pea is planted and grows into a plant, so it takes 3 years; The color of the pea seed coat and the shape of the seed are all indicative of the seed, which can be observed in the seeds harvested the following year.

Green is the seed coat, the seeds must be planted, and after growing into plants, self-pollination and pods can be seen, and it takes more than a year.

The tall and short traits can only be expressed when planted in the third year, and the yellow round grains should not be planted, and the seeds in the second year can show the traits.

Let's just say what I understand:

First of all, let's talk about the meaning of transformation: the process by which the target gene enters the recipient cell and maintains stability and expression in the recipient cell, which becomes transformation.

In this question, it can be simply understood that in the case of co-culture, the genes in the original mutant strain and the genes existing in the mutant strain X are "put" together.

X was cultured with J or L, and all 7 gene segments were complete. J is missing a4a5 and a6, and l is missing a4a5a6a7, then it means that these genes are all present in x, otherwise they are "combined" together, and the 7 genes cannot be complete.

Therefore, it can be concluded that X is either lacking A1A2 or A3, so that its genes can be "complementary" to J and L to become complete.

X and K or M are cultured together, and all 7 genes are not complete, either one or that is missing. where k is missing a3a4, m is missing a1a2a3a4a5, then x must be a3.

Otherwise, if X lacks A1 and M happens to have A1, the two co-culture genes are complete.

If X lacks A2, M happens to have A2, and the two are cultivated together.

So, if you want to be incomplete, X can only be missing A3.

I hope you understand

In the first experiment, wild-type appeared, indicating that X's 4567 was not mutated or missing, and could be transformed to obtain wild-type.

The second experiment showed non-wild-type, indicating a deletion of 3 or 4, i.e., a 3 or 4 mutation.

The combination of the above two experiments showed 3 mutations.

There is no shortage of plants that can be cultivated together with X and J or L. And all of them are missing, which means that x does not lack these 3.

Plants co-cultivated with x and k or m are missing. Indicate that X has missing the same fragment as K or M, and A3 or A4.

I've just said that there is no shortage. So what's missing is A3

Permutations and combinations can lead to conclusions.

Co-culture of X with J or L: If all 7 gene segments are complete, X may be missing A1, A2, or A3.

From the co-culture of X and K or M, all 7 genes are not complete, and both K and M are missing A3A4, and then compared with the previous conclusions, it can be seen that X must be missing A3.

Liquid A and solution B of film reagent are mixed before use, and solution A and solution B of biuret reagent are added sequentially, and their concentrations are different from solution A and solution B of film reagent. The two cannot be mixed.

The answer is d.

A: The amoeba is unicellular, and its protrusion of pseudopodia indicates that the cell membrane can be greatly deformed, thus proving that the cell membrane is fluid.

B: Fluorescent proteins disperse, indicating that proteins on the cell membrane can flow on the surface of the cell membrane, thus proving that the cell membrane is fluid.

C: Something like A.

D: This only shows that the cell membrane can selectively permeate certain substances, and what is verified is the selective permeability of the cell membrane, which has little to do with the fluidity of the cell membrane.

Options A and C are similar to endocytosis, reflecting the fluidity of the membrane, while B examines the composition of the membrane with proteins, and the dispersion of proteins means that it is moving, and the fluidity of the natural cell membrane is also reflected. d The main ingredient of ink is ferric tannic acid, which can be absorbed by cells and enter, hence the blue color.

d, d refers to the ink molecules entering the cell through diffusion, which is related to the nature of the substance itself and has nothing to do with the fluidity of the cell membrane.

Cell membranes have fluidity and are related to the movement of phospholipids and proteins.

AIDS is one of the most important diseases that threaten human life. The HIV virus that can cause AIDS is the RNA virus, which infects a person's T lymphocytes, causing a person's immunity to weaken and causing patients to die from widespread infection. Please answer:

1) After the cell enters the cell, it can use (its own RNA) as a template, synthesize (DNA) under the action of (reverse transcriptase), and integrate it into the human genome.

2) After integration, it replicates according to the principle of base complementarity, and can synthesize (RNA) with a (DNA) template, and then synthesize viral proteins through the (translation) process.

3) If the virus is placed outside the cell, the virus cannot multiply, because the virus is an obligate living cell parasite, which has no organelles and cannot independently complete the process of DNA replication, transcription and translation, and must rely on the host cell to live parasitically. ）

(1) Self-RNA, RNA reverse transcriptase, DNA

2) The principle of base complementary pairing, DNA, RNA, translation.

3) Viruses are non-cellular organisms with no organelles and cannot independently complete the process of DNA replication, transcription and translation, and must rely on host cells to live parasiticly.

RNA reverse transcriptase DNA

Principles of base complementary pairing DNA RNA translation.

Viruses have no cellular structure and do not have the ability to metabolize independently.