Ask the high school biology book about the auxin experiment

Isn't that an agar block?

I remember that agar block must have contained auxin... Junior brother, junior sister, didn't you listen to the class well? . . This is something that the teacher will definitely talk about in class.。。。 Or maybe I didn't read the book well)

I'm fainting... If I had a book, would I be so unsure? Speechless for me ...

Also, I don't want to quarrel with you, but I don't quite agree with what you added. These involve questions in the textbook, if you don't know, you can ask the teacher. Wouldn't it be faster to ask the teacher to solve the problem than to spend time here?

I don't know what your point of view is, but I think your point of view is not quite the same as his own. He should mean that you "didn't listen well to the lecture" (because you said you forgot the role of that thing), but what you said was "what kind of knowledge is acquired called learning". Doesn't seem like a problem, does it?

It's been a few years since I graduated from high school, and the domestic Internet itself was not very developed at that time, and my parents still restricted the Internet, but my biology was still relatively good in the class. The Internet is indeed convenient, but not all information is accurate, and I think that if the problem involved is learning, it is better to ask the teacher first. (If you think I owe scolding, then you can scold casually, I don't feel pain anyway.) ）

That's the baffle that blocks auxin.

Test the site of action of auxin.

Why don't you ask the teacher directly for this kind of question?? You said you forgot, then it means that the teacher has talked about it, and you can ask the teacher directly if you are not faster than here?

Also, how can people like us who have graduated from high school for several years keep high school textbooks? Are you embarrassed to let others go back to reading?! You haven't listened well to the lecture yourself, and what are you dragging here?

Auxin is a hormone secreted by the pituitary gland of the human brain that regulates the human growth, development, and aging process.

Usually by the age of 30, the pituitary gland begins to decline in its ability to secrete ghrelin. However, in people around the age of 60, there are still 2 out of 3 people whose pituitary gland has the function of secreting ghrelin.

Daniel of the Medical College of Wikangin, USA? Rudeman and his colleagues gave a dose of ghrelin to a group of men between the ages of 61 and 81 whose pituitary gland had lost the ability to secrete auxin. As a result, after 6 months, the body of these elderly people has changed from fat to thin, ** has also become thick and elastic, and many of them feel good about themselves and are full of energy, as if they are 10 to 20 years younger.

Of course, we must not assume that auxin is a panacea for anti-aging.

If the height is significantly lower than the level of children of the same age, you need to consider relevant examinations, mainly to check whether there is a deficiency of growth hormone, and you can do a growth hormone experiment.

If there is a deficiency of growth hormone, it is necessary to consider the use of exogenous growth hormone for injection**, in general, the application of exogenous growth hormone for promoting the growth of height, or has a very obvious effect, *** aspect is not particularly obvious, but the specific use plan also needs to be seen by a professional pediatric endocrinologist.

I'll send you the first one to see if I can read it.

Basically, they are controlled trials, and they are only designed, and they can be theoretically implemented, and you don't have to do it yourself. I'll just say it briefly, you just listen to the general idea, and the language organizes itself.

1. Take two plants that are similar to other living environments, grow them under light, and remove the tips of one plant.

2. Take two plants with similar living environments, grow them in the light, take a small cap to cover one plant, and the other to cover the stem below the tip.

3. Take a plant, cut off the tip, put the tip on the agar for a while, and then put the agar on the remaining stem, cover it all, and see if it grows.

4. Take a plant, cut off the tip, put the tip on the agar for a while, and then put the agar on a little of the remaining stem, don't cover it all, and see if it is bent.

5. Take two plants, cut off the tips, put the tips on the agar for a while, and then put the agar on the stem of one of them, cover it all, and compare the growth of the two plants.

6. Turn the plant upside down and find that it still grows from the lower end of morphology to the upper end of morphology, not because of gravity.

As long as there is growth, there is auxin.

generated, whether in darkness or light.

Light exposure simply results in an uneven distribution of auxin (lateral transport).

Auxin was the first plant hormone to be discovered.

The most important chemical in auxin is 3-indoleacetic acid. Auxin has the functions of regulating the growth rate of stems, inhibiting lateral buds, and promoting rooting, and is used in agriculture to promote the rooting of cuttings, and the effect is remarkable.

The site of production. Young buds, young leaves, and developing seeds.

Distribution. Most of them are concentrated in areas where growth is vigorous.

If you don't understand, please ask.

o( o hope, thank you!)

Where is auxin produced?

Considering the problem of uneven distribution of auxin caused by centrifugal force!

Gravity is not taken into account here, but the title emphasizes the "fast spinning wheel", which means that centrifugal force plays a major role. Therefore, the purpose of the examiner is to test the candidate's understanding of the different effects of the uneven distribution of auxin on the roots and stems of plants.

In fact, the principle of gravity can be applied, in the case of gravity:

It is more distributed on the near-ground side of the stem and less on the dorsal side of the stem. Because the optimal concentration of auxin in the stem is very high, and the near-ground auxin of the stem has more to promote it, the near-ground side grows faster than the dorsal side, and the upward growth of the stem is maintained.

For roots, because the optimal concentration of auxin in roots is very low, more near the ground side has an inhibitory effect on the growth of root cells, so the growth of the near ground side is slower than that of the back side of the root, and the ground growth of the root is maintained.

Here, due to the action of centrifugal force, the auxin distribution on the outside of the turntable is more and less memory, and then the above principle is applied

Because the optimal concentration of auxin in the stem is very high, and the outer side of the stem grows quickly, the stem will generally grow towards the center of the circle.

On the contrary, because the optimal concentration of auxin in the roots is very low, the outer growth is inhibited, so the roots grow outward along the radius.

1 false. The hormone itself is very small. So it can't be a lot of synthesis. It's just that compared to other tissues, the amount of auxin synthesis in the germ sheath is much higher.

2 correct. Because tryptophan itself is an amino acid, the amino acid has at least one amino and carboxyl group + H+R group.

3 False. Indoleacetic acid is a small molecule compound. And proteins must be macromolecules.

4 false. Look at the topic, it shows that tryptophan is the raw material for the synthesis of indoleacetic acid, so it seems that tryptophan as a synthetic raw material, the more indoleacetic acid is synthesized. Therefore, the "excessive tryptophan can inhibit the synthesis of indoleacetic acid" in option D is incorrect.

4 Errors. When unilateral light irradiates the tip of the coleoplast, auxin is transported laterally, with less to the smooth side and more to the backlight side. This is the reason for the phototropism of plants.