Stomatal opening experiment, why does the leaf epidermis need to be illuminated after being put into

In the stomatal opening experiment, the reason why the leaf epidermis is illuminated after being put into the solution is to promote stomatal opening. This role is mainly related to photosynthesis and the water potential of guarding the cell.

Under photosynthesis, chloroplasts in the guard cells of the leaf epidermis photosynthesize, resulting in a decrease in CO2 concentration, causing an increase in pH. According to the starch-glycoconversion theory, starch phosphorylase promotes the conversion of starch into glucose-1-p, and the intracellular glucose concentration increases, and the water potential decreases.

When the water potential of the guard cell drops, it will absorb water and expand, and the stomata will open. This is because under the influence of light, the chloroplasts of the guard cells photosynthesize and cause the CO2 concentration to decrease, causing the pH to increase, which in turn promotes the conversion of starch to glucose-1-P, the intracellular glucose concentration increases, and the water potential decreases.

Therefore, illumination can promote stomatal opening.

Summary. Temporary loading of leaf epidermis is made.

Drop one to two drops of water on the slide** and set aside. Take the green cabbage leaves inserted into the water (or shriveled), fold them inward from the back respectively, and then gently tear and pull from the fold, there is a white film (i.e., the lower epidermis) at the broken place, use tweezers to pick up a small piece of white film, put it in the water droplet of the glass slide, flatten it, and cover the coverslip. It is made into a temporary film.

Observe the leaf epidermis with a microscope.

Take the mirror and align the light. When the prepared temporary mount is placed under a low-magnification microscope, many irregularly shaped epidermal cells can be seen, as well as pairs of half-moon-shaped guard cells and stomata formed by the gap between guard cells. When observing the temporary loading of the leaf epidermis inserted into the water, it is observed that the stomata are greatly opened; When temporary mounting of the shriveled leaf epidermis is observed, stomatal closure is observed.

This distinguishes when the stomata are open and when they are closed. (If the stomata in the field of view are small, you can use a 40 high-magnification lens for observation).

Drawing. Draw 4-5 connected leaf epidermal cells and a stomata surrounded by 2 guard cells with a pencil and note the names of each part.

Put away the camera and clean the table.

Stomatal opening experiment, why is the leaf epidermis illuminated + after being put into the solution? What is the underlying mechanism?

See if the leaf epidermis is photosynthesizing.

What is the internal mechanism.

Verify that the leaf epidermis undergoes photosynthesis to produce oxygen.

How is leaf epidermis taken for microscopic examination? Please describe the complete experiment.

Steps. Ask about custom messages].

Classmates, this kind of big question takes too long, you can take a picture of this and continue to explain it for you.

The big question? It's not a big deal.

Make a temporary mount of the leaf epidermis on a glass slide** with one or two drops of water and set aside. Take the green cabbage leaves inserted into the water (or shriveled), fold them inward from the back respectively, and then gently tear and pull from the fold, there is a white film (i.e., the lower epidermis) at the broken place, use tweezers to pick up a small piece of white film, put it in the water droplet of the glass slide, flatten it, and cover the coverslip. It is made into a temporary film.

Use a microscope to observe the leaf epidermis, take a mirror to call the shield, and turn the light. When the prepared temporary mount is viewed under a low magnification, many irregularly shaped epidermal cells can be seen, as well as pairs of half-moon-shaped guard cells and stomata formed by the gap between guard cells. When observing the temporary loading of the leaf epidermis inserted into the water, it is observed that the stomata are greatly opened; When temporary mounting of the shriveled leaf epidermis is observed, stomatal closure is observed.

This distinguishes when the stomata are open and when they are closed. (If the stomata in the field of view are small, you can use a 40 high-magnification lens to observe) Draw 4-5 connected leaf epidermal cells and a stomata surrounded by 2 guard cells with a pencil, and indicate the name of each part. Put away the camera and clean the table.

<> hope that the students will give a thumbs up after asking.

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Choose C, of course it's not. The stomatal opening generally increases with the rise of temperature, reaching the limb and hand blind to the maximum at about 30, and the stomata can not be opened well at low temperature (such as below 10) despite long-term light, mainly because the activity of starch phosphorylase is not high, and the temperature is too high will lead to too strong transpiration, and the stomata will be closed due to the loss of water in the guard cells. The chloroplasts of the guard cells carry out photosynthesis under light, using CO2 to increase the intracellular pH value, starch phosphorylase hydrolyzes starch into phosphate glucose, and the intracellular water potential decreases. When the soil is moist, coupled with high temperatures and strong sunlight, the stomata open in order to evaporate the water to dissipate heat and at the same time provide transpiration pull to transport minerals to the upper part of the plant.

To sum up, you should choose A. for this questionI don't know if I'm right? ,10,Choose a Look at the paragraph below page 114 of the biology book in the first volume of the seventh grade.,It's well explained.。

2. It seems that the textbook says that most of the stomata are narrowed or closed at night.

I think a sufficient amount of water, light, high temperature, strong transpiration, insufficient water is dry, stomata will close for protection, of course, at noon transpiration is too strong, and it will be closed, 1, a soil is moist, light, and the temperature is high, 1, The stomata open is large, indicating that the light and the effect and transpiration are strong, who divides the evaporation fast, so it should be a, the humidity means that the roots are not short of water, the light indicates that the root water supply is needed for light and action, for inorganic salts, the higher the temperature is conducive to transpiration, higher than very high, the stomata will be closed, 0, b, 0, the same plant under the following experimental conditions, the largest degree of leaf stomatal opening is the sky

a Moist soil with high light temperature.

b Moist soil, low light and temperature.

c The soil is moist, dark and the temperature is low.

d The soil is dry, the light is high, and the temperature is high.

I chose C, right?

1) This question can be drawn according to the table Plants show a trend of first falling and then rising, and the general trend of plants is to rise first and then fall, but there is a short downward trend in the middle of the day, which is due to high temperatures

2) According to the table analysis, the plants closed their pores during the day and opened their stomata at night, so the plants mainly absorbed CO2 at night

Plant II has a small stomatal opening at night and a large pore opening during the day, so the plant mainly absorbs CO2 during the day

3) Desert climate due to the high temperature during the day, plants in order to maintain water stomata in the white matter to let the sky close, open the silver silver open at night, so the desert stomatal conductance change is closer to plants, the main environmental factors affecting its photosynthetic intensity in addition to water and CO2

In addition to concentration, there are also light, temperature, inorganic salts, etc

4) In the figure, it represents the decomposition of organic matter by plant respiration, and represents the synthesis of organic matter for photosynthesis At 3:00 a.m., both plant I and plant II can only respire C3 produced during respiration

Is pyruvate process denoting the light reaction of photosynthesis, denoting the dark reaction of photosynthesis, the dark reaction process requires the catalysis of enzymes, and also needs the [H] and ATP provided by the photoreaction H the answer is:

2) Plants absorb CO2 mainly at night

Plants absorb CO2 mainly during the day

3) Light, temperature, inorganic salts, etc.).

4) Pyruvate [H] and ATP

a. The independent variable in the experiment that verifies that photosynthesis requires light is the presence or absence of light, and wrapping half of the leaf in black paper is the control independent variable, which does not belong to the control irrelevant variable, and a is correct;

b. In the experiment to verify that temperature affects enzyme activity, temperature is the independent variable, and first placing each group of substrates and enzyme solutions at the same temperature for an appropriate time and then mixing them is a control independent variable, not a control independent variable, and B is correct;

c. In the experiment to verify that photosynthesis can produce starch, the original starch in the plant is an irrelevant variable, and the experimental plant is starved first to eliminate the influence of the original starch on the experimental results, which belongs to controlling the influence of irrelevant variables on the experimental results, c is wrong;

d. In the extraction and separation experiment of pigment in green leaves, the edge of the paper tape has more contact interface with air, and the diffusion speed of chromatography solution at the edge of the paper tape is faster than that inside

Therefore, ab

The purpose of the experiment is to verify that the leaves have gas production and consumption in the process of photosynthesis and respiration, which are two aspects, which can be analyzed by the dilute solution of sodium bicarbonate, which can produce carbon dioxide and absorb carbon dioxide According to the experimental procedure given "one group adds sodium bicarbonate dilute solution, and the other group adds the same amount of distilled water", it can be seen that the essence is whether there is carbon dioxide, so it should be verified whether photosynthesis produces oxygen, and the conditions should be illuminated The gas produced by the carbon dioxide provided by the dilute solution of sodium bicarbonate can make the leaves rise without carbon dioxide** can not carry out photosynthesis and then give dark treatment, respiration will consume oxygen, and the leaves will sink So the answer is:

3) Place these two test tubes under a fluorescent lamp and illuminate them for a period of time Result: The leaves in the dilute solution of NaHCO3 float up, and the leaves in distilled water are still at the bottom of the tube (4) Put the two tubes in a dark incubator for a while Result: The leaves in the dilute solution of NaHCO3 sink and the leaves in distilled water are still at the bottom of the tube Result of analysis**

1) Under light, naHCO3

The leaves in a dilute solution undergo photosynthesis, releasing O2

More O2 than is consumed by respiration, O2 in the intercellular space of the mesophyll increases, leaves float and there is a lack of CO2 in distilled water

and O2, the leaves are not capable of photosynthesis and aerobic respiration, and there is a lack of gas in the mesophyll intercellular space, so the leaves remain at the bottom of the tube

2) In the dark, nahco3

The leaves in the dilute solution undergo respiration, which consumes the O2 in the intercellular space of the mesophyll, and the CO2 released is dissolved in NaHCO3

In dilute solution, there is a lack of gas in the mesophyll intercellular space, and the leaves sink There is a lack of O2 in distilled water, and the leaves cannot undergo aerobic respiration, and the mesophyll intercellular spaces still lack gas, so the leaves are still at the bottom of the test tube

In the metabolism of gases such as photosynthesis, respiration, and transpiration, the stomata become the pathway of air and water vapor, and the convex lens-shaped pores formed between the guard cells are called stomata Its throughput is regulated by the opening and closing of the guard cells The guard cells are thin in the inner wall and the outer wall is thicker, when the guard cells absorb water, the cells swell, the cell thickness increases, the two cells are separated, and the stomata are opened. The transpiration proceeds smoothly and promotes the absorption and transport of water and the transport of inorganic salts. When the guard cells lose water, the cells shrink, the cell thickness decreases, the two cells merge, the stomata close, and when the stomata are closed, the air cannot enter and exit, photosynthesis cannot obtain carbon dioxide, and respiration cannot obtain oxygen, and it cannot proceed smoothly; Similarly, water vapor cannot be dissipated through the stomata and transpiration is not smooth, which also hinders the absorption and transport of water and the transport of inorganic salts

So the answer is:

Although I don't see the diagram, I can see from the question that the answer should be dead D, and the gas collected by option A is the oxygen of net photosynthesis, that is, the oxygen that is consumed by removing respiration. Option b has bubbles, it doesn't have to be oxygen. c, sodium bicarbonate can only maintain the concentration of carbon dioxide in the air.

This is generally the case for option d**. This is my understanding.