Study what colors plastic bags are used for plant photosynthesis

The color is produced because the material absorbs different wavelengths of light, white does not absorb any light, and black absorbs all wavelengths of light.

Personally, I still have to look at the material of the plastic bag itself, if it is a thin bag on the market, it is not the best black one, which can absorb most of the light in each band. The second is red, which absorbs more red light, which is also the main light used in photosynthesis, and can also reflect some light in other bands. Again, it's white, and it's like you said, it can reflect some of the light, and it's different from a transparent bag as you said, but if it's thin, it's not as good as black and red.

But if you use a dense and thick bag, which does not transmit any light at all, it doesn't matter what color the surface is, white, black and red are all the same.

Sunset, red glow flies in the west mountains.

The soldiers hit the target and returned to the camp.

Return the camp to the red flowers on the chest.

Pleasant singing was flying all over the sky.

mi sao la mi sao

la sao mi dao ruai

Pleasant singing was flying all over the sky.

The song flew to Beijing.

My heart rejoiced when I heard it.

Praise us for singing well.

Praise us for being the first in marksmanship.

mi sao la mi sao

la sao mi dao ruai

Praise us for being the first in marksmanship.

Under light, plants both photosynthesize and respire, the intensity of photosynthesis exceeds respiration, and the carbon dioxide produced by respiration is consumed by plants for photosynthesis in the plant, so the respiration of plants is not obvious, the condition of photosynthesis is light, and the black plastic bag can prevent the entry of light and maintain a dark environment, in this condition, only respiration can be carried out and photosynthesis can not be carried out, and more carbon dioxide can be produced

Therefore, b

(1) The process in which green plants use light energy to convert carbon dioxide and water into organic matter that stores energy and release oxygen through chloroplasts, which is called photosynthesis; When device A is placed in the light for a few hours, the oxygen released by the plants during photosynthesis under the light is collected into the No. 1 test tube, and the oxygen has the property of combustion, so the wooden strip with sparks is extended into the No. 1 test tube, and the wooden strip will rekindle

2) Photosynthesis of plants can only be carried out under light, so sometimes in order to prevent plants from photosynthesizing, it is necessary to replace the plastic bag with black In the above experiment (1) and (2), two plastic bags, transparent and black, are used respectively to set up a control experiment, and the variable of this experiment is light

3) The process of water being lost from the plant to the outside of the plant through the stomata on the leaf epidermis in a gaseous state is called transpiration; During the experiment, the plants in the device are transpired, and the water lost is condensed into small water droplets on the inner wall of the glass cover

4) The process in which cells use oxygen to decompose organic matter into carbon dioxide and water, and release the energy stored in organic matter to supply the needs of life activities is called respiration; Placing device B in a dark place, the plant can not carry out photosynthesis, only respiration, consumes the oxygen in the plastic bag, and produces a large amount of carbon dioxide Therefore, the black plastic bag was selected for this experiment to shade the light, so as to avoid the plant from consuming carbon dioxide due to photosynthesis and affecting the experimental effect

So the answer is: (1) Oxygen

2) photosynthesis; controlled experiments; Light

3) transpiration; Catheter;

4) Black

2) The lime water in A remains clear, while the water in B becomes turbid, indicating that there is more carbon dioxide in B, which indicates that under the condition of lack of light, the plant mainly undergoes respiration. Breathe

3) There is no sunlight at night, plants mainly carry out respiration, and the dense forest has a high carbon dioxide content, which is not beneficial to human health

(1) Respiration refers to the process of decomposing organic matter into carbon dioxide and water with the participation of oxygen, and releasing energy at the same time The black plastic bag is not transparent to light, and plants cannot photosynthesize in a dark environment, only respiration Therefore, if A is a black plastic bag, and the valve at C is closed, the plant will respire to release carbon dioxide, and carbon dioxide will make the clarified lime water turbid Therefore, after a day and night, insert the B end of the glass catheter into the lime water in device C, and then open the valve, Squeezing the plastic bag by hand, the observed phenomenon is that the clarified lime water becomes cloudy, from which it can be concluded that the respiration of the plant produces carbon dioxide

2) The photosynthesis of plants is the process of using light energy in chloroplasts to synthesize carbon dioxide and water into organic matter, release oxygen, and at the same time convert light energy into chemical energy and store it in the synthesized organic matter If device B is placed in the sun, the students in the interest group will see that small bubbles will appear in the test tube, and when the gas exceeds the test tube L 2, take out the test tube for the experiment If the gas can rekindle the candle that is about to be extinguished, it can be concluded that the photosynthesis of green plants produces oxygen

3) Weak transpiration can also be carried out during the experiment, and the water in the plant body is emitted from the stomata of the leaf in the form of water vapor, so the water droplets on the inner wall of the plastic bag mainly come from the transpiration of the plant

Therefore, the answer is: (1) the clarified lime water becomes turbid; The respiration of plants produces carbon dioxide (2) the rekindling of candles that are about to be extinguished; Plant photosynthesis produces oxygen;

3) Transpiration

1) A and B two devices are coarse, one with a transparent plastic bag, the other with a black plastic bag, which is a set of control experiments with light as a variable, the purpose is to ** the condition of photosynthesis is light

2) Oxygen has the property of promoting combustion If the two devices A and B are placed in the light for 3-4 hours at the same time, the plants in the A device can see the light and carry out photosynthesis, so the carbon dioxide in the plastic Xizhen bag is reduced and the oxygen is increased; The plants in device B did not photosynthesize because they could not see light, but they respirated, so the oxygen in the plastic bag decreased and the carbon dioxide increased; Therefore, the gas in the plastic bag is collected through the A and B test tubes, and the test tube is taken out, and a wooden strip with sparks is stretched into the test tube, and the gas in the test tube A can be re-ignited with the martian wooden strips

3) The process of water being lost from the plant to the outside of the plant through the stomata on the leaf epidermis is called transpiration. During the experiment, the water vapor lost by the plants in the device during transpiration will condense on the inner wall of the plastic bag

So the answer is: (1) Light.

2) a 3) transpiration.

For photosynthesis in green plants, light must be met. Cover the plants with plastic bags, and there is still sunlight shining in, although the light is slightly weaker, but it is still there. With light, green plants can photosynthesize.

Hello, different plants have different needs for different colors in the light, some need red light, some need blue light, some need green light, generally speaking, transparent plastic bags and blue plastic bags and so on.

Because plastic bags can also transmit light, you try to cover them with a black plastic bag.

Because plastic bags are translucent, plants can photosynthesize when they have light.

As long as there is light, there can be photosynthesis. Even if there is no sunlight, it can be achieved by electric lights.

Because the plastic bag is transparent, light can penetrate it.

Impossible, impossible, there are no light plants in this, photosynthesis is impossible.

(1) chloroplasts and carbon dioxide; The green and non-green parts of leaf A are a set of experiments for the variable chloroplast (or the green part of leaf A and the green part of leaf B are a set of experiments for the variable carbon dioxide).

2) Formed by photosynthesis of the leaves before the experiment (or contained in the leaves before the experiment).

3) Before the experiment, place the experimental device in the dark for a day and night.

In order to exclude the influence of the original starch in the leaves on the experimental results, the experimental plants should be placed in a dark place for a day and night before the experiment, so that the original starch in the leaves can be transported away and exhausted

2) The organic matter produced by plants through photosynthesis is mainly starch, which has the characteristic of turning blue when exposed to iodine, so iodine solution is commonly used in experiments to test whether the leaves have photosynthesis: after the leaves are decolorized, iodine solution is added dropwise, and if it turns blue, it means that photosynthesis has been carried out and starch is produced;Otherwise, the leaves do not photosynthesize

3) After the iodine solution was added dropwise, the experimental phenomenon observed in this experiment was: the green part of leaf A turned blue, and the non-green part and the green part of leaf B did not change blue Comparing the experimental results of the green part of leaf A and the green part of leaf B, it can be concluded that the place of photosynthesis is chloroplast;Comparing the experimental results of the green part of leaf A and the green part of leaf B, it can be concluded that:

Carbon dioxide is the raw material for photosynthesis

4) The process of water being lost from the plant to the outside of the plant through the stomata on the leaf epidermis in a gaseous state is called transpirationThe water droplets that condensed on the transparent plastic bag during the experiment were formed by the water lost by the transpiration of the plants

So the answer is: (1) Put the plant in the dark for a day and night.

2) Iodine solution. 3) The place where green plants photosynthesize is chloroplasts;Carbon dioxide is the raw material for photosynthesis of green plants.

5) Transpiration.