Sprouting of soybean seeds

In the summer, I did the experiment of "sprouting of soybean seeds". I prepared clear plastic cups, soil, paper towels and soybean seeds. Then lay the paper towel around the cup, and put a large part of the soil in the cup, then I put 5 seeds in the middle of the cup and paper towel. Finally, I crumbled a small portion of the remaining dirt into the cup (the seeds were about a centimeter deep from the surface) and sprinkled some water so that the paper towel was completely wet. This way the seeds were planted.

After a day. I came to the windowsill to observe the planted seeds. I noticed that the color of the seeds changed a little. Originally, the color of the seeds was yellow, but after a day and a night, the appearance of the seeds was a little lighter and felt a little transparent, the seeds looked especially full, and the seed coat was a little cracked.

Two more days passed. I came back to the windowsill to observe the seeds. I glanced into the cup. To my surprise, I realized that the seeds had sprouted. The shell on the outside of the seed cracked. From inside, a shoot emerged, the color of the shoot was yellowish, slightly greenish. The tip of the shoot is pointed, and this is the bud. The bud was changing direction and growing downwards. A condensed question appeared in my mind: why does the seed's bud grow downward? Wouldn't that prevent it from burrowing out of the soil?

After another day, I once again came to the window sill to observe the seeds. Through my careful observation. The seeds were very different from when they were sprouting. The shell of the seed had just cracked when it was sprouting, but now most of it had fallen off. The leaves in the seeds had left their original position and were closer to the surface, and two had burrowed out of the soil, and what had been closed together was now unfolded, with a small bud in the center. I also noticed that each bud had two leaves, one in the middle of a thin vine. Like the shape of a love heart. The lower part of the leaf is a little curved, like an old man on a pack.

Five days later, when I came to the window sill again, there were many young green bean seedlings in the cup. Some had two leaves, some already had four, though the two in the center were smaller. I also noticed that its leaves were all in pairs of two by two.

Now I know why the buds of this seed grow downward. That's because it's not a bud that just grows, it's a root, so it has to grow downward.

When I came to the windowsill to observe again, I was sad because I didn't take good care of it, and the soybeans I planted somehow fell to the ground and died. Although all the seedlings died, but through this experiment I also got a lot of knowledge: soybean seeds by the seed coat, embryo, cotyledons, embryo can be divided into radicle and germ, radicle developed into soybean roots, germ developed into soybean stems and leaves, germination is the first to grow out of the root, soybean leaves are two pieces of two pieces of the opposite.

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I found a list of the soybean seed germination process (the dates don't match, but you can change them):

Sowing date: February 12

Skin splitting: February 15, when I was pouring water, I saw the seed skin splitting open and saw a white bean.

Growth of radicle: Feb. 18, I saw the radicle growing when I started pouring water, and the radicle was growing downward as if it was absorbing water.

Germs: On February 19th, I saw germs growing while I was observing. The sharp white germ was growing upwards, absorbing water and carbon dioxide from the air, just like a human being absorbs oxygen.

Root growth: On February 21, I saw the radicle begin to elongate while I was observing. The embryonic root elongated one or two centimeters and grew into the root of a bean sprout.

Embryo growth: On Feb. 22, while pouring water, I accidentally noticed that the embryo was starting to elongate, burrowing out of the soil and resembling a comma on top of the soil.

Cotyledon emergence: The cotyledons are a little white and a little yellow, and they look great.

Growing real leaves: On Feb. 26, I went back and saw that the comma shape of the germ was gone and it was growing into leaves and stems, the leaves were green and tender and beautiful, and underneath the leaves were two cotyledons that were a little yellow.

Shriveled cotyledons: On February 29, I went to pour water again and saw two cotyledons deflated, very yellow and shriveled.

Otherwise: March 2, soybean sprouts are now growing into a seedling, with four leaves, a stem of about five centimeters, and a very long seedling root of three or four centimeters. The seedlings are green and thick.