After counting all the fields, everyone first focused on fields No. 10 and No. 11.
According to past thinking, the cross between tall-stemmed peas and short-stemmed peas should produce two peas with random height and shortness, or a compromise of medium-height peas. It may even be different due to different male and female stamens, but there is no One thought that these two hybrid fields were all, without exception, tall-stemmed peas.
This went against past knowledge and surprised the students.
Because from a common sense point of view, a child born to a couple with differences should be similar to one of them, or an intermediate type that intercepts the characteristics of the two. But Wandou’s performance is as if the child is exactly the same as one of the couple, and completely Unlike the other party, it is unimaginable.
"The blood factor I imagine can control the height of peas, but there are three hypotheses on how to control it."
Reiner explained as he started drawing a diagram on the paper.
"The first one is that the bloodline factors that control height take effect randomly, and the offspring will randomly get the bloodline factors of the previous generation. If this argument is true, then the experimental phenomenon should be..."
He did not finish speaking in a hurry, but looked at the three students, hoping that they could think independently.
"If that's the case, the result of crossing tall and short peas should be random tall or short peas."
Xia Luo answered first. She was very flexible in thinking and guessed the answer in no time.
"correct."
Reiner nodded to Charlotte, making the girl smile shyly.
"The second guess is that the bloodline factors that control height take effect at the same time. The offspring will get two bloodline factors, which will manifest themselves after fusion. If this guess is correct, what will happen?"
“Peas can come in tall stems, short stems, or medium height.”
Fina replied concisely and concisely that she had excellent grades. After Xia Luo's answer, she naturally understood Reiner's intention.
"That's right."
Reiner smiled. Although Fina didn't show much, Dana saw that the other two people had been praised. She felt a little unwilling and secretly clenched her fists.
"The third guess is that the offspring will receive two blood factors from the previous generation, but one of the blood factors is more powerful and completely suppresses the other. If this guess is true... . . ..”
Reiner looked at Dana, making the girl even more uneasy. She racked her brains and finally answered like a flash of inspiration.
"Then the peas might be all in one trait, all tall stems or all short stems."
After hearing Dana's answer, all the students looked at the two fields together. The tall peas were growing vigorously and producing full pods.
"So, the blood factor of tall stems is stronger than that of short stems, so that all peas become tall stems?"
Xia Luo murmured to herself, thoughtfully.
"At present, it can be said that it is correct. I call this more powerful blood factor the dominant blood factor, and the corresponding weak blood factor is called the recessive blood factor."
Reiner added that the control method he used is very common in biological experiments, and he took the opportunity to introduce it to his students.
"At the same time, I conducted two sets of experiments to eliminate the influence of gender by exchanging pistils and stamens of two kinds of peas. It can be seen that gender does not affect the traits of offspring unless there are special circumstances."
"Wait a minute, Mr. Reiner, there is another question in this hypothesis, that is, what did the blood factor of the tall stem do to the blood factor of the short stem? Is it completely swallowed, assimilated, or simply suppressed?"
Fina was the first to ask the question. She thought deeply, making Reiner nod slightly.
"Your thinking is correct, Fina. It seems that you have mastered how to think logically and consider every possibility of the problem."
Reiner's compliment made the girl with a calm face stunned for a moment, then she pursed her lips slightly and said nothing.
"We can now conduct designed experiments on this question. Thanks to hybridization, we have the finished product of a cross between tall and short peas. Our second planting will allow these peas to self-pollinate normally, so that We can see what the actual status of the blood factors of high-stem peas produced from hybrids with the same blood factors is."
With that said, Reiner turned his attention to the three students again.
"You can put forward some hypotheses and analyze the reasons at the same time, and then determine whether they are consistent based on experimental phenomena."
"If it is complete phagocytosis and assimilation, then the second-generation peas at this time will only have the blood factor of high-stem, and the third-generation peas should all be high-stem peas."
Charlotte said methodically, attracting a slightly envious look from Dana.
"If there is only simple suppression, then the second generation peas will have two blood factors, and the third generation peas produced by self-pollination... may have two traits: tall stems and short stems!"
After thinking for a while, Xia Luo completed her guess.
"Wait a minute, doesn't this mean that peas with short stems are produced despite being tall peas? Characteristics that did not exist in the previous generation appear in the next generation?"
Dana was a little surprised. If she had put it in the past, she would never have believed such a conclusion. But at this time, it was obtained through careful logical reasoning step by step, which is unconvincing.
"Although it is somewhat unbelievable, if short-stemmed plants really appeared in the third generation of peas, then this conclusion should be correct."
Fina nodded and looked at Reiner again.
"Mr. Reiner, there should be more than one similar trait. We can also use other characteristic comparisons to conduct verification experiments."
"Well, yes, actually, regarding this, I have obtained several kinds of seeds with different characteristics through crossbreeding. Our first round of planting is mainly to examine the transmission rules of traits, and the second round of planting will be Explore how blood factors affect traits."
In conclusion, Lehner felt that the results obtained from the first round of planting were enough to inspire these students to think independently.
After confirming the conditions of all fields, they sowed the classified hybrid seeds. About four days later, the conditions of the third generation of peas could be observed.
In fact, it can be logically deduced that if the dominant factors can completely assimilate the recessive factors, then the recessive factors should be extremely rare in nature, which is completely contrary to the rich and colorful nature that people can observe. It can be predicted to a certain extent here. The result of some experiments.
But Reiner knows that everything ultimately depends on practice.