Biological genetic problems Biologists come

I bought a batch of corn. I'm going to plant it. As a result, the first autumn I harvested much shorter than both the parent and the parent!

Oh, I know what the problem is: the father and mother are not homozygous (i.e., dominant heterozygous AA) so I harvested the dwarf corn. What to do?

Cross-breeding is the most basic method, I have to select the tall paternal and female parents every year for crossbreeding, and produce tall offspring, and then let the tall offspring cross each other. Okay, it's a lot purer, but at least four or five years have passed. (Waste of time).

So the simple way is to pick some plants that I think are purebred and tall, cultivate its pollen (because it is a unit body), and when the seedlings have grown, double the chromosomes with colchicine, wow! Purebred!

The offspring will not appear short!! (Fast speed, high efficiency, easy operation, low cost).

1) The gene frequency of a is .

The second question is based on the first question, because the gene frequencies of a in the population are , and a is also the gene frequencies of aa, aa, and aa in the offspring are , respectively.

The difference between the third question and the second question is that the second question is random mating between populations, and the third question is mating between the same genotype, so the mating between AA is AA... 1 4aa, 1 4aa, 1 2aa, only aa is produced between aa, and aa accounts for in the parent, so the aa of aa offspring accounts for 1 4 of the whole population, and the aa, aa, aa gene frequencies in (3) are ,

AA= is aa self-bred, is aa self-bred.

Harwin's law cannot be used for non-random mating.

Genes (genetic factors) are the material basis of heredity and are the specific nucleotide sequences on DNA or RNA molecules that have genetic information. Genes transmit information about the hail of the limb to the next generation through replication, so that the offspring will have traits similar to those experienced or from generation to generation.

Black dots indicate colonies.

The empty circle indicates the position of the control colony with B, i.e., there were no colonies in C where there were colonies in B.

What is the target gene, the title does not indicate that the "target gene" is an abstract thing, and there is no obstacle to the answer to this question.

For this problem, the introduction of the target gene will inactivate the resistance gene, and no longer have the corresponding resistance, which is an entry point for solving the problem.

The gene of interest is a foreign gene that is inserted into the plasmid vector.

The black dots in panel b represent colonies that are resistant to ampicillin, indicating that the ampicillin resistance gene is not disrupted in the plasmids of these colonies.

The black dots in panel C represent tetracycline-tolerant colonies, indicating that the tetracycline resistance gene is not disrupted in the plasmids of these colonies. Combined with the results of B, neither the ampicillin resistance gene nor the tetracycline resistance gene of these colonies were destroyed, indicating that no gene of interest was inserted into these plasmids.

The white dots in panel C represent colonies that are tolerant to ampicillin but not tetracycline, indicating that the tetracycline resistance gene is destroyed in the plasmids of these colonies. Combined with the results of B, the ampicillin resistance genes of the two colonies were intact, but the tetracycline resistance genes were destroyed, indicating that the tetracycline resistance genes of these plasmids were inserted into the genes of interest.