The question of heredity needs to be addressed urgently

1.Hypothesis: The presence of dimples is dominant A control.

Mother A then mother has dimples, father Aa then father does not have dimples.

Xiao Wang A, then Xiao Wang has dimples.

2.Hypothesis: The presence of dimples is recessive A control.

Mother aa, then mother has dimples, father aa then father does not have dimples.

Xiao Wang aa, then Xiao Wang has dimples.

Both of these assumptions are the same as those described in the title.

Indicates that the genes that cannot be judged to dimple are not necessarily controlled by dominant genes.

I suggest that you still understand the definition of dominant and recessive genes, and then you will understand the role of genes.

According to the conditions given in the title, it is impossible to infer whether Xiao Wang's dimple is recessive or dominant, and it is not said whether the dimple is hereditary, if it is inherited, the brothers upstairs have already said very clearly, and there are more than these two situations, so the meaning of this standard answer is obvious, that is, it cannot be inferred that the gene that controls dimples is a dominant gene. (If there are too many assumptions, there is no answer at all).

The answer is incorrect. 1.Hypothesis: The presence of dimples is dominant A control.

Mother A Father AA

Xiao Wang A (regardless of whether the mother has recessive A in the gene, Xiao Wang will have dimples) 2Hypothesis: The presence of dimples is recessive A control.

Mother AA Father AA (or father AA).

Xiao Wang AA, at this time Xiao Wang has no dimples (or Xiao Wang AA, at this time Xiao Wang has dimples) To sum up: there are dimples for the dominant A control.

Having dimples is dominant, mother A is dominant, and Xiao Wang has dimples.

Hypothesis 2 has dimples that are controlled by recessive A, and the father has dimples that are dominant, but some genes are not necessarily controlled by dominant genes, so it is possible that dimples in 2 are controlled by recessive A.

It is recommended that you clarify the definitions of dominant and recessive genes.

1.Mother: Gene with dimples + any gene Father: Gene without dimples + gene without dimples.

Then you draw a gene ** by yourself, and there will be an answer to Xiao Wang: a gene with dimples + any gene.

2.Mother: Gene with dimples + Gene with dimple Father: Gene without dimple + Gene with dimple Then Xiao Wang: Gene with dimple + Gene with dimple.

There are more than these two cases, so the implication of this standard answer is obvious: it cannot be inferred that the gene that controls dimples is the dominant gene.

This answer tells you that the genes for dimples are not necessarily controlled by dominant genes.

The standard answer to this is that there are two conditions that control the gene that has dimple trait.

The question is whether it can be inferred that the gene that controls dimples is the dominant gene, or whether it can be inferred that the dimple is the dominant trait.

It's all wrong, speechless Because according to the assumption, it can be concluded that when the father is aa and the mother is aa, there is only one kind of son Xiao Wang born, so there are 4 situations.

The answer to this question is a bit one-sided, right? Even companion genetics was not considered, and Xiao Wang's gender was not said.

Attention conditions:1Only one pair of alleles per pair of chromosomes is considered;

2.All from a single parental breed.

Analysis: There are 8 chromosomes in the fertilized egg of Drosophila, 4 from the female parent and 4 from the paternal parent, when the fertilized egg becomes an adult, and the adult produces gametes", the useful information is: 8 chromosomes (4 pairs) produce gametes. Everything else is nonsense (interfering with information).

A pair of alleles on a pair of chromosomes, the total number of gametes containing all gametes from one parent is 1 2 (aa and aa);

Then the total number of gametes produced by 4 pairs of chromosomes all from one parent is (1 2) to the fourth power, i.e. 1 16. Complete.

It is possible to know that the causative gene is on x and is recessive.

Then the genotype of the normal couple is x big a y x big ax small a, so the genotype of the offspring is x small ay, and the probability is 1 in 4.

Because the incidence rate in women is 4 in 10,000, the probability of X small A in women is 2% (2% squared is 4 in 10,000), so the probability of offspring suffering from the disease is 2% times 1 in 4 equals 1 200 choose C

Fox odor is generally genetically generated, not only dominantly inherited, but also from the perspective of the yellow race, it should belong to companion inheritance. The genetic factor of fox odor should be on the sex chromosome, that is, on the X chromosome of the sex chromosome XY. Therefore, fox odor is inherited by x dominant, and there are generally the following situations:

1) Both parents have fox odor and the mother is homozygous (if the dominant gene that controls fox odor is represented by a, then the normal gene is a), then the offspring, whether male or female, have a prevalence of 100%.

Parent xay xaxa

Child xaxa xay

2) If both parents have fox odor and the mother is heterozygous, the prevalence rate of offspring is 50% for females, 100% for females and 50% for males, and those who are not diseased do not carry pathogenic genes.

Parent xay xaxa

Child xaxa xaxa xay xay

3) If the father has fox odor and the mother is normal, the offspring of females will not be diseased, and women will carry 50% of pathogenic genes, and males will not be diseased and do not carry.

Parent xay xaxa

Child xaxa xay

4) If the father has no fox odor and the mother is homozygous for fox odor, the offspring will not be diseased in females, 100% of females carry disease-causing genes, and 100% of males will be diseased.

Parent xay xaxa

Child xaxa xay

5) If the father has no fox odor and the mother has a fox odor heterozygous, the offspring will not be diseased in females, carrying 50% of genes and 50% in males.

Parent xay xaxa

Child xaxa xaxa xay xay

Parent xay xaxa

Child xaxa xay

The couple gave birth to a child together, and according to real-life statistics, about 30% of the child's genes are inherited from his parents, and 70% is acquired, so Guan Jian still cares about how to train him to become a talent.

In the mid-40s of the 0th century, scientists experimentally proved that DNA is genetic material.

In 1953, Watson and Crick discovered that the structure of DNA is a double helix. In 1962, they were awarded the Nobel Prize in Biology and Medicine for revealing the structure of DNA.

In the early 60s of the 20th century, scientists decoded the genetic code – how DNA encodes the amino acids that make up proteins, how they are converted into proteins by cells, how DNA replicates itself, and how replication errors, mutations, and sexual recombinations cause variations.

Pprraa and Pprraa were crossed, F1 was Pprraa, and the proportion of wheat obtained by F1 inbred was 3 4 times 3 4 times 3 4 by 3 4 4, that is, 27 64, and the ratio of homozygous Mao Ying, rust resistance, and no mangs (Pprraa) was 1 4 times 1 4 times 1 4, that is, 1 64, so the proportion of homozygous Mao Ying, rust resistance, and no mangs accounted for the phenotype of Mao Ying, rust resistance, and no mangs was 1 27, so the ratio of Mao Ying, rust resistance, and no mangs ( pprraa), at least 10 wheat, p-r-a-free (p-r-a-) wheat with the phenotype should be selected in the F2 population, and the expression type should be at least 1 divided by 1 27, that is, 270 plants.

There are better formulas:

Creating something out of nothing is hidden, and giving birth to a girl is often hidden".It means that the disease-free parents give birth to a sick child, and this genetic disease is a recessive genetic disease; If a diseased daughter is born, the disorder is autosomal recessive.

There is no dominance in the middle of life, and the disease of the birth of a girl is often obvious".It means that the sick parents give birth to a disease-free child, and this genetic disease is a dominant genetic disease; If a disease-free daughter is born, the genetic disorder is autosomal dominant.

Through these two formulas, the autosomal genetic disease can be eliminated.

As for companion inheritance, there is also a formula:

In the case of recessive inheritance, "the mother and the child will be sick, and the female and the father will be sick".The reason is that the mother has the disease, and both of her X chromosomes carry a recessive pathogenic gene, and there must be a recessive pathogenic gene that is passed on to her son (genotype XY) along with an X chromosome, and the son's Y chromosome has no relative equivalent action, and a recessive pathogenic gene causes the male to manifest the disease. In the same way, when a daughter is sick, both of her X chromosomes carry a recessive pathogenic gene, and there must be a recessive pathogenic gene that was passed on to her by her father (genotype XY) along with an X chromosome.

In general, in the pedigree with X recessive, if a woman has a disease with X recessive, her father and her son should be the patients. And in the pedigree with x recessive, the incidence is more common in males than females.

In the dominant inheritance with x, "the mother will be sick, and the father and daughter will be sick".The reason is similar, in the pedigree with X dominant, if a man suffers from a sex X dominant genetic disease, his mother and his daughter should be the patient. And in pedigrees with x-dominant inheritance, the incidence is more common in females than males.

In Y-chromosome genetic diseases, it is manifested as a disease that only occurs in males, and it is passed from father to son, from child to grandchild, and there is no end of children and grandchildren.