High School Biology is about the laws of genes, the laws of genetic equilibrium in high school biolo

AABB, black female A B x brown AAB , to get AAB, obviously black female dog also provides AB

bb：bb：bb=1：

2:1, so the probability of the offspring of the black hair female dog is 2 3 If the puppy is a red-haired male, then the black hair female dog must provide a and b, so the probability of providing a is 1 2, b is 2 3x1 2 = 1 3, ab = 1 6

It has to be male, so it has to be multiplied by 1 2

So 1 12

First of all, the genotype of the yellow dog of the offspring is AAB, which is determined, and the black dog has AAB and AAB two genotypes, and the ratio of these two genotypes can be judged by the parental gene to be 1:2, but if there is a red dog, then only AABB This kind of black dog can only be used, accounting for 2 3 of the black dog, so that 2 3 1 2 1 2 is a red dog, and then multiply 1 2 for the male, which is one twelfth.

If you have any questions, please feel free to ask, if there is no problem, thank you.

AABB (black male) * AABB (brown female).

There are two cases, (the first one) 1 3 chance is that AAB*AAB gets the own red that contains the BB gene.

The second kind) 2 3 probability is AABB * AABB to get A-BB, because it is impossible to produce AABB situation, so it can only be AAB: 2 3 (AABB probability) * 1 2 (probability of getting AA) * 1 2 (probability of getting BB) * 1 2 (probability of getting a male dog) = 1 12

The law of genetic equilibrium is generally referred to as the Hardy-Weinberg law. The Hardy-Wemberland law states that in an ideal state, the frequencies of alleles and the genotype frequencies of alleles are stable in heredity, that is, the genetic balance is maintained. Hardy-Weinberg's Law of EquilibriumFor a population that is large and randomly mated early, gene frequencies and genotype frequencies remain constant in the absence of migration, mutation, and selection.

Applicable conditions: 1. The population must not be large enough;

2. Random mating between individuals in the population;

3. No mutations;

4. There is no choice;

5. No migration;

6. No genetic drift.

(11 points) (1) AABB, AABB (2 points) (2) Comply (1 point).

3) Synthesis of enzymes to control metabolic processes (2 points) (4) Purple: blue: white = 3:3:2 (2 points).

5) Genetics ** is as follows (2 points each for parents and offspring, 4 points in total).

(1) The genotypes of plants A and B in Figure A are ABB and AABB, respectively. If the F2 blue flower plant in Figure A is self-crossed, the phenotype and ratio of its progeny are as follows: blue flower: white flower = 5:1.

From F2, it can be seen that this is a variant of 9:3:3:1, so it is inferred that the parental genotypes A and B are AAB and AABB respectively.

When gene A exists, gene B does not exist, that is, the genotype is "A BB", the flower color is blue, according to the FI genotype ABB, the F2 generation blue plant genotype is AAB and AABB, and the ratio is 1:2, and the representative type after inbreeding has blue flowers and white flowers and the ratio is: 5:1

White pigment is intrinsic, the phenotype of plants without gene A is white flowers, blue flowers with gene A without gene B, and purple flowers with both genes A and gene B. This is typical of Mendelian heredity's laws of 9:3:

3:1, f2 can also be written as purple flower: blue flower:

White flowers: white flowers = 9:3:

3:1, corresponding genotype is (aabb, aabb, aabb, aabb) :(aabb, aabb):

aabb、aabb）：（aabb）。

1.In the law of segregation, when F1(dd) produces gametes, due to the separation of alleles, two equal numbers of female gametes (D, D) and two equal numbers of male gametes (D, D) are formed, and the male and female gametes are randomly combined to form 1 4dd, 1 4dd, 1 4dd, 1 4dd, and 1 4dd, and due to the masking effect of dominant genes on recessive genes, 1 4dd and 2 4dd are manifested as dominant traits, so the offspring have a trait segregation ratio of "3 1". The main reasons for its formation are allele segregation and the masking effect of dominant genes on recessive genes (complete dominance).

The segregation ratio of traits is the result of the combined effect of allele segregation and complete dominance.

2.Reasons for the ratio of traits in the law of free combination.

The law of free combination is the expansion and extension of the law of segregation in terms of "quantity", and the reason for the formation of the segregation ratio includes all the reasons for the formation of the segregation ratio in the segregation law, and there is also a reason for the free combination of non-allelic genes on non-homologous chromosomes.

3.Causes of the ratio of trait segregation in the law of linkage and exchange.

The law of separation is also the basis of the law of chain exchange, and the causes of the separation ratio include all the reasons that form the separation ratio in the law of separation. When the law of free combination f1 produces gametes, the ratio of various types of gametes is the same; However, when F1 produces gametes in the law of linkage exchange, the type and exchange rate of exchange sex mother cells are important reasons for the formation of the segregation ratio in the law of chain exchange, because some sex mother cells do not exchange and some exchange are exchanged, and the exchange includes single exchange and double exchange.

In order to be able to answer this question correctly, it is necessary to understand the conceptual connotation of gene frequency in Chapter 7 [Modern Biological Evolutionary Theory] of Biology Compulsory 2 "Heredity and Evolution", and at the same time, you should know the application of the law of genetic equilibrium in order to answer this question more easily.

Solution: From the description of the title, it can be seen that the genetic disease is a recessive genetic disease, and 1 out of 10,000 people have this disease, so it can be known that the genotype of patients with recessive gene inheritance is AA, and their proportion in the whole population is AA 1 10000, that is, it is equivalent to.

aa a a a a 2 1 10000 so the gene frequency of a a 1 100

According to the law of genetic equilibrium, we can see that a a 1 so the gene frequency of a a 99 100

Once the gene frequencies of a and a are known, the solution can be analyzed.

1) The proportions of each genotype in these 10,000 people are:

The genotype is AA 99 100 99 100 9801 10000

The genotype is AA 2 99 100 1 100 198 10000

The genotype is AA 1 100 1 100 1 10000

2) The probability of a carrying male marrying a female and the offspring getting sick is:

From the analysis of the theme, it can be seen that the genotype carrying the male must be AA, while the female genotype is possible for all three genotypes, that is, there are the following three genetic combinations:

aa aa, this genetic combination produces offspring that will not have the disease.

aa aa , the probability of this genetic combination producing offspring with a diseased person is 1 4 1

aa aa, the probability of this genetic combination producing offspring with a diseased person is 1 2 1

Based on the above analysis, it can be concluded that the probability of a carrying male marrying a female and the offspring will be diseased

3) If a carrying male marries a normal female, the probability of the offspring suffering from the disease is:

From the analysis of the title, it can be seen that the genotype of carrying males must be AA, and the genotype of normal females has two genotypes, namely AA and AA, and only after marriage with a woman whose genotype is AA can the disease occur, and the concept of offspring disease is 1 4, and because the phenotypic normal female, the probability that the individual with the genotype AA accounts for all normal females is:

aa ÷ aa＋aa ) 2/101

Based on the above analysis, it can be seen that if a carrying male marries a normal female, the probability of offspring suffering from the disease is:

aa = 1 10000, i.e. the gene frequency of a is 1 100 and the gene frequency of a is 99 100

The male carrier AA probability is 2*1 100*99 100=198 10000

Females normally have AA or AA probability is squared, 198 10,000 offspring are diseased, that is only possible if both men and women are carriers, that is, 1 4 * male and female gametes each account for 1 100 because the gametes produced by males are all male gametes and females are all female gametes The gene frequencies are the same The probability of producing a is The probability of producing a is The probability of producing a is.