Can anyone help me explain linkage genetics, thank you 30

This is explained very clearly.

For the sake of simplicity and genotype, the wx gene is abbreviated as w and the sh gene is abbreviated as s

It must be linked, because the trait ratio does not conform to the measured cross ratio (i.e., the ratio for all traits is 1).

CCWWSS CCWWSS, according to the two traits with the largest proportion, colorless waxy fullness (2349, genotype CCWWSS) and colored non-waxy wrinkle (2216ccWWSS), the heterozygous genes on two pairs of chromosomes were cws cws, respectively, and then the alcohol and parental genotypes: ccwwss ccwwss were introduced

Gene sequencing is determined first. The two pairs with the smallest proportion were double-exchanged, so the gene sequence was determined as: CSW CSW

Now let's get into the key to this question).

First, the traits were divided into four groups according to the proportional size, two by two, and the heterozygous parental gamete genes were written

CSW CSW (parental type) 4565 CSW CSW (double exchange) 35

The order exchange value is then calculated.

Observe the situation of genes c and s together when calculating (c&s), and calculate the exchange rate:

In the same way, the exchange rate of (s&w) is recalculated: (35+1925) 6708=

Calculate the theoretical double exchange rate:

Actual double swap rate: (20+15) 6708=

Interference rate (degree of interference) =

Yes, after you finish it,,, this kind of question will not be read on the Internet, it's not very difficult but it's too troublesome, so you have to calculate it carefully, in fact, it's relatively basic.

The answer is D, just draw two pictures for you.

1.If you want to determine the gene sequence and distance, you need to do 6 two-point tests, as shown in the figure below, the six points in the upper triangle or the lower triangle are the combination of six two-point measurements.

2.If you consider a three-point test, see the figure below, the blue is the three-point test and the yellow two-point test, so you need a two-point test and a three-point test on both sides.

The first time I encountered this type of genetic linkage question, from a practical point of view, this question will not be applied to the construction of genetic linkage diagram.

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See clearly, it is also according to the 4 sensitivity that the Chinese call it a hundred feet as the shape, and now the theater viewing buildings are all designed in this way, you along. The central axis walks into all the buildings of the Forbidden City, implements this system, and opens a shop, we eat 35 meters from the Chinese line.

See it's human. Just went up to the ontological argument. It represents the first and then the next to catch up.

The power and status of this ** repaired the largest palace in the country at that time, and he was very proud of the casual cultivation who wanted to climb up to take a break. He told a series of truths. No, you can't.

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ab linkage rate 10% bc20% this you know then ab10% ab=ab=(100%-10%-10%) 2=40% the same way bc=10% bc=bc=40% coincidence coefficient = actual double exchange.

Theoretical double exchange Theoretical double exchange = 10% * 20% = 2% So the actual double exchange = may produce parental type a b c 1/200% minus the others a b c single exchange a b c 5% half ab exchange rate a b c 5% single exchange a b c 10% half bc exchange rate a b c 10% double exchange a b c 10% double exchange a b c half double exchange rate a b c this is written very clearly If you don't understand it, go read the book Explain that you don't understand the basic concepts The second question is the reverse of the first question, It's just asking you how much half of your parents are, or something like that, and you can do the math yourself, according to my list. Typing is so tiring to ask for adoption.

The study of linkage inheritance confirms that genes are arranged in a certain order and distance on chromosomes, and through the exchange of genes, the content of parental genetic material recombination is enriched, which creates conditions for selection in the process of biological evolution. In cross-breeding work, if the genes involved have a linkage inheritance, the frequency of occurrence of recombination genotypes can be based on the magnitude of their exchange values. In order to make the hybrid offspring appear more ideal types, it is necessary to determine the planting scale of the hybrid population according to the size of the recombination rate.

It is also possible to use the linkage of traits to select or eliminate other traits according to the performance of one trait.

Linkage inheritance: two or more traits of the original parent are often linked to F2 inheritance.

Linkage: A phenomenon in which several non-allelic genes are located on the same chromosome and are inherited by linkage.

Fully linked: located on homologous chromosomes.

Swapping between non-sister chromatids cannot occur between upper non-alleles, and F1 produces only two parental gametes.

The phenotypes of the inbred or tested offspring are all parental combinations.

Incomplete linkage (partial linkage): F1 can produce a variety of gametes, and the offspring appear a combination of new traits, but the number of new combinations is less than theoretical. Complete linkage of non-allelic genes is rare and is usually incomplete.

What is the concept of linkage heredity.

After Mendel's genetic law was rediscovered in 1900, people used more inflamed animals and plants as materials to carry out hybrid experiments, which belonged to the inheritance of two pairs of traits, some of which conformed to the law of independent distribution, and some did not. Morgan used Drosophila as the test material for his research, and finally confirmed that some examples of so-called non-independent inheritance were not in fact independent inheritance, but belonged to another type of inheritance, that is, linkage inheritance. Thus, after Mendel's two laws of inheritance, linkage inheritance became the third law of inheritance in genetics.

The so-called law of linkage inheritance is that two traits originally possessed by the same parent often have a tendency to be inherited together in F2, and this phenomenon is called linkage inheritance.

The discovery of the law of linkage inheritance confirms that chromosomes are the carriers of genes that control traits. The assay by exchange further proves that the genes have a certain distance on the chromosome, arranged in a straight line. This laid a solid scientific foundation for the development of genetics.