Technology of storage and primary processing of agricultural products


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Biologiya laboratoriya 2021

Issues to be solved independently
1. A greenish-leafed female flower is pollinated with a yellowish-green leafy flower with the pollen of a green leafy cannabis plant. Gafur at the green and yellow-green dressing male plants. Gafur .
2.  In the Drosophila fruit fly, the gene that represents the red color of the eye - V - the gene that represents the white color - dominates over the v, which are located on the sex chromosomes. In the experiments, a red-eyed homozygous female Drosophila was mixed with a white-eyed male Drosophila. The male and female forms in the obtained F were interbred and 300 Drosophila were obtained in F . 1) How many of them are male and female? 2) How many male Drosophila were red-eyed and how many were white-eyed?
3.  In humans, color blindness is a recessive (d) disease that is passed down from generation to generation. People who normally distinguish color have the D gene. Both genes are located on the X chromosome. A heterozygous girl of normal color but with this sign married a colorblind man and had 8 children. 1) How many different gametes does a woman form? 2) How many newborns see normally? 3) How many boys have color blindness? How many girls have been diagnosed with color blindness?

15- LABORATORY WORK.

Topic: The transfer of genes from one generation to another. Crossingover.


The purpose of the work. It is the study of the causes of the transmission of certain traits in the body through generations.
The content of the work. The location of genes on the chromosome, the laws of their transmission to subsequent generations were first studied by the American scientist T.G. Morgan (1866-1945), who created the chromosome theory of heredity and was awarded the Nobel Prize for his services . Morgan and his students studied Mendel's laws on the basis of chromosomes in 1909-1911 and came to the conclusion that changes should be made to the law of independent distribution of characters . This is because genes do not pass from generation to generation in isolation, but in groups. To loot case hereditary trait genes to go to Morgan studied Drosophila (fruit fly). The Drosophila fly's body is black with a recessive gene-v, gray (normal color) with a dominant gene-V, rudimentary (short) wing with a recessive gene-v, long wing (normal wing) with a V gene. When gray-bodied, short-winged (VVvv) flies are confused with black-bodied, long-winged (bbVV) flies , all first-generation hybrids become gray-bodied long-winged (Vb Vv). Morgan mixed the digeterozygote with a first-generation (BbVv) hybrid with a recessive trait of homozygous (bbvv) female flies, i.e., carried out analytical crossbreeding . Due to the free distribution of genes in digeterozygous male (VbVv) flies , 4 different gametes were formed and the ratio of hybrids formed after their fusion with egg cells was as follows, 1: 1: 1: 1 .
BBvv x bbVV
Gametes Bv bV
BbVv
bbvv x BbVv
Gametes bv Bv, bV
Bbvv , bbVv
But at the end of such a mix, Morgan took only 2 varieties instead of 4 different hybrids, i.e. gray short- winged hybrids and black long-winged hybrids resembling parental characters . This hybrid characters - long, short wings, black and gray wings connected with the case traits, difficult transition .
Genes that colluded with the traits, to go to the same genes in one chromosome can be seen joylashgandagina. The B, c genes in the digeterozygous parent are located on one chromosome, and the B and B genes are located on the second chromosome. In this case, he receives two chromosomes with the B, c, and b, V genes from the father, and one chromosome with the b, c genes from the mother. Naturally, the four genes in this father (B, b, V, c) are passed on to subsequent generations because they are located on two chromosomes during cell division. Therefore, first-generation hybrids do not form 4 species, but only two different gametes. Such a combination of genes is called a complete combination.
The number of attached gene groups is determined by the number of chromosomes in the cell and is always equal to the number of chromosomes in the haploid set. For example, the haploid set of a Drosophila fly has 4 chromosomes, which means that the number of linked gene groups is 4. Combined gene groups differ from each other depending on the number of genes. If the size of a chromosome is large, will there be more genetic factors (genes), and if it is small, will there be fewer genes? The Drosophila fly has 3 large and one small chromosome. The 4 groups of genes attached to the Drosophila fly have also been very well studied, and the locations of all the genes in them and the origin of such a trait have been fully determined. Of the 39 pairs of chromosomes in chickens, only 8 have known gene groups.
Identifying combined gene groups is a very arduous task, requiring a lot of confusion and in-depth analysis of their results. In such crossbreeding, the transmission of traits to subsequent generations is determined on the basis of a gene whose location on the chromosome is clear.
This means that genes on a single chromosome are interconnected and pass on to the next generation along that chromosome. However, it is not always possible for genes to be attached to a single chromosome. Because the interconnection of genes can be disrupted. This situation was observed by Morgan in his following experiment. The gray-bodied, short-winged (VBvv) and black-bodied, long-winged (vvVV) flies were confused with recessively marked (vvvv) male flies by taking females (VvVv) instead of males from the first-generation hybrids. The hybrids formed as a result of such analytical mixing turned out to be four types instead of two, namely:
BBvv x bbVV
Gametes Bv bV
BbVv
BbVv x bbvv
Gametes BV, Bv, bV, bv bv
BbVv, Bbvv, bbVv, bbvv
1)  Gray, short-winged (Vbvv)
2)  Black-bodied, long-winged (bbVv)
3)  Gray-bodied, long-winged (VbVv)
4)  Black-bodied, short-winged (bbvv)
However, the ratio of the number of hybrids to each other did not correspond to the ratio (1: 1: 1: 1) observed in the independent distribution of genes. As a result of Morgan's experiment, gray-bodied - short-winged 8.5%, black-bodied long-winged 8.5%, gray-bodied long-winged 41.5% and black-bodied short-winged - 41.5%. The results of the experiment showed that in female hybrid flies obtained for crossbreeding, there was a breakdown of the attached gene groups, resulting in the emergence of a new set of genes, which led to the emergence of new traits. Therefore, in 17% (8.5% + 8.5%) hybrid flies, a new character that does not exist in the parent appears.
Disruption of the aggregation state of genes is due to crossover on chromosomes. In the diplonema of the first meiotic division period of cells, homologous (similar) chromosomes replace their homologous parts with each other. The exchange of similar parts on homologous chromosomes with each other is called crossover. This condition does not occur on all chromosomes. Homologous chromosomes that undergo confusion are called recombinants, and homologous chromosomes that do not occur are called recombinants. In our example above, the BV, bv gametes are recombinants i.e. crossover. Bv and bV gametes are noncombinants, ie gametes that do not crossover. If a gamete contains chromosomes that are confused, such a gamete is called a confused gamete and the organism formed from that gamete is called a confused organism. Only females of Drosophila flies have a chromosomal abnormality, which is not observed in males. Therefore, the above-mentioned digeterozygous female mosquito (VvVv) forms four different gametes instead of two different ones in male flies of the same genotype. Two of these gametes are confusing and two are confusing. In the above experiment, complete aggregation of genes is preserved in the first (Vbvv) and second (bbVv) states, while in the third (VbVv) and fourth (bbvv) states the complete synthesis of genes is disrupted as hybrids develop from confused gametes (BV, bv). will be.
Morgan found ways to determine the distance between genes based on chromosome confusion and gene aggregation. The study of chromosomes has shown that the confusion that occurs between them cannot occur in different parts of the chromosomes. Morgan took a value equal to one percent as a unit of confusion and called this value morganida. One percent of the confusion is equal to one morgan. For example, gray-bodied long-winged females (VbVv), black-bodied short-winged male flies (vvvv), and the confusion that occurs on the chromosomes of female flies when cross-bred produce a new set of genes (VV and BV) and result in 17% (8.5%) of hybrids. in two groups) a new character that does not resemble its parent appears. This means that the distance between the V and V genes is 17 morgans. It usually uses the following formula to determine the distance between genes:

X is the distance between morgan-sized genes;
a is the number of hybrids of the first group with chromosome confusion;
s is the number of hybrids of the second group with chromosome confusion;
n is the number of hybrids in the same experiment.
A yellow-bodied white-eyed digeterozygote (AaBb) was mixed with a female Drosophila fly and a black-bodied red-eyed recessive homozygote (aabb).
AaBb x aabb
Gametes Ab, aB, AB, ab ab
Aabb, aaBb, AaBb, aabb
A total of 50 hybrids were obtained: Of these
Yellow-bodied red-eyed (Aabb) - 0.3
Black-bodied white-eyed (aaBb) - 0.3
Yellow-bodied white-eyed (AaBb) - 24.7
Black-eyed red-eyed (aabb) - 24.7
To find the morgan in this example, we first identify the groups in which the confusion occurred, then put it in the formula to find how many morganids it is equal to.

The morganide merging of genes A and B is 1.2.
A diagram depicting the relative location of genes on a single chromosome relative to each other is called a genetic map. Genetic mapping is a very difficult task, for which the experimenter must be aware of several mutant genes that occur in the same organism, and have to do a lot of hybridization with them. Only in very well-studied organisms is their genetic map complete (Drosophila mosquito, corn, neurospore, etc.).
The genetic map is created separately for each of the combined gene groups. The names of the genes on each chromosome, as well as the distance between them, are marked in the organelles and the location of the centromeres.
Issues to be solved independently
1.  After reading the topic in full, write down what you understand and the confusion diagrams in your lab notebook.
2.  The two lines of corn are intertwined. A total of 1,000 grains were obtained from them
482 color smooth - (CcSs)
482 are colorless - (ccss)
18 color twists - (Ccss)
18 colorless smooth - (ccSs)
Color smooth dominant, colorless twisted recessive character. Identify the morgan between color and smoothness?
3.  One of the homologous chromosomes contains genes A and B, and the other contains genes a and B. These plants produce several different crossingovers and crossovers gametes.

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