Technology of storage and primary processing of agricultural products


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Bog'liq
Biologiya laboratoriya 2021

Examples for solving problems .
1.  The white color of the pumpkin fruit is represented by the dominant W gene, while the yellow color is represented by the Y gene. The W gene is an epistatic gene and does not cause the Y gene effect. Recessive alleles of these genes give a green color in the form of homozygotes.
A. When the two yellow-fruited pumpkins were mixed together, the yellow and green pumpkins were in a 3: I ratio. Identify the genotype of the parent forms. 
B. If digeterozygous white-fruited pumpkins are cross- bred, what is the separation at F 
A. Solution
Characters. Genes:
yellow y
white W; WY-:
green wwyy
According to the condition of the matter, in order for a yellow fruit to be formed, the genotype must have a dominant Y gene and a homozygous w gene. Therefore, we obtain the genotype of the mixed forms as follows:
P wwYy x wwYy
Gametes: wY, wy wY, wy
wwYY, wwYy, wwYy, wwyy
Thus, 3 parts yellow I part green pumpkins are formed. 
B. Solution:
We write the configuration scheme:
P WwYy x WwYy
WY, Wy, wY, wy WY , Wy, wY, wy
By placing gametes in the pannet cells , we create combinations of them.
Table 9


WY

Wy

wY

wy

WY

WWYY

WWYy

WwYy

WwYy

Wy

WWYy

WWyy

WwYy

Wwyy

wY

WwYY

WwYy

wwYY

wwYy

wy

WwYy

Wwyy

wwYy

wwyy

Thus, individuals with an epistatic dominant gene W in the genotype appear to be white. The development of pumpkin color in the F generation as a result of the epistatic effect of genes . 
We divide the zygotes in the cells into classes.
Genotype: Phenotype:
9-WY- white
3-Wy- white
3-wY- yellow
1-wy- green
Such yellow, but recessive genes will be green pumpkins.

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