In given diagram which of the following combination showing recessive epistasis and supplimentary influence:-

	Recessive epistasis	Supplementary
(1)	K L O	F H N P
(2)	F N H P	K L O
(3)	F N H P	A B C D
(4)	K L O	A B C D

 

Dear student

Please refer the solution below for the said query


The correct option is (3).

• In recessive epistasis, the recessive epistatic gene masks the effects of the dominant gene.
• The inheritance of skin colour in mice is an example of recessive epistasis.
• In mice, the body colour of the wild type is agouti (greyish) and is controlled by the gene A which is hypostatic to the recessive gene c.
• The dominant gene C produces black mice in the presence of a.
• In the presence of C, A gives rise to agouti.
• Thus, CCaa will be black while ccAA will be albino.
• When black mice with genotype CCaa is crossed with albino mice ccAA, then the F1 progeny consists of Agouti mice (CcAa).
• The recessive gene c masks the expression of the dominant gene A. Thus, ccAA is albino. Here 4 albino are due to recessive epistasis.

 

Supplementary Genes are non- allelic genes that interact with each other to produce a new trait. But, when one gene is present alone, it produces its own trait. Here new trait produced is agouti when black and albino are crossed.

Hope this information clears your doubt about the topic.

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