A black short haired BBLl male is crossed with a black long

A black short haired (BBLl) male is crossed with a black long haired (Bbll) female. Determine the genotypic and phenotypic ratios of the offspring: Genotype ratio: Phenotype ratio: (b) A tabby, short haired male (TtbLl) is crossed with a blotched tabby, short haired (tbtbLI) female. Determine ratios of the offspring: Genotype ratio: Phenotype ratio:

Solution

Answer:

A)

                                     Male (Balck short haired ) BBSS          X        Female (black long haired ) bbss

                                                BS                                                                bs

                                                                  BbSs (Balck short hair, hybrid)                 -------------- F1 generation

                                The crossing of the two F1 generations takes place,   BbSs x     BbSs

                                  

BBSS, BBSs, BbSs: 9 Black short hair

BBss, Bbss    : 3     Black long

bbSS, bbSs   :    3 Brown short

bbss   :        1 brown long

Genotype ratio :1:2:2:4:1:2:1:2:1

Phentype ratio : 9:3:3:1

B)

A tabby short haired male (TtbLl)   X    A blotched tabby short haired female (tbtbLl)

Short haired male ( gametes) :    TL, TI, tbL, tbI.

Short haired female (female):    tbl and tbL.

                                

A tabby short haired male (TtbLL, TtbLl) : 3

A tabby long haired male (Ttbll)   :   1
A blotched tabby short haired female (tbtbLl, tbtbLL ) : 3

A blotched tabby long haired female ( tbtbll): 1

         

Phentype: 3:1:3:1

Genotype: 1(TtbLL):2(TtbLl):1(Ttbll): 2(tbtbLL):1(tbtbLl):1( tbtbll)

	BS	Bs	bS	bs
BS	BBSS	BBSs	BbSS	BbSs
Bs	BBSs	BBss	BbSs	Bbss
bS	BbSS	BbSs	bbSS	bbSs
bs	BbSs	Bbss	bbSs	bbss