suppose a white , straight haired guinea pig mates with a brown ,curly haired animal.all five babies in their first litter have brown fur,but three are curly and two have straight hair.the second litter consists of six more brown offspring, where two are curly and four are straight haired. a. assuming curly is dominant to straight, what are the genotypes of the parents and the offspring? b. what is the probability of getting two female guinea pigs with straight hair in a row?

Dear Student,
Here is the answer to your query,
(a) Let us represent fur colour by 'B' (dominant) and 'b' (recessive) and hair by 'C' (curly) and 'c' (straight). 
It is given that a guinea pig with straight hair and white fur (bbcc) is crossed with a guinea pig with brown fur and curly hair (BBCC or BBCc). The F1 progeny had brown fur; hence, brown fur is dominant over white fur and curly hair is dominant over straight hair. 
Since, straight hair also appeared in the F1 progeny, the genotype of the parent with brown fur and curly hair can only be BBCc. The cross can be represented as follows;

Therefore, the genotypes of the parents are BBCc and bbcc and that of the offsprings are BbCc (brown fur, curly hair) and Bbcc (brown fur, straight hair). 

(b) The probability of having a female guinea pig with brown fur and straight hair is 50 %.

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