Final answer:
To determine the outcome of a cross between a normal male and a short-haired female tribble with an X-linked recessive lethal allele, among the surviving F1 generation, half of the females will have short hair, and half will have normal hair, and all males will have normal hair since the lethal allele (X^nY) does not produce surviving males.
Step-by-step explanation:
To determine the outcome of a cross between a normal male (XY) and a short-haired female (XnX) tribble, assuming the n allele is an X-linked recessive lethal that results in short hair when heterozygous, we could set up a Punnett square:
- The normal male contributes either the X or the Y chromosome.
- The short-haired female, being heterozygous, can contribute either the normal X or the X with the n allele.
The cross would look like this:
XY (normal male) x XnX (short-haired female)
- Female offspring could either be XnX (short hair) or XX (normal hair).
- Male offspring could either be XY (normal hair) or XnY (lethal, hence would not survive).
Therefore, in the F1 generation, amongst the survivors, half the females will have short hair and half will have normal hair, and all males will have normal hair. The lethal allele in males (XnY) will result in no surviving males with the mutant allele.
Additionally, we must consider that X-linked recessive traits are more likely to appear in males because they only have one X chromosome, hence having only one copy of a recessive allele will express the trait.