Question 17 of 20 >
Platyfish with spots have an X-linked gene that produces the spots. All platyfish have an autosomal repressor that inhibits
the expression of the spot-producing gene. The closely related swordtail lacks both the spot-producing gene and the
repressor. In backcrosses between the two species, some hybrids receive the spot-producing gene, but not the repressor.
These individuals can develop malignant tumors, because the expression of the spot-producing gene is not properly
regulated. What should we expect for hybrids that lack both the spot-producing gene and the repressor?
Males should develop tumors and have low fitness, while females should have high fitness.
Both females and males should develop tumors and have low fitness.
Half the females and half the males should develop tumors and have low fitness, while the rest should have high fitness.
Females should develop tumors and have low fitness, while males should have high fitness.
Both the females and the males should have high fitness.