On an extraterrestrial planet, which had organisms that reproduced with DNA the same way that organisms on Earth do, green little organisms have eyes that are triangular or round shaped. Triangular eyes are dominant to round eyes. A cross was performed between two of these extraterrestrials with the genotypes IT and tt. Predict the probability that an offspring would have round eyes.

Question

On an extraterrestrial planet, which had organisms that reproduced with DNA the same way that organisms on Earth do, green little organisms have eyes that are triangular or round shaped. Triangular eyes are dominant to round eyes. A cross was performed between two of these extraterrestrials with the genotypes IT and tt. Predict the probability that an offspring would have round eyes.

2:4
1:4
4:4
0:4

choose the best answer

Answer 1

The best answer is 0:4.

The genotype "IT" represents a heterozygous organism with the dominant Triangular eye allele ("I") and the recessive round eye allele ("t"). The genotype "tt" represents a homozygous recessive organism with round eyes.

When these two organisms are crossed, their possible offspring genotypes would be IT, It, It, and tt. Out of these four possible genotypes, none of them have the genotype for round eyes (tt). Therefore, the probability that an offspring would have round eyes would be 0 out of 4.