An extraterrestrial planet has organisms that reproduce with DNA the same way as organisms on Earth. A common organism dwelling on this planet have eyes that are either triangular or round. Triangular eyes (T) are dominant to round eyes (t). A Punnett square should be made to predict the offspring of two of these extraterrestrials with the genotypes TT and Tt.
What is the probability that an offspring would have triangular eyes?
a
0:4
b
1:4
c
2:4
d
3:4
e
4:4
To create a Punnett square, we need to cross the genotypes of the two parents: TT and Tt.
T T
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T | TT | TT |
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t | Tt | Tt |
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From the Punnett square, we can see that there are four possible combinations of alleles: TT, TT, Tt, and Tt. Out of these four combinations, three have the genotype for triangular eyes (TT, TT, Tt). Therefore, the probability that an offspring would have triangular eyes is 3 out of 4, or 3:4.
The answer is (d) 3:4.