Question 3
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
The Punnett square for this cross would be:
| | T | t |
|----|-----|-----|
| T | TT | Tt |
| t | Tt | tt |
From the Punnett square, we can see that there are 3 out of 4 possible combinations that would result in an offspring with triangular eyes (TT and Tt). Thus, the probability that an offspring would have triangular eyes is 3:4.
Therefore, the correct answer is d) 3:4.