Both parents must be carriers, which means they have the heterozygous gene (one uppercase letter & one lower case letter). They will still carry that mutated gene (because they have a lower case letter), and their offspring will have a 25% chance of getting a recessive disorder. The percentage is low but still possible.
Answer:
a
Explanation:
This is owing to some nebulae (more than one nebula) come from the gas and dust thrown out by the explosion of a dying star, such as a supernova
