Answer: Mutation can affect an organism by resulting to a change in the number and structure of chromosomes (chromosomal mutation). A typical example of this type of mutation is Down's syndrome where the individual contains 47 instead of 46 chromosomes.
Mutation can also result to a change in the nucleotide sequence of the DNA molecule in a particular region of a chromosome(Gene mutation) an example of genetic mutation is sickle cell anemia
The answer is rr because if it were "Rr" it would be round. Dominant always exceeds the recessive. so if both traits were recessive, it would be recessive. so "rr" is your answer