Sally is a carrier. If a person carries the genes, but doesn't have symptoms, they are known as carriers, because they have one infective allele and one normal allele. If you're familiar with genetics, she would be a heterozygote, and the disease was a somatic autosomal disease, with one dominant, passive allele, and one recessive, infective allele.
Answer: cell wall
Explanation:
https://micro.magnet.fsu.edu/cells/plants/cellwall.html
