Why would someone with a mutation in the brca1 gene have a higher risk of developing cancer earlier in life than someone without a mutation in the brca1 gene?

Mutations to either breast cancer gene BRCA1 significantly increase your risk of developing breast cancer and ovarian cancer when compared with the cancer risk of a woman without a BRCA gene mutation. Men with certain inherited BRCA gene mutations also face an increased risk of breast cancer.

what statement best describes the difference between the sympathetic and parasympathetic nervous systems?

the sympathetic nervous system prepares the body for intense physical activity and is often referred to as the fight-or-flight response. the parasympathetic nervous system has almost the exact opposite effect and relaxes the body and inhibits or slows many high energy functions.