Q1. The venom of many cobras contains a potent neurotoxin that binds to ligand-gated Na+ channels, causing them to open. Unlike ACh, that binds to and after that rapidly unbinds from ligand-gated Na+ channels, the neurotoxin tends to stay bound to ligand-gated Na+ channels. How does this neurotoxin affect the nervous system’s ability to stimulate skeletal muscle contraction? How does it affect the capability of skeletal muscle fibers to respond to stimulation?

Q2. Tay-Sachs disease is caused by loss-of-function mutations in a gene on chromosome 15 that encodes a lysosomal enzyme. It is inherited as an autosomal recessive condition. Among Ashkenazi Jews of Central European ancestry, about 1 in 3600 children is born with the disease. What fraction of individuals in this population are carriers?