Tay-Sachs disease is caused by a mutation of one nucleotide for a protein that disrupts the activity of an enzyme in the brain. This leads to a toxic level of a substance to build up in neurons in the brain and spinal cord, leading to severe brain damage and eventually death. Why do you think that the change in one nucleotide can cause Tay-Sachs disease to be fatal, whereas the change in one nucleotide causes sickle cell disease, a disease in which a person can lead a functional life?

Grilled ham and cheese sandwich: caution: if you’re underaged then have a responsible adult supervising you to prevent any injuries.1. preheat a pan or griddle over medium heat. spread each bread slice with mustard — crust to crust is a must to get full coverage so that each bite is identical. if you don’t like mustard then use whatever else you like.2. use a trio of cheeses in a grilled cheese to achieve perfect harmony: 1 slice of american cheese for gooeyness, 1 slice of aged cheddar for sharpness and 1 slice of provolone or mozzarella for stringiness. if you don’t like these cheeses then use whatever else you like.3. ribbon your meat onto your sandwich to create dramatic height and a smoother bite down. don't just lay the meat flat — it makes for a flat sandwich.4. add anything else you'd like to the sandwich — (just make sure you season them with a bit of salt and 5. spread mayo on the outside of a grilled cheese before it goes into the pan or onto the griddle, which ensures that it will be perfectly golden brown every time.6. place on the griddle; dome your grilled cheese with a metal bowl to create a vortex of heat and ensure the cheese melts without over-toasting the exterior for a maximum of 3 minutes. flip, cover again and cook until the cheese is melted and the sandwiches are golden brown for a maximum of 3 minutes. hope this : )

True! is the answer hope this