A transmembrane protein has its N-terminus in the lumen of the ER, its C-terminus in the cytoplasm, and it spans the membrane five times. What are all the signals that this protein displayed, including any that may have been cleaved? (In the following options "STS" stands for "stop transfer sequence")

Acar company is testing seatbelts using crash test dummies. the company finds that when cars come to a sudden stop, the crash test dummies' bodies continue to move forward. the seat belt keeps the crash test dummies from hitting the back of the seat in front of them. why do the crash test dummies' bodies continue to move forward even though the car stopped? a. the friction opposing their bodies' movement keeps them in motion. b. the inertia of their bodies keeps them in motion. c. the forward acceleration of the car keeps them in motion. d. the gravity pulling on the car keeps them in motion.

Is there any species that went extinct in recent years due to natural causes (not caused by human interaction). if so, what caused it?

Ihave no idea how to solve these. plus there's another question that is 2) a 10 kilogram meteorite is collected in space and brought back to earth. it is composed of 1.25 kg of uranium-238 and 8.75 kg of lead-206. how many u-238 half lives have passed? what is the approximate age of the meteorite?