When does the zygote begin to divide into a blastocyst?

Can someone check my answer 1.) at approximately what age does nerve conduction achieve maximum capacity? a. 5 (my guess) b. 10 c. 20 d. 30 2.) insulin is to glucagon as a. wet is to dry (my guess) b. walking is to running c. morning is to afternoon d. a key is to lock 8.) a neuron fiber that sends a signal from your hand to your brain is called a a. axon b. cell body c. mitochondrion d. dendrite (my guess) will give brainliest i'm deciding between two with each question, so if you could be original i would appreciate it. also, if you know the rest tell me so i can check my answers (i will make another post and give you 50 points)