How are dideoxynucleotides (ddNTPs) different from DNA nucleotides and why are ddNTPs needed in DNA sequencing

Aneuron is stimulated with an electric pulse. the action potential is detected at a point 3.70 cm down the axon 0.0052 s later.when the action potential is detected 7.20 cm from the point of stimulation, the time required is 0.0063 s. what is the speed of the electric pulse along the axon? (why are two measurements needed instead of only one? )

How do you date a sample of rock that you suspect as being one of the earliest on earth

Plz ! having a smooth seeds is the dominant trait. having wrinkled seeds is a recessive trait. the offspring of two plants with smooth seeds, a. must have smooth seeds. b. may have smooth or wrinkled seeds. c. must have wrinkled seeds. d. have a 25% change of having smooth seeds.