The presence of gill-like slits in a human embryo is considered to be evidence for the

A. theory that fish and mammals have a common ancestry

B. theory that the first organisms on Earth were
heterotrophs

C. close relationship between fish and mammaliap
reproductive patterns

D. close relationship between humans and annelids

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? )

Which of the following conclusions can be drawn

How does the study of genetic disorders such as pku biologists understand normal alleles?