Opening of a flatworm used for collection of food and expulsion of waste

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? )

The cellular plasma membrane is selectively permeable, which means some materials move through it while others cannot. the movement of materials into and out of the cell is called membrane transport. this activity will you identify the different mechanisms of membrane transport

Imagine that you are a doctor in a maternity ward. during your last shift, 20 babies were born. 10 had blue eyes, and 10 had brown eyes. 15 had round heads, and 5 had pointed heads. what are the parents phenotypes/traits?