(85 points! ) a nerve signal is like a wave. how does this work?

a: an electrical wave moves down the axon by electrons moving from the place the signal started to the place it ends up.
b: a wave of reversal of the negative electrical potential inside the cell passes along the axon with ions moving in and out of the axon.
c: a wave of movement passes down the axon, in which the whole axon moves sideways in one place and then the next.
d: the density of the cytoplasm inside the axon changes from one place to the next as the signal moves along the axon.

The sketch shows a rynchosaur, an extinct animal that is known only from fossils. there has been much debate about the classification of these creatures. some scientists suggest that they belong with primitive amphibians, and some think they are related to snakes and lizards.the data equally support both cases. which statement best explains how to draw a cladogram that includes the rynchosaur? draw the cladogram for amphibians. draw the cladogram for reptiles. draw two cladograms, both showing the traits, and leave it as a hypothesis. draw two cladograms, both showing the traits, and have scientists vote

Look at the photo of the leaf. which term best describes this leaf?

What molecules will be best used to compare different species with the exact same sequence of amino acids? why would two species have the same protein even if the molecules in question is different? (hint: transcription to translation to protein).