The molecular clock has been useful to determine the phylogenetic relationships of species based on the assumption that:

The molecular clock has been useful to determine the phylogenetic relationships of species based on the assumption that they cannot be compared to non molecular methods such as comparative anatomy. The molecular clock helps us discover organisms that have a little common traits or features between evolutionary relationships.

Neurotransmitters are messengers responsible for communication between neurons. they are released from synaptic vesicles and are received by receptors.  the communication is referred to as neurotransmission. the following statement is true about neurotransmitters: a. they're stored in synaptic vesicles in the axon.