Answer:
the answer is the second one
It could be a common ancestry among organisms.
Answer:
The half-life of a substance is the amount of time it takes for half of that substance to decay. However, after two half-lives, half of the half remaining will decay, leaving you with one quarter of the original substance.
So, after 1 million years you will have 50% of the original substance remaining.
And, after 2 million years you will have 25% of the original substance remaining.
After 3 million years you will have 12.5% of the original substance remaining.
And after 4 million years you will have 6.25% of the original substance remaining.
Explanation:
Hope it helps:)
Our nervous system runs on chemical synapses ! that means we need chemical to transfer information from one neuron to another !
so when the signal reaches the synaptic knob of one neuron , it stimulates the neurotransmitters containing vacuoles to release the neurotransmitters !
the neurotransmitters may be dopamine, acetylcholine etc and after reaching the dendrites of other neuron, it stimulates signal in the other neuron and thus a signal travel from one part of body to other !
