Answer:
Let's complete the question by writing the sequence, from earliest to most recent options
a. 2 → 1 → 3 → 4
b. 2 → 4 → 3 → 1
c. 2 → 3 → 1 → 4
d. 2 → 1 → 4 → 3
e. 2 → 4 → 1 → 3
It's surely going to be e.
e. 2 → 4 → 1 → 3
2. Cambrian explosion occurs.
4. Vertebrates become top predators in the seas.
1. Protostomes invade terrestrial environments.
3. Deuterostomes invade terrestrial environments.
Got it!
I think in real life because you get to see how they act and i have been on three trips i know that this is not related but I've been to Egypt and Italy and china and i am in 7th grade so ya. I think seeing animals and things in real life is the best thing to do overall.
Answer:
low level of calcium would result in fewer signals sent between pre and post synaptic cells.
Explanation:
The calcium has a main role in signal transmission mechanism and here is the mechanism :
1-the impulse reaches the synapse (depolarization which is a voltage change).
2-the voltage gated calcium channels open and let calcium flow into the cell.
3-the calcium causes the synaptic vesicles to rupture and release chemical transmitters which cross the synaptic cleft and finally bind to receptors on the post synaptic cell (transmitting the signal)
so it's obvious that if calcium concentration decreases, the signal transmission also decreases.