Answer:
a. establishment of left-right asymmetry
Explanation:
- Cardiac looping is the process in which the heart transforms itself from a straight embryonic heart into a loop that is wounded helically.
- The looping of the heart takes place on the 23rd day of development.
- As a result of this looping, there is bending of the cranial portion of the heart to the towards the right end and the caudal portion of the heart towards the left end.
- At the end of this looping the atrium takes up a dorsal and cranial position and the ventricle is displaced towards left.
- Thus, the outcome of looping is the establishment of left-right asymmetry.
You didn't really provide any possible answers here. However, it's very easy to say that the responsible actors for impulse transmission across the synapses from one nervous cell to another nervous cell is what we call neurotransmitters. These are special molecules that can have different effects when binding onto the required receptor sites.
<u>Answer</u>: (1 is the oldest event)
1. Europe sent explorer and merchants along the Silk Road and across the Indian Ocean
2. European nations colonized countries in Southeast Asia
3. World War II broke out in Europe as well as in East Asia and Southeast Asia
4. Nations in Southeast Asia demanded and won independence
Multiple nations in Southeast Asia obtained their independence after World War II some as late as 1975 (Portuguese Timor - now East Timor).