<span>Aplysia is a marine gastropod mollusc which is an often used model organism in neuroscience, especially on the cellular biology of learning and memory. What makes them easy to work with are their giant neurons, which are one of the largest. Aplysia neurons are suitable for studies of how neurons and neural circuits control behaviours. Its defensive reflex has been studied because it is mediated by electrical synapses, which allow several neurons to fire synchronously.</span>
 
        
             
        
        
        
Answer:
student 1
Explanation:
The smooth muscles contract and fatigue slowly but are not striated and are innervated by involuntary nervous system. The cardiac muscles are uninucleate and striated. The skeletal muscles are innervated by the voluntary nervous system hence concerned with voluntary movement.
 
        
             
        
        
        
Proteins are made from Amino acids and, proteins are made by the ribosomes in a cell. <span />
        
                    
             
        
        
        
Darwin lived in a time where natural selection was a strange theory among scientists and researchers. This was especially true when other researcher Lamarck argued that organisms passed on helpful traits to their offspring, that they magically could form a new trait to adapt to their environment and then pass it onto their offspring. For example, if a giraffe was too short to reach food, it would grow a larger neck in its lifetime and then pass that trait onto its offspring. Darwin argued that, through the process of survival of the fittest, that short giraffe would die off and never receive the chance to pass on its shortness to future populations. Thus, taller giraffes would survive— they can reach food, shorter giraffes can’t— and the short genes would disappear. The fact that Darwin was introducing a new theory that nobody was used to at the time was peculiar, so he had few people on his side until long after his observations. 
Another problem Darwin had was the lack of technology. To travel, Darwin would have to use boats to reach far away places, and of course, this took time. 
The final problem Darwin had was the extra time it took for evolution, a process that can take up to millions of years. Evolution didn’t occur over night— it took time for Darwin to conduct experiments, observe, conduct them again, come to a conclusion, and so on. 
Hope this helped a little!