Limitations
Light microscopes can magnify specimens or objects up to fifteen hundred times their actual size. This is amazing if you consider objects naturally visible to the eyes. But when you consider microscopic specimens then the magnification is not very impressive. Also the depth of field is confined. For very specific observations of elements or specimens that are smaller than 0.275 microns or smaller than half the wavelength of white light require electron microscope.
 
        
                    
             
        
        
        
Mitosis is important for a number of reasons. It's a form of reproduction for some organisms that reproduce asexually, it's needed for growth and development, and also for the repair and replacement of cells. If we didn't do mitosis dead cells wouldn't be replaced, and that would cause some massive problems. For example, if we weren't capable of doing mitosis and you cut your hand, the cut wouldn't heal up because the cells wouldn't be getting replaced. 
        
                    
             
        
        
        
Answer:
Gastrula
Explanation:
A hollow shaped embryonic structure formed after two weeks of fertilization with three layers is known as gastrula.
The gastrula is formed from the repeated division of the single-layered structured called blastula which later forms three layers called ectoderm, endoderm and mesoderm.
These layers during the process of gastrulation from different organs of the multicellular organisms like the endoderm forms the liver, the ectoderm form the nervous system, the skeletal bone and many others.
Since gastrula structure contains three dermal layers therefore gastrula is the correct answer.
 
        
             
        
        
        
Frontal Wedging... 
Cold and Warm fronts
Dew Point...
The % of water vapor in the air
 
        
             
        
        
        
A Personal Experience Timeline helps the writer generate a topic. The writer can use the timeline to see specific moments in their lifetime. The correct answer will be A.