Answer:
<em>I think the answer might be oxygen</em>
Explanation:
<em>I think this because you need oxygen to survive. Right?!</em>
 
        
             
        
        
        
Answer:
Gastrulation leads to the formation of the three germ layers that give rise during further development to the different organs in the animal body. This process is called organogenesis. Organs develop from the germ layers through the process of differentiation.
 
        
             
        
        
        
Answer:
C
Explanation:
Homologous structures compare the same anatomical features in different species. C is correct because it compares the same trait (wings) in different species (dragonfly vs. bat)
 
        
                    
             
        
        
        
The answer is "autotroph."
        
                    
             
        
        
        
<span>c. numbers of neutrons.</span><span>
Isotopes are atoms of the same element with the same number of protons and same number of electrons but with <span>different number of neutrons. They differ in the number of neutrons that is why they also differ in mass numbers. Since they have the same number of protons, they have the same atomic number. 
For instance, when the nucleus of the isotope with a 68.926 amu, there are 30 protons and 39 neutrons in the nucleus. The best example for this is Zn (zinc-69 isotope) and Ga (gallium-69 isotope) which has 68.926 amu and 68.925 amu respectively. </span></span>