Answer:
they have to remain small because nutrients go around faster around the cell then bigger cells
Explanation:
hopefully i explained it well
 
        
             
        
        
        
Answer:
The correct answer will be option-B
Explanation:
A species is a group of similar organisms which interbreed with the individual of the same group of closely related individuals.
Species are reproductively isolated by various mechanisms, one of which is due to the behavior.
When the species are not able to reproduce to different species due to the differences in their behaviour in terms of mating rituals which could be due to different mating rituals or a different way of mating like observed in the grasshoppers is known as behavioral reproductive isolating mechanism.
In grasshoppers, the grasshopper's species cannot interbreed due to the differences in the mating songs as a part of the behavior.
Thus, Option-B is the correct answer.
 
        
             
        
        
        
The centre of the nucleus is an atom
 
        
             
        
        
        
Answer:
respiratory and excretory systems are among the two vital systems in our body which work in order to maintain our health or keep our body fit
Explanation:
Respiratory systems comprises of organs like lungs to inhale oxygen and exhale carbon dioxide out of our body. The oxygen is then mixed with blood by the heart and reaches different parts of our body.
Excretory system is responsible for excreting or expelling the waste out of our body to keep our body free from toxins and harmful chemicals. 
excretory system works with respiratory system to get rid of water vapors and carbon dioxide in the human body. 
 
        
             
        
        
        
I think the population of deer will increase