Grazing animals such as deer are primary consumers.
        
                    
             
        
        
        
B. Thick Atmosphere 
Let me know how it goes!
        
                    
             
        
        
        
This is all i know about caves: Caves are large, natural holes beneath the surface of the earth. Underground passages and caves are found in rocky landscapes across the world. They are found in areas with a lot of limestone, a common type of rock. They can be created in various ways, but most caves are hollowed out of rock by water.
 
        
                    
             
        
        
        
Answer:
See explanation
Explanation:
Darwin proposed his theory of evolution on the premise of natural selection. According to him, organisms which possess favourable characteristics which enable them to survive in their environment are more likely to survive and reproduce, passing on these favourable characteristics to their offsprings.
According to Mendel, the unit of inheritance passed on from parents to offspring are genes. Hence Darwin's factors are Mendel's genes.
If Darwin knew of Mendel's work. It might have influenced his presentation of the idea of passing on favourable characteristics from parents to offspring in the light of genetics.
This would have made Darwin's work to have more empirical backing hence making it more widely accepted.