Nerve cells release neurotransmitters across gaps and secretion of proteins and wastes: it’s Exocytosis
        
             
        
        
        
Punnet squares are a useful tool for predicting what the offspring will look like when mating plants or animals. Reginald Crundall Punnett, a mathematician, came up with these in 1905, long after Mendel's experiments. Let's take a look at how Punnet squares work using the yellow and green peas example from im not sure about the tree by three thing but maybe this will help :)
 
        
             
        
        
        
Answer: Most autotrophs use a process called photosynthesis to make their food. In photosynthesis, autotrophs use energy from the sun to convert water from the soil and carbon dioxide from the air into a nutrient called glucose.
Explanation:
 
        
                    
             
        
        
        
Answer:
c. mosses
Explanation:
Primary succession occurs in places that have never been occupied by a community. Simple species are established first, as they help enrich the soil, allowing other species to become established. The first organisms to appear in areas of primary succession are often pioneer species such as mosses or lichens. 
Hope this helps. :)
 
        
             
        
        
        
The oxygen cycle can be found in all but the geosphere. There's oxygen in the atmosphere, so it has to be there, and the biosphere includes living things, which breathe oxygen, and water (hydrosphere) is made up of partly hydrogen, so there has to be oxygen there as well.