I do believe that it is C. crossing over :) I hope that is correct, it seems like the only plausible answer. 
        
             
        
        
        
Answer:
The correct answer is: d. Carassius is a group of different organisms with similar structures, while auratus is a smaller group of members that can only breed with another auratus.
Explanation:
Carassius signifies the name of genus. In binomial terminology it is the generic name shared by the collection of nearby families. In this case, Carassius is a genus in the family of ray-finned fishes. Auratus signifies the types of the fish and it is detailed exclusive epithet within the type. Carassius is a type in the ray-finned fish family Cyprinidae. Maximum types in this genus are usually identified as crucian carps, however this tenure often precisely denotes to C. carassius. The most well known is the goldfish (C. auratus).
 
        
             
        
        
        
Answer:
Relative Dating with Fossils: Index Fossils as Indicators of Time
Explanation:
 
        
                    
             
        
        
        
Answer:
B. neuroglia.
Explanation:
Neuroglia, also called glial cells are cells that support neurons structurally and functionally.
There exists two broad classes of cells in the nervous system which are:
- Neurons
- Glia
The neurons process information while the glia support the neuron mechanically and metabolically.
In general, there are three main types of cells that make up the nervous system including the above two.
 
        
             
        
        
        
The Answer is true my friend
You're welcome