Answer:
A) species diversity tends to increase as a result of ecological succession.
Explanation:
 
        
             
        
        
        
Answer:
Density is nearly 3 cabs per hectare
Explanation:
Given - 
There are three three intertidal regions. 
Area of each intertidal region is 
 hectares.
Number of crab in the intertidal regions are as follows - 
Intertidal region I - 7
Intertidal region I - 2
Intertidal region I - 6
Sum of crabs in all three regions is equal to 

Total area of all three intertidal regions is equal to 
 hectares
Now density per hectare is equal to total population of crab divided by total area of all the three intertidal regions 
Density 
Density is nearly 3 cabs per hectare
 
        
             
        
        
        
Answer:
Amino acids with non-polar side chains. 
Explanation:
The class of proteins that is unable to form hydrogen bonds with water are the amino acids with non- polar side chains. This class includes the amino acids 
Alanine
Valine
Leucine
Isoleucine
 Proline 
Phenylalanine
Cysteine 
 Methionine
 Tryptophan 
These are the nine proteins which are considered to be strongly hydrophobic. All these amino acids are hydrophobic in nature due to their side chains. Glycine is not added to this list as it does not have a side chain. 
 
        
             
        
        
        
Develop from a single fertilized egg and have identical genes.
        
             
        
        
        
Answer:
The skeletal system provides a frame to
support and protect the body and allows the
body to move.