Answer:
B. Cartilaginous fish
Explanation:
Sharks have a cartilaginous skeleton. Cartilage is less dense than bone which allows sharks to move quickly through the water without using too much energy.
 
        
             
        
        
        
Answer;
A) island forms and mainland forms descended from common ancestors.
Explanation;
-Islands tend to host very distinct but limited sets or species; on a given island a spectacular collection of one related group of species would be present and thriving, but many entire families or even higher taxa would be completely absent.
-All the species on the islands and the nearest continent are closely related to one another, however, each species had a set of adaptations that suits it for a particular environment. This means that the island forms and mainland forms descended from common ancestors.
 
        
             
        
        
        
Easy your answer is cumulus
        
                    
             
        
        
        
Answer:
population = 600
heterozygotes = 2pq
The homozygous recessive percentage = 
q = 0.1
 Solve for q:
∴ q = 
 ∴ q = 
 ∴ q = 0.316
solve for p:
for p + q = 1,
thus p = 1 – q = 1 – 0.316 = 0.684  
The heterozygotes = 2pq 
2pq =  2 x 0.316 x 0.684 = 0.432
600 x 0.432 = 259.2  = 259
so,  the population reaches Hardy Weinberg equilibrium, 259 of indviduals should be heterozygous for this trait.
Hence, the correct answer is 259
.