Answer:
1677
Explanation:
Robert Plot discovered the first dinosaur bone, they thought It was just a human bone but later they found out it was a dinosaur bone.
 
        
             
        
        
        
Deforestation encourages flooding by allowing water to run off into streams
<u>Explanation</u>:
Deforestation plays vital roles in the flooding. The roots of the Trees prevent sediment runoffs and forests hold more water than farms or grasslands.Firstly the leaves in the trees will capture some amounts of water which will be eventually evaporated. Secondly, some quantity of water is  absorbed by the tree's roots. Also,Tree roots hold the soil in place, reducing the movement of sediment that can shrink river channels downstream.. 
The process of deforestation will lead to dislodging of the topsoil. this makes the  topsoil unstable and reduces its capacity to hold down the water
 
        
             
        
        
        
I will answer the question accordingly so that it help you under stand it better.
Question A. 
During an extreme heat wave, plants with white flowers survive better.
What mechanism is in work here?
Answer: Mechanism of Natural Selection
 will work here. This is called survival of the fittest which means the best color which fits in harsh conditions will dominate over others and will survive for longer time.
What is the effect on the gene pool?
Answer: The Frequency of white allele will increases
 because white color is the best fit to extreme heat wave.
Question B.
A person uproots the five closest plants, which all happen to have white flowers.
What mechanism is in work here?
Answer: The mechanism of gene flow will work here as color of flower represents genotype of flower.
What is the effect on the gene pool?
Answer: The Frequency of white allele will increases because genotype of white flowers is increased.
 
        
             
        
        
        
Answer:
The two main tissues responsible for structural support are compact bone and ligaments.