Answer:Physical systems differ from social systems because a physical system refers to systems that rely on a group of physical parts to perform a function. Examples of a physical systems are solar systems or even an animals digestive system. Social systems are systems like an ant colony, wolf pack, or a town.
Explanation:
 
        
             
        
        
        
Answer:
The correct answer is B.
Explanation:
Option A is wrong. Mammals were not the prominent species before the extinction of dinosaurs because the mammal species that lived during the dinosaurs' era were so small that they only weighed several grams and occupied small areas as their habitats.
Option C is wrong. As dinosaurs became extinct, reptiles and "birds" remained as their descendant which evolved to some of the species that we know today.
Option D is wrong. Pangea started to break up to form the geographic isolation for the diversion of many species around 175 million years ago.
So the correct answer is B. Massive extinction disrupts and changes the food chain in such a big way that it triggers a domino effect that leads to species adapting to their new environment and diversifying thus forming new species in the process.
I hope this answer helps.
 
        
             
        
        
        
It would decrease as their prime food source would be taken away. This would result in a decline in population as the birds wouldn’t have sufficient food.
Hope that helps. :)
        
             
        
        
        
Answer: possibly A
Explanation: B an C are not it because they are more like mutations. D humans don’t always become immune.
 
        
             
        
        
        
Answer:
12:4:3
Explanation:
Let the lack of color pigmentation which is recessive be aa where AA and Aa allow for color (BB, Bb - black, baby - white).
The F1 parents are BbAa x BbAa
This cross will produce 12/16 blacks, 4/16 albinos and 3/16 white.