Answer: Medication can be tested on the cancer culture before being injected into the patient.
 
        
             
        
        
        
Bears eat plants such as berries, and plants get their energy from the sun. So his energy source's energy source is sunlight, which also makes it his energy source
        
             
        
        
        
the actual CORRECT answer is change.
So,
The environment needs to [change] in order for natural selection to occur.
Don't worry i took the test trust me!
 
        
                    
             
        
        
        
excretory system: removes waste from blood.
respiratory system: obtains oxygen so the energy in the nutrients can be extracted.
circulatory system: transports nutrients from small intestine to the othet tissues.
nervous system: regulates and controls digestive functioning.
( Am not completly sure, but i think this is the answer)
 
        
             
        
        
        
Answer:
None of the choices would lead to all identical gametes. 
Explanation:
Gametes are sex cells produced by sexually reproducing organims via a process of cell division called MEIOSIS. Meiosis is a cell division process which produces four (4) daughter cells (gametes), which are genetically different from the parent cell. 
The difference in genetical content is as a result of a process unique to only meiosis called CROSSING-OVER OR RECOMBINATION. This process ensures that the genetic content of the gametes are altered. Hence, since gamete formation is done via meiosis, none of the scenarios in the option will lead to all identical gametes.