Less expensive source of energy is available.
hope this helped, please mark brainliest :)
 
        
                    
             
        
        
        
Answer: 
I) Sexual reproduction 
II) Mutation 
Explanation:
Variations refer to the difference observed within organisms of the same species. Variation are introduced into a population by:
- new genetic combinations that occur during sexual reproduction (i.e during meiosis)
- mutations, spontaneous changes that occur in genes and chromosomes.
 
        
             
        
        
        
Answer:
atomic orbitals or subshells it the same name
 
        
             
        
        
        
The shirt is soft
and red: Qualitative 
It is 72 degrees 
Fahrenheit outside: Qualitative 
The river flows more
quickly in the spring
than in the summer: Quantitative 
There are eight elephants
over the age of six: Qualitative