Answer: Genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).
By the end of meiosis, the resulting reproductive cells, or gametes, each have 23 genetically unique chromosomes. The overall process of meiosis produces four daughter cells from one single parent cell.
Explanation:
During meiosis, homologous chromosomes (1 from each parent) pair along their lengths. The chromosomes cross over at points called chiasma. At each chiasma, the chromosomes break and rejoin, trading some of their genes. This recombination results in genetic variation.
 
        
             
        
        
        
1. C) Change in fossil fuel use
2. C) Reduce the amount of fossil fuels used
 
        
             
        
        
        
The most important nursing intervention is to look for the client’s
oral hygiene frequent and after meals. After a period of two or three weeks
further irritation of the gland develops from the radioactivity and the patient
may notice burning on urination, pressure, 
frequency and some slight rectal irritation or diarrhea. 
 
        
             
        
        
        
This is the anaphase of mitosis. Anaphase is characterized by the separation of sister chromatids or "pulling away" of the sister chromatids from the metaphase plate to the opposite spindle poles. This is also the phase where chromosomes reach its maximum condensation meaning that the process of the reformation of the nucleus will be shorter and easier.
        
             
        
        
        
Answer:
Well I think your able to identify by looking at the Physical and Chemical Properties or by its Melting or boiling point. 
Hopefully this is correct