Explanation:
Cells function better at smaller units because if each cell had more areas in the body to take care of, they would need to do more hard work then they already do. Also, if we got scraped, we would lose less small cells then bigger cells. I hope this helped you!
 
        
             
        
        
        
Answer:
The variation might occur in the population that leads to the evolution of the species. This variation may occur due to natural selection, mutation or recombination.
The variation might change the genotype and allelic frequency of the population and might also change the phenotype of the individual in the population. The breeding adults of the left mouthed in 1981, 1987 and 1990 shows variation and was equally opposite phenotype which is more common in the population. 
 
        
             
        
        
        
Answer:
Some examples of predator and prey are lion and zebra, bear and fish, and fox and rabbit. 
Explanation:
 
        
                    
             
        
        
        
Answer:
The spindle fibre is necessary to separate the sister chromatids into opposite sides of the cell. 
Please find detailed explanation below
Explanation:
Mitosis is the cell division that produces two daughter cells that are genetically identical to the parent cell. Mitosis occurs in stages viz: prophase, metaphase, anaphase and telophase. The replicated chromosome, aligns at the centre of the cell in the METAPHASE stage and separates into opposite poles in the ANAPHASE stage. 
This alignment (at the equator) and separation into opposite pole is possible with the aid of a structure called SPINDLE FIBRES. Spindle is a structure formed from microtubules, which attach to the kinetochores (located in the centromere) of each replicated chromosome to separate them from one another. Hence, the purpose of the spindle fibre during mitotic division is to separate the GENETIC MATERIAL of a parent cell into two daughter cells.