Your answer is 
One of the most effective methods that can be used by researchers to avoid sampling bias is simple random sampling, in which samples are chosen strictly by chance. This provides equal odds for every member of the population to be chosen as a participant in the study at hand.
 
        
                    
             
        
        
        
I believe the correct answer would be metabolism. This comprises all of the reactions inside organisms that allows them to sustain life. There are two categories of such namely, anabolism and catabolism. Hope this answers the question.
        
                    
             
        
        
        
 Explanation:
The Germ Theory of Disease  indicates that microbes are the causal agents in human disease.  In modern healthcare, Germ Theory has led to a breakthrough in the treatment of infectious diseases with antibiotics such as penicillin, and the prevention of disease outbreaks through proper sanitation and vaccination. 
Further  Explanation:
Biology's unifying principle states that cells are the basic units of biological organisms. Cells sharing a similar origin, group together in the body to form tissues; these typically share physical features and are arranged in regular patterns. All living things, grow, respire, reproduce etc. these processes are carried out by cells, which are thus integral to their survival.
Before the discovery of cells by Robert Hooke in 1665 with a simple microscope, many scientists had long believed that life rose spontaneously over extended periods of time. Circa 1668 Francesco Redi, challenged the idea of spontaneous generation of maggots from rotting meat by placing meat in various sealed open, partially sealed and sealed containers. Sealed containers did not show the presence of maggots, and he theorized that these were likely from eggs laid on the meat by flies. This was the development of the theory disproving abiogenesis (cells arise from other living cells); this eventually proved the unifying principle we know today.
Cell theory states that living things are comprised of cells, as their smallest units capable of functioning. Microscopy helps to prove this, as cells and their varying components can readily be seen, observed and later classified. 
Learn more about cellular life at brainly.com/question/11259903
Learn more about tissue types at brainly.com/question/8487952
#LearnWithBrainly
 
        
             
        
        
        
You mixing stuff pppppppoopopppppppppp
        
             
        
        
        
Answer:
The kinetochore of the chromosomes
Explanation:
<em>What could be damaged that is hindering the spindle fibers from attaching to the chromosomes are the kinetochores of the chromosomes.</em>
At the metaphase stage of the cell division, the chromosomes align at the equator of the cell and the spindle fibers engage each chromosome at a region known as the kinetochore. 
The kinetochore is made up of complex proteins and lies around the centromere region of the chromosome. The microtubules of the spindle fibers attach to this region during the metaphase stage.
<u>If the kinetochore is damaged, it means the spindle fiber will not be able to attach to the chromosome. </u>