The answer is A, Thalamus. 
 
        
             
        
        
        
Answer:
B. False
Explanation:
No; only a small percentage of variants cause genetic disorders—most have no impact on health or development. For example, some variants alter a gene's DNA sequence but do not change the function of the protein made from the gene.
 
        
                    
             
        
        
        
Answer:
<u><em>Ancestors</em></u>
Explanation:
Ancestors can be described as the persons from which a particular human being originated. In a broader perspective, it is referred to family history of a person. Scientists believe that all organisms on Earth originated from a common ancestor which were the prokaryotes. The prokaryotes with time gave rise to the eukaryotes. Common descent is the phenomenon in which organisms having common ancestors are referred.