Answer:
The correct answer is option b. "20 H1, 40 H2A".
Explanation:
Chromatin is a complex that protects and condenses the genetic material comprised of DNA and proteins. When chromatin is in the form of a 30 nm fibril, nucleosomes have a regular positioning along the DNA. This means that each nucleosome is associated with a single H1 molecule. Therefore a chromatin containing 20 nucleosomes will have 20 copies of H1 and 40 copies of H2A, because each nucleosome has 2 copies of the core histone H2A.
 
        
             
        
        
        
PLASMA IS POSITIVELY AND NEGATIVELY CHARGED NOT GAS
 
        
                    
             
        
        
        
Answer:
An embryo is the early stage of human growth in which the vital body structures of organs are developed. In the 11th week of pregnancy, which is the 9th week of development after egg fertilization, an embryo is considered a fetus.
Explanation:
 
        
                    
             
        
        
        
Answer:
C) Practicing good scientific method and practices.
Explanation:
 The text states, "repeating the experiment multiple times," as well as other preparations that a good scientist uses. 
 Doing something multiple times over is a good sign of a good scientific method.
  Taking careful measurements, having several researchers run the same experiment, and only testing one variable at a time are all good practices that a scientist should use.
 <em> </em><em><u>The</u></em><em><u> </u></em><em><u>correct</u></em><em><u> </u></em><em><u>answer</u></em><em><u> </u></em><em><u>is</u></em><em><u> </u></em><em><u>C</u></em><em><u>)</u></em><em><u>.</u></em>