Hi,
Harshey and Chase did a great experimentation which was basically a two step experiment to prove that DNA and not proteins are the actual carriers of genetic information from parents to offspring.
- In the first part of their experiment, they used bacteriophages (virus that eat bacteria). They used radioactively labeled sulphur(35S) medium to grow bacteriophages and observed that all the bacteriophages had proteins with radioactive sulphur(35S).
- In the next step they allowed these phages to infect bacteria and to their surprise, they found that the bacteria did not had radioactively labeled sulphur in them because the coat of bacteriophage stays outside the body of bacteria when it attacks it. This proved that DNA not proteins were the hereditary material.
- To make their results more reliable, they did a second experimentation in which, they marked the DNA of the phage with radioactive phosphorus 32P. After labeling DNA, they repeated the same experiment and this time, they found radioactive phosphorus inside the bacteria. 
<em>This meant that the bacteria had DNA of phage entered inside them and this again proved that DNA not proteins are the hereditary material. You can see attached image for better understanding.
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Hope it help!
 
        
             
        
        
        
Answer:
D. hotter rock rises and cooler rock sinks.
Explanation:
We know that as we move <u>towards Earth's center</u>, the <u>temperature rises</u>. This rise in temperature causes rocks to melt (magma). The high temperature and melting of rocks <u>decrease the density of material </u>which makes it <u>move upward</u>. By <u>moving upward</u>, the molten rock <u>starts turning solid</u> and becomes <u>denser again</u>. Here, it <u>sinks back due to gravity</u>. This upward and downward movement of rocks due to density and temperature makes a convection cell. 
PS: The formation of convection cells in Earth's interior is also the reason for plate tectonics.
 
        
                    
             
        
        
        
Additional detail found elsewhere: (T = Tall and t = short) 
Answer:
All are expected to be tall
Explanation:
We are told that the T allele produces the tall trait, and the t allele produces the short trait. 
Because the tall allele is denoted by an uppercase letter, it means it is the dominant allele, meaning if it is present even in one copy, the trait will be expressed. This is in contrast to the recessive short allele, 2 copies are needed for the trait to be expressed.
Individuals have 2 copies of every gene. Offspring that are TT, Tt, TT, and Tt all have at least one copy of the T (tall allele). Because this is the dominant allele, that means all of these offspring would be expected to be tall. 
 
        
             
        
        
        
Answer:
Enzyme A
Explanation:
<em>Hello there?</em>
In the stomach, hydrochloric acid is present which is a strong acid (0-4) which is below pH 7. Therefore an enzyme that act best well here should be below pH 7 which for our case is A. 
<em>I</em><em> </em><em>hope</em><em> </em><em>this </em><em>helps </em><em>have </em><em>a </em><em>nice </em><em>studies.</em><em />