GENETICS AND EVOLUTION
MOLECULAR BASIS OF INHERITANCE
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
enzymes that destroyed proteins also destroyed transforming activity
|
|
|
enzymes that destroyed nucleic acids also destroyed transforming activity
|
|
|
enzymes that destroyed complex carbohydrates also destroyed transforming activity
|
|
|
the transformation activity was destroyed by boiling
|
Detailed explanation-1: -Avery, MacLeod and McCarty identified DNA as the “transforming principle” while studying Streptococcus pneumoniae, bacteria that can cause pneumonia.
Detailed explanation-2: -Avery and McCarty observed that proteases-enzymes that degrade proteins-did not destroy the transforming principle. Neither did lipases-enzymes that digest lipids. They found that the transforming substance was rich in nucleic acids, but Ribonuclease, which digests RNA, did not inactivate the substance.
Detailed explanation-3: -What is the explanation of why Avery, MacLeod, and McCarty’s in vitro transformation experiment showed that DNA, but not RNA or protein, is the hereditary molecule? The experiment showed that enzymes that destroyed RNA and protein did not destroy the transforming principle, whereas enzymes that destroyed DNA did.
Detailed explanation-4: -In a very simple experiment, Oswald Avery’s group showed that DNA was the “transforming principle.” When isolated from one strain of bacteria, DNA was able to transform another strain and confer characteristics onto that second strain. DNA was carrying hereditary information.