GENETICS AND EVOLUTION
MOLECULAR BASIS OF INHERITANCE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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nucleoside triphosphates because of the ability to add and remove phosphate groups
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proteins because they were thought to be the only molecule with both the variety and specificity of function to account for the array of heritable traits observed
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amino acids because of all the ways they can join together
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carbohydrates because they are found in abundance in all organisms
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Detailed explanation-1: -Alfred Hershey and Martha Chase showed that only the DNA of a virus needs to enter a bacterium to infect it. Their experiment provided strong support for the idea that genes are made of DNA. They firmly restated the conclusion that Avery, et al. had more tentatively proposed in 1944.
Detailed explanation-2: -So, the correct option is ‘Phosphate was used to tag DNA because DNA contains phosphorus within its structure (specifically the backbone), while proteins do not, and would make the bacterial cell radioactive as DNA entered and took over control.
Detailed explanation-3: -Hershey and Chase established whether the phage injected DNA or protein into host bacteria. They prepared two samples of phage: ³⁵S, which labels protein and ³²P, which labels DNA. It was found that only ³²P entered the bacterial cells, indicating that DNA, not protein, is the genetic material.