Okay, everyone. An mRNA poly a tail has what function? Okay. So remember that the poly a tail is gonna be added to the 3 prime end of the mRNA and a 5 prime cap is added to the 5 prime end of the mRNA during RNA modification, which happens in eukaryotes. But what's the purpose of this? Let's look at answer choice a. Prevents translation. Well, then what's the point of the mRNA if it cannot be translated? So no. This is not the reason for the poly A tail. It does not prevent translation. Answer choice b says it prevents transcription. Well, that would be weird because for the mRNA to even be created, it has to be transcribed. And we know that transcription happens before mRNA modification. So that really doesn't make any sense. It's not going to prevent something that already happened. Answer choice c says that it marks the RNA for degradation. Well, that would suck if you marked it with for degradation, then that protein would never be made. So this is not the correct answer either. In fact, it protects the mRNA from degradation by covering up those linear ends of the mRNA. It is protecting it from being degraded until it is allowed to be translated into a protein. So the correct answer here is answer choice d. An mRNA poly a tail is going to protect the mRNA from being degraded. Okay, everyone. Let's move on to our next video.

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Evolution
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18m

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41m

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17m

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1h 4m

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54m

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21m

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41m

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11m

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4m

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16m

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8m

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2m

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7m

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19m

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49m

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30m

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51m

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14m

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24m

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54m

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13m

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34m

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35m

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6m

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26m

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36m

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52m

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28m

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9m

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48m

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20m

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14m

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10m

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28m

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41m

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22m

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37m

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26m

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55m

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44m

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24m

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57m

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46m

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14m

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26m

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16m

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20m

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3m

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6m

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54m

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7m

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10. The Structure and Function of DNA

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Introduction to Biology

10. The Structure and Function of DNA

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Multiple Choice

A mRNA poly-A tail:

Prevents translation.

Prevents transcription.

Marks the RNA for degradation.

Protects the mRNA from degradation.

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