The following is a code for a strand of DNA.

a. Using the genetic code provided in Figure 8.8, fill in the blanks to complete the segment of DNA shown.
b. Fill in the blanks to complete the sequence of amino acids coded for by this strand of DNA.
c. Write the code for the complementary strand of DNA completed in part (a).
d. What would be the effect if C were substituted for T at base 10?
e. What would be the effect if A were substituted for G at base 11?
f. What would be the effect if G were substituted for T at base 14?
g. What would be the effect if C were inserted between bases 9 and 10?
h. How would UV radiation affect this strand of DNA?
i. Identify a nonsense sequence in this strand of DNA.

Question

The following is a code for a strand of DNA.

a. Using the genetic code provided in Figure 8.8, fill in the blanks to complete the segment of DNA shown.

b. Fill in the blanks to complete the sequence of amino acids coded for by this strand of DNA.

c. Write the code for the complementary strand of DNA completed in part (a).

d. What would be the effect if C were substituted for T at base 10?

e. What would be the effect if A were substituted for G at base 11?

f. What would be the effect if G were substituted for T at base 14?

g. What would be the effect if C were inserted between bases 9 and 10?

h. How would UV radiation affect this strand of DNA?

i. Identify a nonsense sequence in this strand of DNA.

Accepted Answer

Hi, everyone. Let's take a look at the next problem. Identify the correct sequence of the coding strand of DNA for the following MRN A sequence, five prime A, Auuuagg, a AC Cucag three prime. And we have four different multiple choice options. Each of which are different DNA sequences. And importantly, each one is labeled five prime and three prime, but they're not all in the same orientation, some are written five prime to three prime, some three prime to five prime. Now, I'm not going to read every single sequence out here all in a row. We'll instead look at them one at a time as we figure out what our sequence should be. So the main trick when doing this is we have to keep straight, which strands are complementary to each other versus which ones will be the same bases in the same order. So we know we start with our DNA and we have our coding strand and our non coding strand which are of course complementary to each other. And which one is the template for MRN A. So which one is complemented with MRN A? Well, that's the non coding strand. So the MRN A is transcribed using a non coding strand as a template. Sometimes that gets a little hard to keep straight. But if we just remember the reason it's called the coding strand is that we can look at when we want to look at the coons that designate our amino acids. Looking at the coding strand tells us it's more easy to compare the order of those bases and look at the coons. So our MRN A will have essentially the same sequence of bases, the same orientation as the coding strand, except for obviously, the DNA will have limine where the MRN A has UOL. So let's look at our RN A strand, I'm going to copy, paste it to give myself a little more space. So it's written five prime to three prime. We are not making a complementary strand. So we're going to write our DNA coding strand in the same order. So we start with five prime. Now, does this mean we can eliminate answer choices that start with three prime? No, it doesn't because perhaps the strategy is written in the opposite direction, we need to check if the bases match up whether we need to read it left or right or right to left. We just look for that five prime to start us off. So again, we're using the same basis with the exception of U cell and thymine. So we have a A and our MRN A strand. So our DNA strand will also be a, a, then our MRN A has UUU, so we'll have T TT and then the next three bases are a GG. So our DNA will also have a GG. Now, I'm not even going to go through the whole strand. I'm on a test. I might be in a hurry. There's a good chance I'll be able to get down to one answer choice just with this batch here. This is a multiple choice question. But for free response, obviously, I'd need to do the whole strand. But let's take a look at my answer choices. So I'm starting with a five prime slide choice. A also starts with five prime and the bases are a att Tagg. So it matches up to that point. So I'm just underlining it and we'll leave it there. It's a possibility. Choice B starts with three prime sign on the left. So I need to read it right to left to see if it's the same. So let's look at the right side which is five prime, but then I have G AC T. So no, this is not correct. Clearly. This is looking at perhaps the complimentary order there and it's starting with three prime rather than five prime. So it's trying to mix you up as to which orientation you would look at this strand. Choice C starts on the five prime end and then has TT AAA TCC. So this is writing complementary base which makes it incorrect since we want the same basis except for that T and U. So C is incorrect. And then finally, choice D is written three prime to five prime. If we look at the right side, the five prime end it has ctgagg so not correct. So indeed, just with going that far choice say is our only answer possibility left. So the correct sequence of the coding strand of DNA from RMRN A sequence is choice a five prime A att Tagg A AC CTCAG. See you in the next video.

Verified Solution

Key Concepts

DNA Structure and Function

Mutations and Their Effects

Transcription and Translation