DNA sequences for 10 individuals are

...

Question

DNA sequences for 10 individuals are

Nucleotide Position
1 5 10
Person 1 ...GACCTATTGC...
Person 2 ...GAACTATTGC...
Person 3 ...GACCTTTTGC...
Person 4 ...GACCTATTGC...
Person 5 ...CAACTATTGC...
Person 6 ...GACCTTTTGC...
Person 7 ...CAACTATTGC...
Person 8 ...GACCTATTGC...
Person 9 ...CAACTATTGC...
Person 10 ...GAACTATTGC...

Identify the haplotype carried by each person.

Accepted Answer

Hi, everyone. Let's take a look at this practice problem together, consider the following DNA sequence for four individuals. Person, one sequence is A T C G TT A G G AC G T AC person two sequence is A T C G C T A G G AC C T AC person three sequence is A T C G TT A G G AC C T AC and person four sequence is A T C G C T A G G AC G T AC. You want to identify the haplotype sequence for the region between nucleotides five and inclusive which of the following is the most likely haplotype sequence for this region. The answer options are a tt question mark, G G A option B question mark T A G G A option C tt ac question mark T and option DC T AC C question mark. Now, I've rewritten the four individual sequences so that they are larger and easier for us to look at and talk about. I am putting those up on the screen. Now, in addition, I've also marked where nucleotide positions 15, 10 and 15 are. So the question is asking us to look at only nucleotides five through 10 for the four individuals. So I will highlight those nucleotides in each person's sequence. Now, now recall that a haplotype sequence, which is what we are determining is the sequence that contains DNA variants in single nucleotide positions. And recall that we call these variations snips, which is SNP and that is short for single nucleotide polymorphisms. Now, in our answer choices, the question marks represent the snips. So after analyzing and comparing the sequences for only positions five through 10, only position five of our nucleotide sequence varies among the four individuals. And is either A T or AC. That means that the haplotype sequence for this region would be option B question mark T A G G A. So the correct answer is option B again, question mark T A G G A. All right, everyone. I hope you found this helpful and I'll see you soon for the next practice problem.

Key Concepts

Haplotypes

Nucleotide Variations

Genetic Inheritance

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