You perform Sanger sequencing on a small fragment of the human genome and obtain the following small sequence read: 5' AGGCTTAAGCTTAATCGGGCTAT 3'. In order to determine if this sequence might be within the coding region of a gene, you examine it for open reading frames. How many open reading frames exist that go all the way through this DNA fragment?

Explanation:

Dna sequence : 5' AGGCTTAAGCTTAATCGGGCTAT3'

mRna is complementary to the DNA strand ( template strand)

mRNA synthesis occur in 5'-3' direction.

mRNA sequence :

5' UCCGAAUUCGAAUUAGCCCGAUA3'

READING FRAMES :

5' UC CGA AUU CGA AUU AGC CCG AUA 3'

5' U CCG AAU UCG AAU UAG CCC GAU A 3' ( contain one stop codon).

5' UCC GAA UUC GAA UUA GCC CGA UA 3'

Total there are 2 reading frame.

Open reading frame are those which does not contain stop codon that is why they are called open.