This question comes from the passage called "Recombinant DNA and cloning" within the mcat biological sciences section of khan academy.
the question is:
Which of the following would work as a reverse primer at the SalI site that could be used to amplify yak-1?
Please choose from one of the following options.
The passage contains the following information:
and
The DNA sequence corresponding to the coding region of yak-1 contains 10001000 base pairs, and has the following structure (ATG and TAA correspond to the sites of the start and stop codons, respectively):
5'5′ ATGcttaggcat…(976976 intervening base pairs omitted)…tggcagcccTAA 3'3′
please tell me how to solve this. i literally spent 25+ minutes trying to understand the solution.
Oh - and the hints that Khan gives are:
Primers always go from 5'5′ to 3'3′. Forward primers are complementary from the 3'3′end of the 3'3′ to 5'5′ strand of the template DNA (example of forward primer sequence in yak-1: 5'5′ ATGCTTAGG… 3'3′) and reverse primers are complementary from the 5'5′ end of the 5'5′ to 3'3′ strand of the template DNA (example of backward primer sequence in yak-1: 5'5′ TTAGGGCTG… 3'3′)
Hint #2
To be able to use the restriction enzymes later to cut the plasmid and the amplified DNA, it is necessary to integrate the restriction enzyme site sequence into the reverse primer.
Hint #3
From 3'3′ to 5'5′ strand of the SalI site, we get 5'5′ GTCGACTTA 3'3′. The first nine complementary base pairs from the 3'3′ end of the 5'5′ to 3'3′ template DNA gives us 5'5′ TTAGGGCTG 3'3′ (per Hint 1). So we have 5'5′ GTCGACTTATTAGGGCTG 3'3′.
the question is:
Which of the following would work as a reverse primer at the SalI site that could be used to amplify yak-1?
Please choose from one of the following options.
- 5'5′ CAGCTGTTATTAGGGCTG 3'3′
- 5'5′ GTCGACAATAATCCCGAC 3'3′
- 5'5′ CAGCTGAATAATCCCGAC 3'3′
- 5'5′ GTCGACTTATTAGGGCTG 3'3′
The passage contains the following information:
and
The DNA sequence corresponding to the coding region of yak-1 contains 10001000 base pairs, and has the following structure (ATG and TAA correspond to the sites of the start and stop codons, respectively):
5'5′ ATGcttaggcat…(976976 intervening base pairs omitted)…tggcagcccTAA 3'3′
please tell me how to solve this. i literally spent 25+ minutes trying to understand the solution.
Oh - and the hints that Khan gives are:
Primers always go from 5'5′ to 3'3′. Forward primers are complementary from the 3'3′end of the 3'3′ to 5'5′ strand of the template DNA (example of forward primer sequence in yak-1: 5'5′ ATGCTTAGG… 3'3′) and reverse primers are complementary from the 5'5′ end of the 5'5′ to 3'3′ strand of the template DNA (example of backward primer sequence in yak-1: 5'5′ TTAGGGCTG… 3'3′)
Hint #2
To be able to use the restriction enzymes later to cut the plasmid and the amplified DNA, it is necessary to integrate the restriction enzyme site sequence into the reverse primer.
Hint #3
From 3'3′ to 5'5′ strand of the SalI site, we get 5'5′ GTCGACTTA 3'3′. The first nine complementary base pairs from the 3'3′ end of the 5'5′ to 3'3′ template DNA gives us 5'5′ TTAGGGCTG 3'3′ (per Hint 1). So we have 5'5′ GTCGACTTATTAGGGCTG 3'3′.
