Palindrome Sequences

Q.

Identify the wrong statement with regard to Restriction Enzymes.

1. They are useful in genetic engineering.

2. Sticky ends can be joined by using DNA ligases.

3. Each restriction enzyme functions by inspecting the length of a DNA sequence.

4. They cut the strand of DNA at palindromic sites.

Q.

Why are sticky ends better than blunt ends?

Q. Which one of the following represents a palindromic sequence in DNA?

1. 5'- GAATTC-3'
   3'-CTTAAG-5'
2. 5' - CCAATG - 3'
   3' - CAATCC - 5'
3. 5' -CATTAG-3'
   3'-GATAAC-5'
4. 5' - GATACC - 3'
   3' - CCTAAG - 5'

Q.

Which of the following cuts the DNA at specific places?

1. Exonuclease

2. Ligase

3. Restriction endonuclease

4. Alkaline phosphatase

Q.

Identify the incorrect statement regarding restriction endonuclease

1. The enzyme recognizes a specific palindromic nucleotide sequence in the DNA.

2. The enzyme cuts DNA molecules at the identified position within the DNA.

3. The enzyme binds DNA at specific sites and cuts only one of the two strands.

4. The enzyme cuts the sugar-phosphate backbone at specific sites on each strand.

Q. How many fragments will be generated if you digest a linear DNA molecule with a restriction enzyme having four recognition sites on the DNA?

1. 3
2. 6
3. 5
4. 4

Q.
Identify the incorrect statement given below.

1. Each restriction endonuclease recognises a specific palindromic nucleotide sequences in the DNA
2. Restriction enzymes cut the strand of DNA a little away from the centre of the palindrome sites, but between the same two bases on the opposite strand
3. The ends cut by restriction enzymes can be joined together (end-to-end) using DNA ligases
4. Endonucleases remove nucleotides from the ends of the DNA whereas, exonucleases make cuts at specific positions within the DNA

Q. Given below is a short sequence of DNA describing the base pairs on each strand of DNA. What is so special about it?
5’___ GAATTC ___ 3’
3’ ___ CTTAAG ___ 5’

1. Replication completed
2. Deletion mutation
3. Start codon at the 5’ end
4. Palindromic sequence of base pairs

Q. Identify the palindromic sequence among the following.

1. 3' GAATTC 5'
   3' GAATTC 5'
2. 5' GAATTC 3'
   3' CTTAAG 5'
3. 5' GAATTC 3'
   3' GAATTC 5'
4. 5' GAATTC 3'
   5' GAATTC 3'

Q. Which one of the following palindromic base sequences in DNA can be easily cut at about the middle by some particular restriction enzyme?

1. 5' ___ CG TTCG ___ 3'
   3' ___ ATGGTA ___ 5'
2. 5' ___ GATATG ___ 3'
   3' ___ CTACTA ___ 5'
3. 5' ___ GAATTC ___ 3'
   3' ___ CTTAAG ___ 5'
4. 5' ___ CACGTA ___ 3'
   3' ___ CTCAGT ___ 5'