DNA Structures and Replication

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What is the approximate size range of plasmids in terms of base pairs (bp)?

10^3 - 10^5 bp (correct)

10^5 - 10^7 bp

10^2 - 10^4 bp

10^4 - 10^6 bp

Which type of enzyme cleaves DNA strands at specific DNA sequences?

Ligase

Endonuclease (correct)

Helicase

Polymerase

Which enzyme is responsible for hydrolyzing the phosphodiester bond within a polynucleotide chain?

Restriction enzyme

Polymerase

Endonuclease (correct)

Exonuclease

What is the approximate length of the E.coli chromosome DNA?

1.7 mm Signup and view all the answers

Why is DNA supercoiling important in bacterial cells?

To compact DNA within the small cell size Signup and view all the answers

What property makes poly-deoxyribonucleotides suitable for long-term storage of genetic information?

High stability of phosphodiester bonds Signup and view all the answers

What was the turning point in DNA development that gave rise to modern molecular biology?

Discovery of the double helix structure by Watson and Crick Signup and view all the answers

In the structure of DNA, where are the phosphate and sugar groups located?

On the outside of the helix Signup and view all the answers

What type of DNA structure twists in a clockwise direction?

Double helix Signup and view all the answers

Which model of DNA structure was proposed by Watson and Crick?

Double helix Signup and view all the answers

What is the main function of DNA polymerases?

Catalyzing DNA replication Signup and view all the answers

What is the purpose of telomere maintenance in DNA?

Preventing degradation of chromosomes during replication Signup and view all the answers

What are the three families of LINE elements?

LINE1, LINE2, LINE3 Signup and view all the answers

Which retroelement is known for lacking autonomous transposition capability?

SINE Signup and view all the answers

What is the most common SINE element?

Alu Signup and view all the answers

Why can the insertion of LINE1, Alu, and SINE sequences into coding regions of genes lead to genetic diseases?

They cause gene inactivation Signup and view all the answers

Under what conditions has transposition of SINE and LINE elements been observed?

In vitro Signup and view all the answers

What is the status of LINE1 sequences with respect to active transposition in the human genome?

Majority are dormant or deactivated Signup and view all the answers

What types of base-to-base interactions determine the stability of the DNA double helix?

Base stacking (π stacking) and hydrophobic interactions Signup and view all the answers

What initiated a new era of biology according to Watson and Crick's 1953 paper in Nature?

The suggestion of the structure of the DNA double helix Signup and view all the answers

Where do deep major grooves occur in the DNA double helix?

Where sugar-phosphate skeletons are far apart Signup and view all the answers

What did Watson and Crick want to suggest in their 1953 paper?

The structure of the nucleic acid salt of deoxyribose (DNA) Signup and view all the answers

What kind of pairing do complementary nucleotide strands exhibit in the DNA double helix?

Antiparallel pairing Signup and view all the answers

Where do proteins that bind DNA interact specifically according to the text?

With major and minor grooves Signup and view all the answers

What is the main function of DNA helicase in the replication process?

Separating DNA strands Signup and view all the answers

Which enzyme is responsible for synthesizing a short RNA primer during replication?

RNA polymerase Signup and view all the answers

What is the function of single-strand binding proteins (SSB) during replication?

Bind to single-stranded fragments to prevent hairpin-like structures Signup and view all the answers

Why is DNA Polymerase unable to initiate the synthesis of a new DNA strand from scratch?

Requirement for a short RNA primer Signup and view all the answers

What are the small DNA fragments on the lagging strand called?

Okazaki fragments Signup and view all the answers

Which enzyme initiates replication in eukaryotes by synthesizing a short primer?