Exploring DNA Structure and Replication

The video tutorial explains DNA as the carrier of genetic information, detailing its structure as a polymer of nucleotides with a sugar-phosphate backbone and nitrogenous bases. It covers DNA replication, highlighting the semiconservative model proven by the Meselson-Stahl experiment. The process involves enzymes like helicase and DNA polymerase, with differences in replication between leading and lagging strands. The tutorial concludes with the final steps of replication, ensuring two identical DNA copies.

What is the primary function of DNA?

• To transport oxygen

• To digest food

• To store genetic information

• To provide energy for cells

Which nitrogenous base pairs with adenine in DNA?

• Thymine

• Guanine

• Cytosine

• Uracil

What is the nature of DNA replication?

• Dispersive

• Semiconservative

• Random

• Conservative

Which experiment proved the semiconservative nature of DNA replication?

• Griffith's experiment

• Hershey-Chase experiment

• Meselson-Stahl experiment

• Avery-MacLeod-McCarty experiment

What is the role of helicase in DNA replication?

• To join Okazaki fragments

• To relieve strain on the double helix

• To synthesize RNA primers

• To unwind the double helix

Which enzyme synthesizes short RNA sequences called primers?

• Ligase

• DNA polymerase

• Helicase

• DNA primase

In which direction does DNA polymerase synthesize new DNA?

• 3' to 5'

• Both directions

• 5' to 3'

• Random

What are the short DNA fragments synthesized on the lagging strand called?

• Exons

• Primers

• Okazaki fragments

• Nucleotides

Which enzyme removes RNA primers during DNA replication?

• Exonuclease

• Ligase

• DNA polymerase I

• Helicase

What is the final step in DNA replication?

• Relieving strain on the double helix

• Synthesizing RNA primers

• Sealing the gaps between Okazaki fragments

• Unwinding the double helix