Structure of DNA

The video tutorial explores the discovery and structure of nucleic acids, focusing on DNA and RNA. It begins with the historical identification of nuclein and the introduction of nucleic acids by Richard Altman. The tutorial explains the components of nucleotides, including nitrogenous bases, sugars, and phosphoric acid, and distinguishes between DNA and RNA. It covers the types of bases, purines and pyrimidines, and their pairing rules. The video also discusses the formation of polynucleotides, Chargaff's rules, and the DNA double helix model proposed by Watson and Crick. Finally, it describes the different forms of DNA, such as B, A, and Z DNA, and their structural characteristics.

Who introduced the term 'nucleic acid'?

• Maurice Wilkins

• Richard Altman

• Rosalind Franklin

• Erwin Chargaff

What is the main difference between the sugars in DNA and RNA?

• DNA has ribose sugar, RNA has deoxyribose sugar

• DNA has deoxyribose sugar, RNA has ribose sugar

• Both have ribose sugar

• Both have deoxyribose sugar

Which of the following is a purine base?

• Adenine

• Uracil

• Cytosine

• Thymine

What type of bond connects adjacent nucleotides in a polynucleotide chain?

• Phosphodiester bond

• Covalent bond

• Ionic bond

• Hydrogen bond

According to Chargaff's rules, which of the following is true?

• Adenine equals thymine

• Adenine equals guanine

• Thymine equals guanine

• Cytosine equals adenine

What is the handedness of the B form of DNA?

• Right-handed

• Left-handed

• None of the above

• Ambidextrous

Which form of DNA is favored at low water concentrations?

• A form

• Z form

• None of the above

• B form