DNA Structure and Base Pairing

This video explains DNA base pairing, focusing on how nucleotides form double-stranded DNA through hydrogen bonding between nitrogenous bases. It covers the roles of purines and pyrimidines, emphasizing the stability of adenine-thymine and guanine-cytosine pairings. The video concludes with a call to action for viewers to engage with the content.

What is the basic structural unit of DNA?

• Lipid

• Nucleotide

• Amino acid

• Protein

Which type of bond is responsible for the pairing of nitrogenous bases in DNA?

• Covalent bond

• Ionic bond

• Hydrogen bond

• Metallic bond

What characteristic of nitrogen makes it attract electrons in a hydrogen bond?

• Its size

• Its color

• Its electronegativity

• Its mass

Which of the following are purines?

• Cytosine and Uracil

• Uracil and Thymine

• Adenine and Guanine

• Thymine and Cytosine

Why do purines pair with pyrimidines in DNA?

• To create stronger bonds

• To increase DNA length

• To enhance DNA flexibility

• To maintain a consistent DNA width

In DNA, which base does adenine pair with?

• Thymine

• Uracil

• Guanine

• Cytosine

How many hydrogen bonds connect adenine and thymine?

• Four

• Three

• Two

• One

Which base does guanine pair with in DNA?

• Adenine

• Cytosine

• Thymine

• Uracil

How many hydrogen bonds are formed between guanine and cytosine?

• Four

• Three

• Two

• One

In RNA, which base pairs with adenine?

• Guanine

• Uracil

• Cytosine

• Thymine