Nucleotides
What are nucleotides the building blocks of?
DNA
What base pairs with adenine?
Thymine
What type of bond holds bases together?
Hydrogen bonds
What is the shape of DNA?
Double helix
How many hydrogen bonds are in C–G?
3
Name the three part of a nucleotide.
Phosphate / Sugar / Base
What base pairs with cytosine?
Guanine
What type of bond holds the backbone together?
Covalent bonds
What makes up the sides (backbone) of DNA?
Sugar and phosphate
Who are the two scientists most famous for discovering the structure of DNA?
Watson and Crick
What sugar is found in DNA?
Deoxyribose
What do we call the rule A–T and C–G?
Base pairing rules / Complementary base pairing
Which bond is weaker: hydrogen or covalent?
Hydrogen
What part of DNA forms the “rungs” of the ladder?
Base pairs
Which bases are purines?
Adenine and Guanine
How many parts make up a nucleotide?
Three
What would happen if adenine paired with cytosine?
It would be incorrect / mutation / disrupt DNA
Why are hydrogen bonds important for DNA function?
They allow DNA to unzip during replication
What does “complementary” mean in DNA?
Bases match specifically (A–T, C–G)
Which bases are pyrimidines?
Cytosine and Thymine
Which part of the nucleotide varies and carries genetic information?
Nitrogenous base
Why is base pairing important during DNA replication?
Ensures accurate copying of DNA
What would happen if covalent bonds broke instead of hydrogen bonds?
DNA structure would break apart completely
Why is DNA described as a twisted ladder?
Two strands twisted with base pairs in the middle
If a DNA strand reads A–C–G–T, what is the complementary strand?
T–G–C–A