Double helix — Science definition
The twisted-ladder shape of a DNA molecule, formed by two strands winding around each other.
Where it is taught
- DNA Structure & Replication — DNA, Inheritance & Gene Expression, Life Science: Biology, Grade 10
In use
Link many nucleotides together and you get a single strand; bring two strands together and they twist into DNA's famous double helix — the shape of a ladder gently spiraled around its own length.
DNA Structure & Replication
Questions using double helix
Problem 1
Replication is described as semiconservative because each new double helix contains
- two new strands
- one original strand and one new strand
- only original strands
- a mixture of RNA and DNA
Answer and explanation
one original strand and one new strand
The two original strands separate and each serves as a template, so every product keeps one original strand.
Taught alongside
- nucleotide
- complementary base pairing
- semiconservative replication
- DNA polymerase
- antiparallel
- semiconservative