DNA and Its Role in Heredity

These flashcards cover key vocabulary terms and concepts related to DNA and its role in heredity.

DNA

Deoxyribonucleic acid; the molecule that carries the genetic instructions for life.

Chromosomes

Structures within cells that contain DNA and proteins; they carry genetic information.

Purines

A category of nitrogenous bases in DNA that includes adenine (A) and guanine (G).

Pyrimidines

A category of nitrogenous bases in DNA that includes cytosine (C) and thymine (T).

Chargaff’s Rule

In DNA, the amount of purines equals the amount of pyrimidines (A=T and G=C).

Double Helix

The three-dimensional structure of DNA, consisting of two strands twisted around each other.

Semiconservative replication

The method of DNA replication in which each new DNA molecule consists of one old strand and one new strand.

DNA polymerase

An enzyme that synthesizes new strands of DNA by adding nucleotides to a growing chain.

Okazaki fragments

Short, newly synthesized DNA fragments that are formed on the lagging strand during DNA replication.

Telomeres

Repeated nucleotide sequences at the ends of eukaryotic chromosomes that protect them from degradation.

Repair mechanisms

Cellular systems that correct DNA errors, including proofreading, mismatch repair, and excision repair.