Chapter 12: DNA: The Molecule of Heredity

A set of vocabulary flashcards covering essential terms related to DNA structure, function, replication, and mutations for exam preparation.

DNA

The molecule of heredity that carries genetic information.

Double Helix

The structure of DNA consisting of two strands that coil around each other.

Complementary Base Pairs

Pairs of nitrogenous bases in DNA that bond together, specifically adenine with thymine (A-T) and cytosine with guanine (C-G).

Shargaff’s Rule

The principle that in DNA, the amount of adenine equals thymine (A=T) and the amount of cytosine equals guanine (C≡G).

Gene

A discrete unit of hereditary information located on chromosomes.

Chromosome

A structure within cells that contains DNA and protein, which carry genetic information.

Bacteriophage

A virus that infects bacteria and is used in experiments to determine the nature of genetic material.

Transformed Bacteria

Bacteria that have taken up DNA from their surroundings, leading to new traits.

DNA Replication

The process by which DNA makes a copy of itself, occurring before cell division.

Semiconservative Replication

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

Okazaki Fragment

Short segments of DNA synthesized on the lagging strand during DNA replication.

Point Mutation

A mutation affecting a single nucleotide in DNA.

DNA Repair System

The cellular mechanisms that fix errors or damages in the DNA.

Mutations

Changes in the DNA sequence that can be neutral, harmful, or beneficial.

Phosphodiester Linkage

The bond that connects adjacent nucleotides in a DNA strand.

Exonuclease Activity

The proofreading function of DNA polymerase that corrects errors during DNA replication.