The Molecular Basis of Inheritance

These flashcards cover key terms and concepts related to DNA replication and the molecular basis of inheritance.

DNA replication

The process by which DNA makes a copy of itself, allowing genetic information to be passed from parent cell to daughter cells.

Gene

A unit of hereditary information consisting of a specific DNA sequence.

Adenine (A)

One of the four nitrogenous bases in DNA, pairs with Thymine (T).

Thymine (T)

One of the four nitrogenous bases in DNA, pairs with Adenine (A).

Guanine (G)

One of the four nitrogenous bases in DNA, pairs with Cytosine (C).

Cytosine (C)

One of the four nitrogenous bases in DNA, pairs with Guanine (G).

Semiconservative model

The model of DNA replication in which each daughter molecule has one old strand and one newly synthesized strand.

Okazaki fragments

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

Helicase

An enzyme that unwinds the DNA double helix at replication forks.

DNA polymerase

The enzyme responsible for synthesizing new DNA strands by adding nucleotides.

Primase

An enzyme that synthesizes a short RNA primer to initiate DNA replication.

Single-strand binding proteins

Proteins that stabilize single-stranded DNA during replication.

Topoisomerase

An enzyme that relieves the strain of twisting of DNA strands during replication.

Telomeres

Special nucleotide sequences at the ends of eukaryotic chromosomes that postpone the erosion of genes.

DNA ligase

An enzyme that joins Okazaki fragments on the lagging strand and seals nicks in DNA.

Nucleotide excision repair

A DNA repair process in which a nuclease cuts out and replaces damaged DNA.

Mutation

A change in the DNA sequence that can be passed on to the next generation and is a source of genetic variation.

Hydrogen bonds

Weak bonds that hold together nitrogenous base pairs in the DNA double helix.