The Molecular Basis of Inheritance

These flashcards cover key concepts related to the molecular basis of inheritance, including DNA structure, replication processes, and the historical experiments that contributed to our understanding of genetics.

DNA (Deoxyribonucleic acid)

The molecule that carries genetic information in living organisms.

Double helix

The structure of DNA, composed of two strands coiled around each other.

Replication bubble

A region of DNA where the two strands have separated and where replication occurs.

Adenine (A)

A nitrogenous base in DNA that pairs with thymine (T).

Thymine (T)

A nitrogenous base in DNA that pairs with adenine (A).

Cytosine (C)

A nitrogenous base in DNA that pairs with guanine (G).

Guanine (G)

A nitrogenous base in DNA that pairs with cytosine (C).

Okazaki fragments

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

DNA polymerase III

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

Leading strand

The strand of DNA that is synthesized continuously during replication.

Lagging strand

The strand of DNA that is synthesized discontinuously in short segments during replication.

Semiconservative replication

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

Telomeres

Repeated nucleotide sequences at the ends of linear chromosomes that protect against DNA degradation.

Chargaff's rules

The observation that in DNA, the amount of adenine equals the amount of thymine, and the amount of guanine equals the amount of cytosine.

Transformation

A process by which a cell takes up and expresses foreign DNA.

Hershey-Chase experiment

A landmark experiment that concluded DNA is the genetic material in viruses, specifically bacteriophages.

Nucleotide excision repair

A DNA repair mechanism that removes and replaces damaged DNA segments.

Histone proteins

Proteins around which DNA is wrapped to form nucleosomes, aiding in DNA compaction.

Euchromatin

The less condensed form of chromatin that is accessible for transcription.

Heterochromatin

The more condensed form of chromatin that is usually not transcriptionally active.

Replication fork

The Y-shaped region where the DNA strands are unwound during replication.