The Molecular Basis of Inheritance

A set of vocabulary flashcards covering key concepts related to the molecular basis of inheritance and DNA structure, replication, and repair.

Nucleus

The membrane-bound organelle that contains the cell's chromosomes.

Nucleolus

A dense region within the nucleus where ribosomal RNA is produced.

Chromatin

A complex of DNA and proteins that forms chromosomes within the nucleus.

Eukaryote

An organism with complex cells that contain a nucleus and organelles.

Prokaryote

Single-celled organisms that lack a nucleus and complex organelles.

Antiparallel

Refers to the orientation of the two strands of DNA, running in opposite directions.

X-ray crystallography

A technique used to determine molecular structure by X-ray diffraction.

Double helix

The structure of DNA, consisting of two intertwined strands.

Histones

Proteins that package and order DNA into structural units called nucleosomes.

Nucleotide

The basic building block of DNA and RNA, consisting of a sugar, phosphate group, and nitrogenous base.

Nitrogenous bases

The components of nucleotides that include adenine (A), guanine (G), cytosine (C), and thymine (T).

Base pairing

The specific hydrogen bonding between nucleotides: adenine with thymine, and guanine with cytosine.

DNA replication

The process of copying DNA prior to cell division to ensure each daughter cell has the same genetic information.

Semi-conservative replication

A method of DNA replication where each new molecule contains one original strand and one new strand.

Helicase

An enzyme that unwinds the DNA double helix during replication.

Okazaki fragments

Short sequences of DNA nucleotides synthesized on the lagging strand during DNA replication.

DNA ligase

An enzyme that joins Okazaki fragments on the lagging strand.

Proofreading

The process by which DNA polymerases check and correct errors during DNA replication.

Mutation

A permanent change in the DNA sequence.

Nuclease

An enzyme that cuts DNA or RNA.