Chapter 13: The Molecular Basis of Inheritance

Flashcards covering key vocabulary and concepts related to the molecular basis of inheritance, including DNA structure, replication, and genetic engineering.

Complementary Base Pairing

Adenine pairs with Thymine (A-T) and Guanine pairs with Cytosine (G-C) in DNA.

5' and 3' Ends of Nucleotide

Refers to the orientation of the carbon atoms in the sugar molecule; 5' end has a phosphate group, and 3' end has a hydroxyl (OH) group.

Antiparallel Strands

Refers to the arrangement of two DNA strands running in opposite directions; one runs 5' to 3' while the other runs 3' to 5'.

Nucleosome

A structure composed of DNA wrapped around histone proteins, serving as the fundamental unit of chromatin.

Heterochromatin

Tightly packed form of DNA that is generally not active in gene expression.

Euchromatin

Loosely packed form of DNA that is actively involved in transcription and gene expression.

Telomerase

An enzyme that extends the telomeres, allowing germ and stem cells to divide without losing genes.

Restriction Enzyme

Enzymes that cut DNA at specific sequences, used by bacteria as a defense mechanism.

Genetic Engineering

The direct manipulation of genes using biotechnology.

Cloning Vector

A DNA molecule, such as a plasmid, that carries foreign DNA into a host cell for replication.

Okazaki Fragments

Short segments of DNA synthesized on the lagging strand during DNA replication, joined together by DNA ligase.

Semiconservative Replication

Model of DNA replication in which each new DNA molecule consists of one original strand and one newly synthesized strand.

Thymine Dimer

A type of DNA damage caused by UV radiation where two thymine bases bond together, disrupting normal base pairing.

Telomere Erosion

Gradual shortening of telomeres during cell division, which can contribute to aging and decreased cell viability.

Nucleic Acid Hybridization

Base pairing of one nucleic acid strand to a complementary sequence on another nucleic acid strand.

DNA Polymerase

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

Ligase

An enzyme that joins DNA fragments together by sealing the sugar-phosphate backbone.