Nucleic Acids and Heredity (DNA)

These flashcards cover key vocabulary related to the biological functions of nucleic acids, heredity, and the historical experiments that shaped our understanding of genetics.

Nucleon

The biological function of nucleon was not understood until the 1930s.

Proteins

Before the identification of DNA as hereditary material, proteins were thought to be the primary substance responsible for heredity.

Frederick Griffith

A scientist who demonstrated bacterial transformation and theorized about a 'transforming principle' between bacterial strains.

S strain

A virulent form of streptococcus pneumoniae that causes disease due to its smooth polysaccharide coating.

R strain

A non-virulent strain of streptococcus pneumoniae characterized by a rough outer coating that does not cause disease.

Transforming principle

The mysterious component hypothesized by Griffith to be responsible for transforming non-virulent R strain bacteria into virulent S strain.

Avery-MacLeod-McCarty experiment

An experiment that determined nucleic acids, not proteins, are the molecules of heredity.

Bacteriophage

A virus that infects bacteria, utilized by Hershey and Chase to study DNA as the genetic material.

Complementary base pairing

The pairing of nitrogen bases in DNA, where adenine pairs with thymine, and cytosine pairs with guanine.

Genome

The complete set of genes or genetic material present in a cell or organism.

Telomeres

Non-coding sequences at the ends of chromosomes that protect against information loss during DNA replication.

VNTRs (Variable Number Tandem Repeats)

Repeated sequences in the genome that vary among individuals and are often non-coding.

Histones

Proteins around which DNA is coiled to form chromatin, allowing it to fit in the nucleus.

Nucleotides

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

Double helix

The structure formed by two strands of DNA coiling around each other.