Discovery and Structure of Genes
Gregor Mendel proved the existence of genes using pea plants
Genes -
hereditary particles that carry hereditary information from parent to offspring
Genetics -
the study of the structure and function of genes and of the transmission of genes
between generations.
One of the most important scientific discoveries of the 20th century
James Watson and Francis Crick, 1953 - Proposed a structure for a complex molecule:
DNA (deoxyribonucleic acid)
- long double helix shape (twisted ladder)
Each upright is a chain of alternating sugar and phosphate molecules
Uprights linked by “steps” of Nitrogenous Bases
Adenine, Thymine, Cytosine, Guanine
Informational Macromolecule
- DNA is a very long molecule containing information encoded in its structure.
Thus, the structure of DNA encodes the genetic message
Gene - A segment of DNA
A molecule may have a sequence of many genes along its length
Information on it is used to direct the production or synthesis of other types of molecules
Replication
- A method for accurate self-reproduction of genetic material
Mutation - Mechanism of genetic change