Topic 5 - Molecular Genetics

A process used to visualize molecules three dimensionally, X-rays are diffracted as they pass through the molecule, and they bounce back to produce patterns that can be interpreted through mathematical equations

Special repair enzymes fix incorrectly paired nucleotides

Incorrectly placed nucleotides are excised or removed by nucleases, and the gap left over is filled in with the correct nucleotides

Short, repetitive nucleotide sequences that do not contain genes that cap the linear ends of eukaryotic chromosomes to avoid losing terminal genes during mitosis

Highly extended form of chromatin, available for transcription

Condensed chromatin, largely inaccessible to transcription enzymes and is generally not transcribed (ex. Barr bodies)

States that each gene codes for a polypeptide, which can be—or can constitute a part of—a protein

DNA —> RNA —> Protein

Substances or forces that interact with DNA in ways that cause mutations (ex. X-rays and other forms of radiation, asbestos)

Expression of different genes by cells with the same genome

The addition of methyl groups to DNA; it causes the DNA to be more tightly packaged, thus reducing gene expression

Acetyl groups are added to amino acids of histone proteins, thus making the chromatin less tightly packaged and encouraging transcription

Inheritance of traits transmitted by mechanisms not directly involving the nucleotide sequence (the DNA sequence is not changed, only its expression is changed)

Sets up the body plan and is a result of cytoplasmic determinants and inductive signals (is what determines head and tail, left and right, back and front

Master control genes that control pattern formation

Cancer-causing genes

Genes that code for proteins responsible for normal cell growth

Genes whose products normally inhibit cell division

A protein shell that surrounds the genetic material of a virus

Infect only a small variety of hosts (viruses)

Transcribes DNA from an RNA template

When, moving from one host to another, viruses pick up pieces of the first host’s DNA and carry it to the next cell to be infected (common in bacteria infected by viruses)

Usually not new but caused by existing viruses

Misfolded, infectious proteins that cause the misfolding of normal proteins in the brains of various animal species

Process of manipulating genes and genomes for practical purposes

Used to determine the complete nucleotide sequence of a DNA molecule and uses the principle of complementary base pairing

The process of manipulating organisms or their components for the purpose of making useful products

DNA that has been artificially made, using DNA from different sources, and often different species

Process by which scientists can produce multiple copies of specific segments of DNA that they can work with in the lab

A small, circular extra-chromosomal loop of DNA

Small differences in DNA sequences; can be detected by electrophoresis