Genomics Glossary for Tour of the Genome

balanced translocation

a translocation where no genetic material is gained or lost in the cell, a person typically will be unaffected

beta-globin

a gene that encodes the component of hemoglobin. A point mutation within this gene causes Sickle Cell Disease

Bowl of Spaghetti model

model that depicts that uncondensed chromosomes (not going through cell division) are randomly entangeled in the nucleus. An experiment in the 1980s by Thomas and Christoph Cremer did not support this model.

chromatin

a thread of nucleosomes that is looped and packaged by proteins into tightly packed chromosomes during DNA replication

chromosome

a single molecule of DNA that is highly organized (by proteins) when cells divide. When cells are not dividing, this single molecule of DNA is less structured

Chromosome Territory model

model that depicts that each uncondensed chromosome (not going through cell division) occupies a specific space and only overlaps with its neighbors. An experiment in the 1980s by Thomas and Christoph Cremer supported this model.

exons

the pieces of RNA that we keep in the final messenger RNA molecule to code for proteins

gene

a unit of DNA that controls specific traits

genome

all the DNA in an organism

genomics

the study of a large number of genes and their interactions and/or of entire genomes (all of the DNA in an organism) to learn what kind of information is coded in these DNA sequences and how the DNA instructions are carried out

hemoglobin

a protein inside red blood cells that carries oxygen. A single point mutation within the beta-globin gene (which encodes a component of hemoglobin) can cause the hemoglobin protein to change shape which, in turn, causes Sickle Cell Disease by causing the red blood cell to take the shape of a sickle.

histone

proteins molecules that DNA is wrapped around

HIV (Human Immunodeficiency Virus)

a virus that attacks the immune system

homologous

term to describe chromosomes that are chomosome pairs. Of the pair, one chromosome comes from the mother and the other is from the father. They carry similar but not identical information.

intergenic region

region in DNA where no known genes exist

introns

the pieces of RNA that are removed from final messenger RNAs (these segments are not used to code for proteins)

karyotype

a description of the number and appearance of chromosomes in the nucleus of a eukaryotic cell

karyotyping

a visual tool that scientists use to profile and then analyze chromosomes in a sample of cells

mutation

alterations in the DNA

nucleosome

a unit that consists of a loop made of DNA and histones

nucleotides

the basic structural units of nucleic acids such as DNA and RNA. They are made up of a nucleoside coupled to a phosphate group

nucleus

a membrane bound structure in a cells that contains DNA

phenotype

observable traits

polymorphism

differences in DNA which can be used to identify individuals (eg. number of specific repeats within an intergenic region)

proteins

large complex molecules that perform many critical roles for an organism to function

Sickle Cell Disease

a genetic disorder that causes red blood cells to take on a deformed sickle shape instead of their normal disk shape, leading to poor circulation, pain, and anemia (low blood cell count).

translocation

part of a chromosome is transferred to a non-homologous chromosome

transposons

jumping genes which make up about half of the human genome by weight

unbalanced translocation

when a chromosome with extra or missing genetic material is inherited from a parent with a balanced translocation  which can lead to genetic disorders