This is a glossary of terms commonly used in the study of genetics and related disciplines in biology. It is intended as introductory material for novices; for more specific and technical detail, please see the article corresponding to each term. Introductory articles in the field include: For a non-technical introduction to the topic, please see Introduction to genetics. ... Biology (from Greek Βìο meaning life and Λoγος meaning the study of, see below) is the study of life. ...

• DNA
• Gene
• Genetics
• Genome
• Mendelian inheritance

The structure of part of a DNA double helix. ... For other meanings of this term, see gene (disambiguation). ... For a non-technical introduction to the topic, please see Introduction to genetics. ... In biology the genome of an organism is the whole hereditary information of an organism that is encoded in the DNA (or, for some viruses, RNA). ... Mendelian inheritance (or Mendelian genetics or Mendelism) is a set of primary tenets relating to the transmission of hereditary characteristics from parent organisms to their children; it underlies much of genetics. ...

A

• Adenine: One of the four nucleotide bases in DNA or RNA; pairs with thymine in DNA or uracil in RNA.
• Allele: one of multiple alternative forms of a single gene, each of which is a viable DNA sequence occupying a given position, or locus on a chromosome. For example, in humans, one allele of the eye-color gene produces blue eyes and another allele of the eye-color gene produces brown eyes.

Adenine is one of the two purine nucleobases used in forming nucleotides of the nucleic acids DNA and RNA. In DNA, adenine binds to thymine via two hydrogen bonds to assist in stabilizing the nucleic acid structures. ... A nucleotide is a chemical compound that consists of a heterocyclic base, a sugar, and one or more phosphate groups. ... In genetics, an allele (pronounced al-eel or al-e-ul) is any one of a number of viable DNA codings occupying a given locus (position) on a chromosome. ...

B

• Base pair: A pair of nucleotide bases on complementary DNA or RNA strands organized in a double helix.

Base pairs, of a DNA molecule. ...

C

• Chromosome: a molecular "package" for carrying DNA in cells, organized as two double-helical DNA molecules that encode many genes. Some simple organisms have only one chromosome made of circular DNA, while most eukaryotes have multiple chromosomes made of linear DNA.
• Cytosine: One of the four nucleotide bases in DNA or RNA; pairs with guanine.

Figure 1: A representation of a condensed eukaryotic chromosome, as seen during cell division. ... Kingdoms Animalia - Animals Fungi Plantae - Plants Protista A eukaryote (IPA: ) is an organism with a complex cell or cells, in which the genetic material is organized into a membrane-bound nucleus or nuclei. ... Cytosine is one of the 5 main nucleobases used in storing and transporting genetic information within a cell in the nucleic acids DNA and RNA. It is a pyrimidine derivative, with a heterocyclic aromatic ring and two substituents attached (an amine group at position 4 and a keto group at...

D

• DNA: A polymeric molecule made of deoxyribonucleotides, hence then name deoxyribonucleic acid. Most often has the form of a "double helix", which consists of two paired DNA molecules and resembles a ladder that has been twisted. The "rungs" of the ladder are made of base pairs, or nucleotides with complementary hydrogen bonding patterns.

The structure of part of a DNA double helix. ... Polymer is a term used to describe large molecules consisting of repeating structural units, or monomers, connected by covalent chemical bonds. ... A deoxyribonucleotide is the monomer, or single unit, of DNA, or deoxyribonucleic acid. ... The Double-Helix are an alien race in the Wing Commander science fiction series. ... Base pairs, of a DNA molecule. ... A nucleotide is a chemical compound that consists of a heterocyclic base, a sugar, and one or more phosphate groups. ... In chemistry, a hydrogen bond is a type of attractive intermolecular force that exists between two partial electric charges of opposite polarity. ...

G

• Gene: the unit of heredity in living organisms, typically encoded in a sequence of nucleotide monomers that make up a long strand of DNA, or deoxyribonucleic acid. A particular gene can have multiple different forms, or alleles, which are defined by different sequences of DNA.

• Gene expression: The process in which the infomation encoded in a gene is converted into a form useful for the cell. The first step is transcription, which produces a messenger RNA molecule complementary to the DNA molecule on which a gene is encoded. For protein-coding genes, the second step is translation, in which the messenger RNA is read by the ribosome to produce a protein.

• Gene pool: the sum of all the alleles shared by members of a single population.

• Genetics: the field of biology that studies genes and their inheritance.

• Genotype: The complement of alleles present in a particular individual's genome that give rise to the individual's phenotype.

• Genome: the sum of all the genes in a particular organism or cell type.

• Guanine: One of the four nucleotide bases in DNA or RNA; pairs with cytosine.

For other meanings of this term, see gene (disambiguation). ... Gene expression, or simply expression, is the process by which a genes DNA sequence is converted into the structures and functions of a cell. ... For other meanings of this term, see gene (disambiguation). ... Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell. Cells in culture, stained for keratin (red) and DNA (green). ... Transcription is the process through which a DNA sequence is enzymatically copied by an RNA polymerase to produce a complementary RNA. Or, in other words, the transfer of genetic information from DNA into RNA. In the case of protein-encoding DNA, transcription is the beginning of the process that ultimately... The life cycle of an mRNA in a eukaryotic cell. ... The structure of part of a DNA double helix. ... For other meanings of this term, see gene (disambiguation). ... Translation is the second process of protein biosynthesis (part of the overall process of gene expression). ... Figure 1: Ribosome structure indicating small subunit (A) and large subunit (B). ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... The gene pool of a species or a population is the complete set of unique alleles that would be found by inspecting the genetic material of every living member of that species or population. ... For a non-technical introduction to the topic, please see Introduction to genetics. ... The genotype is the specific genetic makeup (the specific genome) of an individual, in the form of DNA. Together with the environmental variation that influences the individual, it codes for the phenotype of that individual. ... In biology the genome of an organism is the whole hereditary information of an organism that is encoded in the DNA (or, for some viruses, RNA). ... Guanine is one of the five main nucleobases found in the nucleic acids DNA and RNA; the others being adenine, cytosine, thymine, and uracil. ...

L

• Locus: a location on a chromosome where a particular gene resides.

The word locus (plural loci) is Latin for place: In biology and evolutionary computation, a locus is the position of a gene (or other significant sequence) on a chromosome. ...

M

• Mutation: is a change in the base pair sequence of DNA or RNA.

In biology, mutations are changes to the genetic material (either DNA or RNA). ...

N

• Nucleotide: one of the four monomers that make up a DNA molecule.

A nucleotide is a chemical compound that consists of a heterocyclic base, a sugar, and one or more phosphate groups. ...

P

• Phenotype: The observable physical or behavioral traits of an organism, largely determined by the organism's genotype.
• Protein: A linear polymeric molecule made of of amino acids linked by peptide bonds. Proteins carry out the majority of chemical reactions that occur inside the cell.

Individuals in the mollusk species Donax variabilis show diverse coloration and patterning in their phenotypes. ... A crab is an example of an organism. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... Polymer is a term used to describe large molecules consisting of repeating structural units, or monomers, connected by covalent chemical bonds. ... Phenylalanine is one of the standard amino acids. ... A peptide bond is a chemical bond formed between two molecules when the carboxyl group of one molecule reacts with the amino group of the other molecule, releasing a molecule of water (H2O). ... A chemical reaction occurs when vapours of hydrogen chloride and ammonia meet to form a cloud of a new substance, ammonium chloride Chemical reactions is a process that results in the interconversion of chemical substances [1]. The substance or substances initially involved in a chemical reaction are called reactants. ... Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell. Cells in culture, stained for keratin (red) and DNA (green). ...

T

• Thymine: One of the four nucleotide bases in DNA; pairs with adenine. In RNA, thymine is replaced with uracil.

• Transcription: The first step in gene expression, in which a messenger RNA molecule complementary to particular gene encoded in DNA is synthesized by enzymes called RNA polymerases. To produce a functional protein, transcription is followed by translation.

• Translation: The second step in gene expression, in which a messenger RNA molecule is read by the ribosome to produce a functional protein. Translation is always preceded by transcription.

For the similarly-spelled vitamin compound, see Thiamine Thymine, also known as 5-methyluracil, is a pyrimidine nucleobase. ... Transcription is the process through which a DNA sequence is enzymatically copied by an RNA polymerase to produce a complementary RNA. Or, in other words, the transfer of genetic information from DNA into RNA. In the case of protein-encoding DNA, transcription is the beginning of the process that ultimately... The life cycle of an mRNA in a eukaryotic cell. ... Ribbon diagram of the enzyme TIM, surrounded by the space-filling model of the protein. ... RNAP from pictured during elongation. ... Translation is the second process of protein biosynthesis (part of the overall process of gene expression). ... The life cycle of an mRNA in a eukaryotic cell. ... Figure 1: Ribosome structure indicating small subunit (A) and large subunit (B). ...

U

• Uracil: One of the four nucleotide bases in RNA; pairs with adenine. In DNA, uracil is replaced with thymine.