N

Nitrogenous base

A nitrogen-containing molecule having the chemical properties of a base. DNA contains the nitrogenous bases adenine (A), guanine (G), cytosine (C), and thymine (T).
See also: DNA

Northern blot

A gel-based laboratory procedure that locates mRNA sequences on a gel that are complementary to a piece of DNA used as a probe.
See also: DNA, library

Nuclear transfer

A laboratory procedure in which a cell's nucleus is removed and placed into an oocyte with its own nucleus removed so the genetic information from the donor nucleus controls the resulting cell. Such cells can be induced to form embryos. This process was used to create the cloned sheep "Dolly".
See also: cloning

Nucleic acid

A large molecule composed of nucleotide subunits.
See also: DNA

Nucleolar organizing region

A part of the chromosome containing rRNA genes.

Nucleotide

A subunit of DNA or RNA consisting of a nitrogenous base (adenine, guanine, thymine, or cytosine in DNA; adenine, guanine, uracil, or cytosine in RNA), a phosphate molecule, and a sugar molecule (deoxyribose in DNA and ribose in RNA). Thousands of nucleotides are linked to form a DNA or RNA molecule.
See also: DNA, base pair, RNA

Nucleus

The cellular organelle in eukaryotes that contains most of the genetic material.

Return to home page

A    B    C    D  E    F    G    H    I    J    K    L    M    N    O    P    Q    R    S    T    U    V    W    X    Y    Z    All Terms