Nucleotide: Definition, Structure, and Function
Nucleotide Definition A nucleotide is an organic molecule that is the building block of DNA and RNA. They also have functions related to cell signaling, …
Nucleoid: Definition and Function
Nucleoid Definition The nucleoid is the space within a prokaryotic cell where the genetic information, called the genophore, is found. Prokaryotes are divided into bacteria …
Nucleic acid: Definition, Structure, and Function
Definition A nucleic acid is a chain of nucleotides that stores genetic information in biological systems. It creates DNA and RNA, which store the information …
Nuclear Membrane (Nuclear Envelope)
Nuclear Membrane Definition The nuclear membrane, also called the nuclear envelope, is a double membrane layer that separates the contents of the nucleus from the …
Notochord: Definition, Structure, and Function
Notochord Definition The notochord is an elastic rod which extends through Chordate organisms, providing rigid support. In the more derived Chordates, the Vertebrates, the notochord …
Nonsense Mutation: Definition, Outcome, and Example
Nonsense Mutation Definition A nonsense mutation occurs when the sequence of nucleotides in DNA is changed in a way that stops the normal sequence of …
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Nondisjunction: Definition, Types, and Example
Definition Nondisjunction occurs when chromosomes do not separate properly during cell division. This produces cells with imbalanced chromosome numbers. Chromosomes contain the cell’s DNA, which …
NMDA Receptor: Definition, Structure, and Function
NMDA Receptor Definition NMDA receptors are neurotransmitter receptors that are located in the post-synaptic membrane of a neuron. They are proteins embedded in the membrane …
Nitrogenous Base: Definition, Example, and Function
Nitrogenous Base Definition Several chemicals with a similar cyclic structure, each known as a nitrogenous base, play several important roles in biology. Not only is …
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Neuron: Definition, Function, Parts, Structure, Types & More
Definition A neuron is a single nervous system cell that receives, processes, and transmits electrochemical messages from and to other cells. Neurons connect different areas …
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