Dictionary > Repeated sequences

Repeated sequences

Definition
noun
(molecular biology) Multiple copies of nucleotide sequences in the nucleic acids (i.e. DNA or RNA) throughout the genome
Supplement
The repeated sequences occur as multiple copies of nucleic acids in the genome. These repeats may involve the DNA or the RNA. In repetitive DNA, for instance, stretches of DNA repeats occur in the genome as either in tandem or interspersed along the genome. These repeats are found in various organisms. In humans, there may be over two-thirds of repetitive DNA in the genome.1
There are three major types of repeated sequences: (1) terminal repeats, (2) tandem repeats, and (3) interspersed repeats. The terminal repeats are repeated sequences that occur terminally, i.e. on both the 5′ and 3′ ends of a sequence. Tandem repeats are repeated sequences in which the copies lie adjacent to each other. These include satellite DNA, minisatellites and macrosatellites. Interspersed repeats (also called interspersed nuclear elements) are repeated sequences in which the copies are dispersed throughout the genome. Unlike tandem repeats, the interspersed repeats have copies that are nonadjacent. These include the transposable elements (transposons), such as DNA transposons and retrotransposons.
See also:

Reference(s):

1 de Koning A. P., Gu, W., Castoe, T. A., Batzer, M. A., & Pollock, D. D. (2011). “Repetitive elements may comprise over two-thirds of the human genome.” PLoS Genet., 7(12): e1002384.


You will also like...

Independent Assortment and Crossing Over
Independent Assortment and Crossing Over

This tutorial describes the independent assortment of chromosomes and crossing over as important events in meiosis. Read..

Still Water Community Plants
Still Water Community Plants

This tutorial looks at the adaptations of freshwater plants for them to thrive in still water habitats. Familiarize your..

Carbohydrates, fats and proteins - dietary sources
A Balanced Diet – Carbohydrates and Fat

Apart from vitamins, the human body also requires high energy sources such as carbohydrates and fats. If you want an ove..

Ecological Research Measuring & Analysis
Ecological Research: Measuring & Analysis

This lesson is about the methods used for ecological research, such as quadrat and transect sampling, canopy fogging, an..

Chromosome Mutations
Chromosome Mutations

Mutations can also influence the phenotype of an organism. This tutorial looks at the effects of chromosomal mutations, ..

primitive arthropods
Arthropods

The arthropods were assumed to be the first taxon of species to possess jointed limbs and exoskeleton, exhibit more adva..

Related Articles...

No related articles found

See all Related Topics