What type of repetitive DNA is found at the telomere?

A highly conserved repetitive DNA sequence, (TTAGGG)n, present at the telomeres of human chromosomes.

What is the repetitive sequence on a telomere?

Telomeres are distinctive structures found at the ends of our chromosomes. They consist of the same short DNA sequence repeated over and over again. … In humans the telomere sequence is TTAGGG. This sequence is usually repeated about 3,000 times and can reach up to 15,000 base pairs? in length.

Is telomere repetitive DNA?

Telomeres do indeed play an essential role in stabilizing the ends of chromosomes, but they do not contain active genes. Instead, telomeres contain an array of highly repeated DNA sequences and specific binding proteins that form a unique structure at the end of the chromosome.

How are telomeres an example of repetitive DNA?

Telomeres are repetitive DNA sequences that are wrapped in specific protein complexes and located at the ends of linear chromosomes. Telomeres distinguish natural chromosome ends from DNA double-stranded breaks and thus promote genome stability.

What are the types of repetitive DNA?

Repetitive DNA can be divided into two classes: the tandem repetitive sequences (known as satellite DNA) and the interspersed repeats.

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What is telomere DNA?

A telomere is the end of a chromosome. Telomeres are made of repetitive sequences of non-coding DNA that protect the chromosome from damage. Each time a cell divides, the telomeres become shorter.

Are telomeres junk DNA?

The telomerase gene controls the activity of the telomerase enzyme, which helps produce telomeres, the caps at the end of each strand of DNA that protect the chromosomes within our cells. … “These DNA sequences tend to be considered as ‘junk DNA’ or dark matters in our genome, and they are difficult to study.

What type of cells have telomeres?

Telomerase is found in fetal tissues, adult germ cells, and also tumor cells. Telomerase activity is regulated during development and has a very low, almost undetectable activity in somatic (body) cells.

What does telomerase do to telomeres?

In egg and sperm cells, an enzyme called telomerase keeps adding more of the repeating sequence onto the end of DNA strands, so that the telomeres in these cells don’t shorten. In other cells, telomerase is less active, leading to the gradual shortening of telomeres over time.

Why are telomeres important in DNA?

Telomeres, the specific DNA–protein structures found at both ends of each chromosome, protect genome from nucleolytic degradation, unnecessary recombination, repair, and interchromosomal fusion. Telomeres therefore play a vital role in preserving the information in our genome.

What is moderately repetitive DNA?

Repetitive DNA: DNA sequences that are repeated in the genome. These sequences do not code for protein. … Another class termed moderately repetitive DNA consists of longer sequences, about 150-300 nucleotides, dispersed evenly throughout the genome, and includes what are called Alu sequences and transposons.

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What is unique DNA and repetitive DNA?

Eukaryotic genomes contain large amounts of repetitive DNA sequences that are present in many copies (thousands, in some cases). By contrast, coding regions of genes (which are typically present in a single copy per haploid genome) are referred to as unique-sequence DNA.

What is non repetitive DNA?

Nonrepetitive DNA is comprised of DNA sequences present in only one or in a small number of copies in a genome. It contrasts with repetitive DNA, especially Alu sequences, CpG Islands, Sines, Lines, microsatellite and minisatellite DNA.

Which of the following is an example of repetitive DNA?

A number of genetic diseases are associated with an increase in repetitive DNA sequences. The repeat sequence CpGpG is associated with the fragile X syndrome; other examples are Huntington’s chorea (CAG), myotonic dystrophy (CTG), and spinobulbar muscular dystrophy (CAG).

Are introns repetitive DNA?

Length: A gene is made of a long unique sequence, while repetitive DNA sequences are typically composed of short repeats. … Example: An example of a gene sequence is an exon, while an intron may be an example of non-coding, repetitive DNA.

Are transposons repetitive DNA?

Transposable genetic elements comprise a significant fraction of this repetitive DNA, and represent a ubiquitous class of middle-repetitive DNA in these organisms.