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Table of content
DNA - Deoxyribonucleic Acid
DNA History
Deoxyribonucleic Acid Type (DNA)
The purposes of DNA
What is DNA Sequencing ?
Chromosome
How many chromosomes do individuals possess?
DNA - Deoxyribonucleic Acid
The DNA structure can be compared to a twisted ladder. As depicted in the diagram above, this structure is known as a double helix. Nucleotides, which have a nitrogen base, a phosphate group, and a carbon-sugar group, are the fundamental components of DNA. Each DNA strand is created by the nucleotides being joined by groups of sugar and phosphate. Thymine (T), Guanine (G), Adenine (A), and Cytosine (C) are the four types of nitrogen bases.Human DNA contains about 3 billion bases, and more than 99 percent of them share a similar structure across all individuals. Similar to how the letters of the alphabet occur in a specific order to form words and sentences, the order, or sequence, of these bases represents the information accessible for constructing and maintaining an organism.
DNA History
The discovery of DNA was made by Swiss biologist Johannes Friedrich Miescher in 1869 while he was studying white blood cells, or WBC. Later, James Watson and Francis Crick used experimental data to determine the DNA molecule's double helix shape. Finally, it was determined that DNA is in charge of handling a human's genetic dataDeoxyribonucleic Acid Type (DNA)
There are several varieties of deoxyribonucleic acid, including DNA in the A-, B-, and Z-forms. Below, these three categories are described in depth.|
A form DNA |
There are several varieties of deoxyribonucleic acid, including DNA in the A-, B-, and Z-forms. Below, these three categories are described in depth. |
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B form DNA |
Watson and Crick provided a proposal for a double-helical DNA structure in their paper from 1953. They proposed a right-hand helix with two DNA strands coiled around the same axis. H-bonding between the bases of the two strands keeps them together. If pyrimidine on one strand is always paired with purine on the other, then these bases fit into the double-helical paradigm. |
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Z form DNA |
Left-handed DNA is DNA in the Z form. Alexander Rich and Andres Wang observed that it occurs when the G and C nucleotides are in different conformations when the DNA is in an alternating purine-pyrimidine sequence like GCGCGC, resulting in the zigzag pattern. Since the Z form of DNA is situated before a gene's beginning point, it is hypothesised that it controls the gene. |
The purposes of DNA
1.With the aid of hormones, enzymes, and certain RNAs, DNA affects the metabolic responses of the cells.2. DNA is the genetic substance that contains every piece of passed-down knowledge encoded in its nitrogenous base structure.
3. From one generation to the next, DNA transfers the genetic information from one cell to its daughter cells.
4. Each individual has a distinct DNA that doesn't match that of others. In DNA fingerprinting, a technique used to identify a person from their DNA, this DNA feature is exploited.
5. DNA is used in the following processes in addition to storing genetic information.
- Replication process
- Mutations
- Transcription
- Cellular Metabolism
- DNA Fingerprinting
- Gene Therapy
Non-Coding DNA Types
The table given below consists of lists of different types of non-coding DNA| Satellite DNA | It consists of DNA sequences that repeat tandemly in short lengths. Centromeres and the structural elements of heterochromatin are frequently employed in DNA profiling. |
| Telomeres | The repetitive DNA sequences that serve as a chromosome's last line of defence against chromosomal degradation during replication are those. |
| Introns | These are the non-coding sequences that are cut out of genes by RNA splicing before mRNA is produced. |
| Non-coding RNA genes | genes with no codons, genes for RNA molecules, such as tRNA, that do not convert into proteins. |
| Gene regulatory sequences | sequences that take part in the transcription process includes enhancers, silencers, and promoters |
What is DNA Sequencing ?
It is a method for determining the nucleotide sequence's base order. Chain-terminating dideoxynucleotides are a typical component of DNA sequencing techniques. Application of DNA Sequencing: To prepare samples for base sequencing, DNA sequencing uses nucleotides that include deoxyribonucleic acid to halt DNA replication.Chromosome
The nucleus of the cell contains DNA molecules arranged in a thread-like structure called the chromosomes, which are located there. DNA is tightly wound around proteins called histones that support the structure of DNA on every chromosome. Every chromosome features a centromere, which is a point of constriction that separates the chromosome into two arms.- P-arm: The chromosome's short arm is referred to as the P-arm.
- Q-arm: The Q-arm refers to the long arm of the chromosome.
How many chromosomes do individuals possess?
There are 46 chromosomes in all, divided into 23 pairs in humans. The autosomes present in both males and females are twenty-two of these pairs. The twenty-third pair, often known as the sex chromosome, differs between males and females. Males have one X and one Y chromosome, or XY, whereas females have two copies of the X chromosome, or XX.Also check,
How many genes are in a chromosome?
Each chromosome contains hundreds to thousands of genes, which carry the instructions for making proteins. Each of the estimated 30,000 genes in the human genome makes an average of three proteins.What are chromosomes composed of?
A chromosome is made up of proteins and DNA organized into genes. Each cell normally contains 23 pairs of chromosomes.
Where are chromosomes stored?
the nucleus
