Deoxyribonucleic acid, better known as DNA, is crucial to life on Earth. The questions and answers in this list are taken from the Top Questions sections of the articles on DNA, recombinant DNA, and chloroplast, where you can find more questions answered.
What is DNA made of?
DNA; human genomeThe human genome is made up of approximately three billion base pairs of deoxyribonucleic acid (DNA). The bases of DNA are adenine (A), thymine (T), guanine (G), and cytosine (C).Encyclopædia Britannica, Inc.DNA is made of nucleotides. A nucleotide has two components: a backbone, made from the sugar deoxyribose and phosphate groups, and nitrogenous bases, known as cytosine (C), thymine (T), adenine (A), and guanine (G). Genetic code is formed through different arrangements of the bases.
What does DNA do?
DNA and protein synthesisDNA in the cell nucleus carries a genetic code, which consists of sequences of adenine (A), thymine (T), guanine (G), and cytosine (C) (Figure 1). RNA, which contains uracil (U) instead of thymine, carries the code to protein-making sites in the cell. To make RNA, DNA pairs its bases with those of the “free” nucleotides (Figure 2). Messenger RNA (mRNA) then travels to the ribosomes in the cell cytoplasm, where protein synthesis occurs (Figure 3). The base triplets of transfer RNA (tRNA) pair with those of mRNA and at the same time deposit their amino acids on the growing protein chain. Finally, the synthesized protein is released to perform its task in the cell or elsewhere in the body.Encyclopædia Britannica, Inc.DNA is an organic chemical that contains genetic information and instructions for protein synthesis. It is found in most cells of every organism. DNA is a key part of reproduction in which genetic heredity occurs through the passing down of DNA from parent or parents to offspring.
Who discovered the structure of DNA?
The discovery of DNA’s double-helix structure is credited to the researchers James Watson and Francis Crick, who, with fellow researcher Maurice Wilkins, received a Nobel Prize in 1962 for their work. Many believe that Rosalind Franklin should also be given credit, since she made the revolutionary photo of DNA’s double-helix structure, which was used as evidence without her permission.
Can you edit DNA?
Gene editing today is mostly done through a technique called Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR), adopted from a bacterial mechanism that can cut out specific sections in DNA. One use of CRISPR is the creation of genetically modified organism crops.
What is recombinant DNA technology?
recombinant DNASteps involved in the engineering of a recombinant DNA molecule.Encyclopædia Britannica, Inc.Recombinant DNA technology is the joining together of DNA molecules from two different species. The recombined DNA molecule is inserted into a host organism to produce new genetic combinations that are of value to science, medicine, agriculture, and industry. Since the focus of all genetics is the gene, the fundamental goal of laboratory geneticists is to isolate, characterize, and manipulate genes. Recombinant DNA technology is based primarily on two other technologies, cloning and DNA sequencing. Cloning is undertaken in order to obtain the clone of one particular gene or DNA sequence of interest. The next step after cloning is to find and isolate that clone among other members of the library (a large collection of clones). Once a segment of DNA has been cloned, its nucleotide sequence can be determined. Knowledge of the sequence of a DNA segment has many uses.
Do chloroplasts have DNA?
Unlike most other organelles, chloroplasts and mitochondria have small circular chromosomes known as extranuclear DNA. Chloroplast DNA contains genes that are involved with aspects of photosynthesis and other chloroplast activities. It is thought that both chloroplasts and mitochondria are descended from free-living cyanobacteria, which could explain why they possess DNA that is distinct from the rest of the cell.
