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[23] [24] If the DNA is replicated faster than the bacterial cells divide, multiple copies of the chromosome can be present in a single cell, and if the cells divide faster than the DNA can be replicated, multiple replication of the chromosome is initiated before the division occurs, allowing daughter cells to inherit complete genomes and ...
The process of DNA replication is semiconservative; that is, the copy of the genome inherited by each daughter cell contains one original and one newly synthesized strand of DNA. [ 51 ] : 5.2 The rate of DNA replication in living cells was first measured as the rate of phage T4 DNA elongation in phage-infected E. coli and found to be ...
Genes express their functional effect through the production of proteins, which are molecules responsible for most functions in the cell. Proteins are made up of one or more polypeptide chains, each composed of a sequence of amino acids. The DNA sequence of a gene is used to produce a specific amino acid sequence.
Gene duplication is a major mechanism through which new genetic material is generated during molecular evolution. For example, the olfactory receptor gene family is one of the best-documented examples of pseudogenes in the human genome. More than 60 percent of the genes in this family are non-functional pseudogenes in humans.
Since traits come from the genes in a cell, putting a new piece of DNA into a cell can produce a new trait. This is how genetic engineering works. For example, rice can be given genes from a maize and a soil bacteria so the rice produces beta-carotene , which the body converts to vitamin A. [ 19 ] This can help children with Vitamin A deficiency.
All living cells contain both DNA and RNA (except some cells such as mature red blood cells), while viruses contain either DNA or RNA, but usually not both. [15] The basic component of biological nucleic acids is the nucleotide , each of which contains a pentose sugar ( ribose or deoxyribose ), a phosphate group, and a nucleobase . [ 16 ]
“[Eighteen] of the 19 chromosomes of the South American lungfish are each individually larger than the entire human genome with its almost 3 billion bases,” the researchers wrote in the paper ...
The discovery of DNA as the blueprint for life and breakthroughs in molecular genetics research came from the combined works of many scientists. In 1869, chemist Johann Friedrich Miescher, who was researching the composition of white blood cells, discovered and isolated a new molecule that he named nuclein from the cell nucleus, which would ultimately be the first discovery of the molecule DNA ...