ANSWERS: 3
  • I'm not sure what you mean. Genes on chromosomes in the cell are little more than stretches of nucleotides, which is why the human genome is a series of seemingly random A's T's C's and G's. Sets of three nucleotides are read together as a kind of code, and within the decoding region of the cell, they equal an amino acid. Amino acids are all joined together to form a protein. The protein is what is expressed that makes your eyes blue and your hair black or blonde. So- genes are formed of nucleotides Amino acids are coded by 3 nucleotides Proteins are made of amino acids. Sometimes one nucleotide gets accidentally replaced with another, which can change the amino acid, which changes the protein. This can form a new gene and -- Voila-- you have evolution! I hope this helps!
  • Two different views have been proposed for origins of genes (or proteins). One is that primordial genes evolved from random sequences. This view underlies the concept of modern in vitro evolution experiments that functional molecules (even proteins) evolved from random sequence-libraries. On the contrary, the second view reminds that "random sequences" would be an unusual state in which to find RNA or DNA, because it is their inherent nature to yield periodic structures during the course of semi-conservative replication. In this second view, the periodicity of DNA (or RNA) is responsible for emergence of primordial genes. Although recent reports on the variety of periodicities present in proteins, genes and genomes are consistent with the second view, it has yet to be experimentally tested. We assessed the significance of periodicities of DNA in the origin of genes by constructing such periodic DNAs. The results showed that periodic DNA produced ordered proteins at very high rates, which is in contrast to the fact that proteins with random sequences lack secondary structures. We concluded that periodicity played a pivotal role in the origin of many genes. The observation should pave the way for new experimental evolution systems for proteins. http://cat.inist.fr/?aModele=afficheN&cpsidt=13789513
  • A gene is the unit of heredity in every living organism. Genes are encoded in an organism's genome, composed of DNA or RNA, and direct the physical development and behavior of the organism. Most genes encode proteins, which are biological macromolecules comprising linear chains of amino acids that affect most of the chemical reactions carried out by the cell. Some genes do not encode proteins, but produce non-coding RNA molecules that play key roles in protein biosynthesis and gene regulation. Molecules that result from gene expression, whether RNA or protein, are collectively known as gene products. Most genes contain non-coding regions, that do not code for the gene products, but often regulate gene expression. A critical non-coding region is the promoter, a short DNA sequence that is required for initiation of gene expression. The genes of eukaryotic organisms often contain non-coding regions called introns which are removed from the messenger RNA in a process known as splicing. The regions that actually encode the gene product, which can be much smaller than the introns, are known as exons.

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