Answer the following question in paragraph form. A) Define what a genome is and
ID: 170827 • Letter: A
Question
Answer the following question in paragraph form. A) Define what a genome is and what genome annotation is. What is the purpose of sequencing and annotating a genome? B) What have we learned about the human genome, now that it has been sequenced and is being annotated? C) Define the C-value paradox. D) Finally, compare and contrast the human genome with that of the Protist, Amoeba dubia, which has one of the largest genomes ever measured. In other words, explain the C-value paradox in terms of the Amoeba dubia and human genomes.
Explanation / Answer
A.
A genome is the complete set of genetic information in an organism. It provides all of the information the organism requires to function. In living organisms, the genome is stored in long molecules of DNA called chromosomes. Small sections of DNA, called genes, code for the RNA and protein molecules required by the organism. In eukaryotes, each cell's genome is contained within a membrane-bound structure called the nucleus. Prokaryotes, which contain no inner membranes, store their genome in a region of the cytoplasm called the nucleoid. The full range of RNA molecules expressed by a genome is known as its transcriptome, and the full assortment of proteins produced by the genome is called its proteome. The study and analysis of genomes is called genomics.
In modern molecular biology and genetics, a genome is the genetic material of an organism. It consists of DNA (or RNA in RNA viruses). The genome includes both the genes (the coding regions), the noncoding DNA and the genetic material of the mitochondria and chloroplasts. A genome is an organism’s complete set of DNA, including all of its genes. Each genome contains all of the information needed to build and maintain that organism and allow it to grow and develop.
DNA annotation or genome annotation is the process of identifying the locations of genes and all of the coding regions in a genome and determining what those genes do. Annotation is the process by which pertinent information about these raw DNA sequences is added to the genome databases. This involves describing different regions of the code and identifying which regions can be called genes.Genome annotation consists of three main steps:
B.
The HGP has helped to narrow the range of possible genes and to isolate certain candidates as contributing to specific diseases. some multitasking genes make more than one protein; in fact, the average gene may make three proteins. Also, genes appear to grab genetic code from other DNA segments. It also identified the locations of many human genes and provided information about their structure and organization. Researchers can discover the functions of particular genes and identify which genes are critical for life. We now know that our genome contains a range of 20,000 to 25,000 genes and about 3.2 billion A, C, G and T bases – the molecules that help make up the DNA code. An average-sized gene has about 3000 of these bases, though some genes are smaller and some are much bigger. The biggest known human gene, dystrophin, is made up of about 2.4 million bases. The Human Genome Project also gave us more detailed information about chromosomes. It turns out that chromosome 1 contains the most genes – 3168, while the Y chromosome has the fewest – about 344. Experimental annotation of the human genome is done by using microarray technology.
C.
C-Value Paradox: C value - the amount of DNA per haploid cell i. e, a gamete (usually expressed as picograms) or the number of kilobases per haploid cell or one half the amount in a diploid somatic cell of a eukaryotic organism.. Eukaryotic organisms appear to have 2-10 times as many genes as prokaryotes, But, they have many orders of magnitude more DNA in the cell.
D.
Amoeba dubia has 200 tmes more DNA than humans. This phenomenon is known as the C-value enigma or C-value paradox.. Amoeba dubia (an amoeba) have, respectively, C values that are 26 and 209 times the C value of humans.