Assignment: Composition Of Nucleosomes

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Section (a): Composition of Nucleosomes
The nucleosome is the basic unit of the DNA and forms the building block of chromatin. Chromatin is a complex of the DNA and the cellular histone protein cores forming eukaryotic chromosomes. Structurally, the nucleosome core particle comprises 1.6 left-handed superhelical turns of DNA wound around a protein complex called the histone octamer, which consists of 2 copies each of the core histones attached to the central tetramer H3/H4. The latter is flanked by two H2A/H2B dimers (Kornberg 868).
The histone octamer, therefore, is a set of the 8 basic proteins whose fundamental structure of a single molecule includes three
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They form between 25–50% of the protein-coding genes of the multicellular organisms. The chicken lysozyme gene is an example of a solitary protein-coding gene with four exons and three introns. A genes family, on the other hand, is a group of genes bearing similar features as DNA’s building blocks (nucleotides) (Galluzzi 126). They contain instructions for making new products such as proteins. In some cases, genes are grouped together to form a family on the basis of product-protein interactions to achieve a certain…show more content…
However, they are non-functional, which explains why they are considered as relatives of functional genes. They arise from duplication or retrotransportation. Pseudogenes are critical to determining the historical evolution of genomic genes (Galluzzi 126). Ordinarily, they are identified with the aid of alignment programs such as FASTA. Tandemly repeated genes refers to a group of genes that are formed due to tandem duplication. The latter is a process through which a gene is duplicated and its copy retained next to the original one. They are vital to encoding a large number of genes at a time.

Section (B): The Difference between Orthologous and Paralogous Genes
While both genes are created within the same DNA ancestral sequence, orthologous genes diverge after evolution in a process called speciation, which gives rise to different species. Equally, paralogous genes also diverge after evolution. The difference is that diversion occurs within the same species (Nikolay). An example can be illustrated by the genes that give rise to haemoglobin and myoglobin, which are found in both humans and animals, suggesting that they have a common

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