Q5TYU Genes important in the embryonic... [FREE SOLUTION]

Chapter 21: Q5TYU (page 440)

Genes important in the embryonic development of animals, such as homeobox-containing genes, have been relatively well conserved during evolution; that is, they are more similar among different species than are many other genes. Explain why this is.

Short Answer

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Homeobox genes are responsible for gene regulation or cell differentiation and morphogenesis of the organisms. They act as instructors during the development of all multicellular organisms.

The group of homeobox genes forms head-to-tail organizations in animals. They are preserved and get transformed to every generation from the ancestors.

Step by step solution

Definition of homeobox genes

The group of genes or DNA sequences that include around 180 base pairsregulating the anatomical features of the organisms can be called homeobox genes. These are known as developmental controlling genes. They are preserved throughout the evolution process in multicellular organisms.

Expression of homeobox genes

Homeobox genes are identified in functional regions of noncoding DNA. Putative regulatory elements regulate the expression of these genes.These are conserved because they are identical to known binding areas for regulatory proteins. The conserved elements participate in the functional divergence of genes and gene regulatory networks.

Reason for the conservation of homeobox genes

Understanding the function of the noncoding sequence of DNA and its preservation in the evolutionary process is the primary goal of comparative genetics. However, it is believed that specific protein-coding sequences are conserved to stabilize the organisms' selection process.

The coding part of the DNA is responsible for protein synthesis.The noncoding part of DNA, such as the homeobox gene, regulates gene expression in organisms.Thus, it is not changed during the process of evolution.