Q25.5-3CC - Campbell Biology

Question

Given that changes in morphology are often caused by changes in the regulation of gene expression, predict whether noncoding DNA is likely to be affected by natural selection. See Concept 18.3 to review noncoding DNA and regulation of gene expression.

Step-by-Step Solution

Answer

When there are morphological changes due to gene expression regulation, natural selection will affect the noncoding DNA.

Step 1: Gene expression

The field of genetics describes an inheritance unit found in biological organisms; this heredity unit is responsible for holding information to encode protein in the living cell and is called a gene.

The regulatory process in which a gene is expressed and its nucleotide sequence is used by the cell to make RNA and then convert it into a protein molecule is called gene expression.

Step 2: Natural selection

Biological organisms can show the adaptation and variation in their novel environment to make new offspring. This mechanism occurs due to natural selection.

The variety of beaks found in Galapagos finches is an example of natural selection.

Step 3: Effects of natural selection on noncoding DNA

Natural selection strongly affects the noncoding genome or DNA (do not instruct gene to synthesize protein). This is due to the alteration of gene expression regulation (switching on and off) by control elements contained within a DNA.